DataView.ToTable DataView.ToTable DataView.ToTable DataView.ToTable Method

Определение

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

Перегрузки

ToTable(Boolean, String[]) ToTable(Boolean, String[]) ToTable(Boolean, String[]) ToTable(Boolean, String[])

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

ToTable(String) ToTable(String) ToTable(String) ToTable(String)

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

ToTable(String, Boolean, String[]) ToTable(String, Boolean, String[]) ToTable(String, Boolean, String[]) ToTable(String, Boolean, String[])

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

ToTable() ToTable() ToTable() ToTable()

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

Комментарии

Возвращенный DataTable поддерживаются значения следующих свойств из источника DataTable: Namespace, Prefix, Locale, и CaseSensitive.The returned DataTable maintains the values of the following properties from the source DataTable: Namespace, Prefix, Locale, and CaseSensitive. Каждый столбец в результате DataTable содержит идентичную копию все соответствующие свойства в базовом DataTable.Each column in the resulting DataTable contains an identical copy of all the corresponding properties in the underlying DataTable.

DataRow Экземпляров в возвращаемом DataTable будет содержать значения, которые соответствуют семантике среды CLR.The DataRow instances in the returned DataTable will contain values that are consistent with CLR semantics. То есть для всех типов данных, кроме определяемые пользователем типы, соответствующие значения столбцов копируются по значению.That is, for all data types besides user-defined types, the corresponding column values are copied by value. Для типов данных, определяемых пользователем данных в столбце копируется по ссылке.For user-defined data types, the column data is copied by reference.

ToTable(Boolean, String[]) ToTable(Boolean, String[]) ToTable(Boolean, String[]) ToTable(Boolean, String[])

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

public:
 System::Data::DataTable ^ ToTable(bool distinct, ... cli::array <System::String ^> ^ columnNames);
public System.Data.DataTable ToTable (bool distinct, params string[] columnNames);
member this.ToTable : bool * string[] -> System.Data.DataTable
Public Function ToTable (distinct As Boolean, ParamArray columnNames As String()) As DataTable

Параметры

distinct
Boolean Boolean Boolean Boolean

При значении true возвращенный объект DataTable содержит строки с различными значениями для всех столбцов.If true, the returned DataTable contains rows that have distinct values for all its columns. Значение по умолчанию — false.The default value is false.

columnNames
String[]

Массив строк, содержащий список имен столбцов, которые должны быть включены в возвращенный объект DataTable.A string array that contains a list of the column names to be included in the returned DataTable. Объект DataTable, содержащий указанные столбцы в том порядке, в каком они отображаются внутри массива.The DataTable contains the specified columns in the order they appear within this array.

Возвраты

Новый экземпляр класса DataTable, который содержит запрошенные строки и столбцы.A new DataTable instance that contains the requested rows and columns.

Примеры

В следующем образце консольного приложения создает DataTable, заполняет DataTable с данными, сортирует DataViewи наконец создает DataTable с только что двумя столбцами, ограниченное строками, в которых все значения являются уникальными.The following console application example creates a DataTable, fills the DataTable with data, sorts the DataView, and finally creates a DataTable with just two columns, limited to rows in which all values are unique.

private static void DemonstrateDataView()
{
    // Create a DataTable with three columns.
    DataTable table = new DataTable("NewTable");
    Console.WriteLine("Original table name: " + table.TableName);
    DataColumn column = new DataColumn("ID", typeof(System.Int32));
    table.Columns.Add(column);

    column = new DataColumn("Category", typeof(System.String));
    table.Columns.Add(column);

    column = new DataColumn("Product", typeof(System.String));
    table.Columns.Add(column);

    column = new DataColumn("QuantityInStock", typeof(System.Int32));
    table.Columns.Add(column);

    // Add some items.
    DataRow row = table.NewRow();
    row.ItemArray = new object[] { 1, "Fruit", "Apple", 14 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 2, "Fruit", "Orange", 27 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 3, "Bread", "Muffin", 23 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 4, "Fish", "Salmon", 12 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 5, "Fish", "Salmon", 15 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 6, "Bread", "Croissant", 23};
    table.Rows.Add(row);

    // Mark all rows as "accepted". Not required
    // for this particular example.
    table.AcceptChanges();

    // Print current table values.
    PrintTableOrView(table, "Current Values in Table");

    DataView view = new DataView(table);
    view.Sort = "Category";
    PrintTableOrView(view, "Current Values in View");

    DataTable newTable = view.ToTable(true, "Category", "QuantityInStock");
    PrintTableOrView(newTable, "Table created from sorted DataView");
    Console.WriteLine("New table name: " + newTable.TableName);

    Console.WriteLine("Press any key to continue.");
    Console.ReadKey();
}

private static void PrintTableOrView(DataView dv, string label)
{
    System.IO.StringWriter sw;
    string output;
    DataTable table = dv.Table;

    Console.WriteLine(label);

    // Loop through each row in the view.
    foreach (DataRowView rowView in dv)
    {
        sw = new System.IO.StringWriter();

        // Loop through each column.
        foreach (DataColumn col in table.Columns)
        {
            // Output the value of each column's data.
            sw.Write(rowView[col.ColumnName].ToString() + ", ");
        }
        output = sw.ToString();
        // Trim off the trailing ", ", so the output looks correct.
        if (output.Length > 2)
        {
            output = output.Substring(0, output.Length - 2);
        }
        // Display the row in the console window.
        Console.WriteLine(output);
    }
    Console.WriteLine();
}

private static void PrintTableOrView(DataTable table, string label)
{
    System.IO.StringWriter sw;
    string output;

    Console.WriteLine(label);

    // Loop through each row in the table.
    foreach (DataRow row in table.Rows)
    {
        sw = new System.IO.StringWriter();
        // Loop through each column.
        foreach (DataColumn col in table.Columns)
        {
            // Output the value of each column's data.
            sw.Write(row[col].ToString() + ", ");
        }
        output = sw.ToString();
        // Trim off the trailing ", ", so the output looks correct.
        if (output.Length > 2)
        {
            output = output.Substring(0, output.Length - 2);
        }
        // Display the row in the console window.
        Console.WriteLine(output);
    } //
    Console.WriteLine();
}
Private Sub DemonstrateDataView()
    ' Create a DataTable with three columns.
    Dim table As DataTable = New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As DataColumn = New DataColumn("ID", GetType(System.Int32))
    table.Columns.Add(column)

    column = New DataColumn("Category", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("Product", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("QuantityInStock", GetType(System.Int32))
    table.Columns.Add(column)


    ' Add some items.
    Dim row As DataRow = table.NewRow()
    row.ItemArray = New Object() {1, "Fruit", "Apple", 14}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {2, "Fruit", "Orange", 27}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {3, "Bread", "Muffin", 23}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {4, "Fish", "Salmon", 12}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {5, "Fish", "Salmon", 15}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {6, "Bread", "Croissant", 23}
    table.Rows.Add(row)

    ' Mark all rows as "accepted". Not required
    ' for this particular example.
    table.AcceptChanges()

    ' Print current table values.
    PrintTableOrView(table, "Current Values in Table")

    Dim view As DataView = New DataView(table)
    view.Sort = "Category"
    PrintTableOrView(view, "Current Values in View")

    Dim newTable As DataTable = view.ToTable( _
        True, "Category", "QuantityInStock")
    PrintTableOrView(newTable, "Table created from sorted DataView")
    Console.WriteLine("New table name: " & newTable.TableName)

    Console.WriteLine("Press any key to continue.")
    Console.ReadKey()
End Sub

Private Sub PrintTableOrView(ByVal dv As DataView, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String
    Dim table As DataTable = dv.Table

    Console.WriteLine(label)

    ' Loop through each row in the view.
    For Each rowView As DataRowView In dv
        sw = New System.IO.StringWriter

        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(rowView(col.ColumnName).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

Private Sub PrintTableOrView(ByVal table As DataTable, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String

    Console.WriteLine(label)

    ' Loop through each row in the table.
    For Each row As DataRow In table.Rows
        sw = New System.IO.StringWriter
        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(row(col).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

В этом примере в окне консоли отображаются следующие выходные данные:The example displays the following output in the console window:

Original table name: NewTable  
Current Values in Table  
1, Fruit, Apple, 14  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  
4, Fish, Salmon, 12  
5, Fish, Salmon, 15  
6, Bread, Croissant, 23  

Current Values in View  
3, Bread, Muffin, 23  
6, Bread, Croissant, 23  
4, Fish, Salmon, 12  
5, Fish, Salmon, 15  
1, Fruit, Apple, 14  
2, Fruit, Orange, 27  

Table created from sorted DataView  
Bread, 23  
Fish, 12  
Fish, 15  
Fruit, 14  
Fruit, 27  

New table name: NewTable  

Комментарии

Так как этот метод не позволяет указать имя для выходных данных DataTable, его имя совпадает с именем источника DataTable.Because this method does not let you specify the name for the output DataTable, its name is the same as the name of the source DataTable.

ToTable(String) ToTable(String) ToTable(String) ToTable(String)

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

public:
 System::Data::DataTable ^ ToTable(System::String ^ tableName);
public System.Data.DataTable ToTable (string tableName);
member this.ToTable : string -> System.Data.DataTable
Public Function ToTable (tableName As String) As DataTable

Параметры

tableName
String String String String

Имя возвращенного объекта DataTable.The name of the returned DataTable.

Возвраты

Новый экземпляр класса DataTable, который содержит запрошенные строки и столбцы.A new DataTable instance that contains the requested rows and columns.

Примеры

В следующем образце консольного приложения создает DataTable, заполняет DataTable с данными, создает отфильтрованное представление, в зависимости от исходных данных и наконец DataTable с новым именем, который содержит отфильтрованные строки.The following console application example creates a DataTable, fills the DataTable with data, creates a filtered view based on the original data, and finally creates a DataTable with a new name that contains the filtered rows.

private static void DemonstrateDataView()
{
    // Create a DataTable with three columns.
    DataTable table = new DataTable("NewTable");
    Console.WriteLine("Original table name: " + table.TableName);
    DataColumn column = new DataColumn("ID", typeof(System.Int32));
    table.Columns.Add(column);

    column = new DataColumn("Category", typeof(System.String));
    table.Columns.Add(column);

    column = new DataColumn("Product", typeof(System.String));
    table.Columns.Add(column);

    column = new DataColumn("QuantityInStock", typeof(System.Int32));
    table.Columns.Add(column);


    // Add some items.
    DataRow row = table.NewRow();
    row.ItemArray = new object[] { 1, "Fruit", "Apple", 14 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 2, "Fruit", "Orange", 27 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 3, "Bread", "Muffin", 23 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 4, "Fish", "Salmon", 12 };
    table.Rows.Add(row);

    // Mark all rows as "accepted". Not really required
    // for this particular example.
    table.AcceptChanges();

    // Print current table values.
    PrintTableOrView(table, "Current Values in Table");

    DataView view = new DataView(table);
    view.RowFilter = "QuantityInStock > 15";
    PrintTableOrView(view, "Current Values in View");

    DataTable newTable = view.ToTable("FilteredTable");
    PrintTableOrView(newTable, "Table created from filtered DataView");
    Console.WriteLine("New table name: " + newTable.TableName);

    Console.WriteLine("Press any key to continue.");
    Console.ReadKey();
}

private static void PrintTableOrView(DataView dv, string label)
{
    System.IO.StringWriter sw;
    string output;
    DataTable table = dv.Table;

    Console.WriteLine(label);

    // Loop through each row in the view.
    foreach (DataRowView rowView in dv)
    {
        sw = new System.IO.StringWriter();

        // Loop through each column.
        foreach (DataColumn col in table.Columns)
        {
            // Output the value of each column's data.
            sw.Write(rowView[col.ColumnName].ToString() + ", ");
        }
        output = sw.ToString();
        // Trim off the trailing ", ", so the output looks correct.
        if (output.Length > 2)
        {
            output = output.Substring(0, output.Length - 2);
        }
        // Display the row in the console window.
        Console.WriteLine(output);
    }
    Console.WriteLine();
}

private static void PrintTableOrView(DataTable table, string label)
{
    System.IO.StringWriter sw;
    string output;

    Console.WriteLine(label);

    // Loop through each row in the table.
    foreach (DataRow row in table.Rows)
    {
        sw = new System.IO.StringWriter();
        // Loop through each column.
        foreach (DataColumn col in table.Columns)
        {
            // Output the value of each column's data.
            sw.Write(row[col].ToString() + ", ");
        }
        output = sw.ToString();
        // Trim off the trailing ", ", so the output looks correct.
        if (output.Length > 2)
        {
            output = output.Substring(0, output.Length - 2);
        }
        // Display the row in the console window.
        Console.WriteLine(output);
    } //
    Console.WriteLine();
}
Private Sub DemonstrateDataView()
    ' Create a DataTable with three columns.
    Dim table As DataTable = New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As DataColumn = New DataColumn("ID", GetType(System.Int32))
    table.Columns.Add(column)

    column = New DataColumn("Category", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("Product", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("QuantityInStock", GetType(System.Int32))
    table.Columns.Add(column)


    ' Add some items.
    Dim row As DataRow = table.NewRow()
    row.ItemArray = New Object() {1, "Fruit", "Apple", 14}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {2, "Fruit", "Orange", 27}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {3, "Bread", "Muffin", 23}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {4, "Fish", "Salmon", 12}
    table.Rows.Add(row)

    ' Mark all rows as "accepted". Not required
    ' for this particular example.
    table.AcceptChanges()

    ' Print current table values.
    PrintTableOrView(table, "Current Values in Table")

    Dim view As DataView = New DataView(table)
    view.RowFilter = "QuantityInStock > 15"
    PrintTableOrView(view, "Current Values in View")

    Dim newTable As DataTable = view.ToTable("FilteredTable")
    PrintTableOrView(newTable, "Table created from filtered DataView")
    Console.WriteLine("New table name: " & newTable.TableName)

    Console.WriteLine("Press any key to continue.")
    Console.ReadKey()
End Sub

Private Sub PrintTableOrView(ByVal dv As DataView, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String
    Dim table As DataTable = dv.Table

    Console.WriteLine(label)

    ' Loop through each row in the view.
    For Each rowView As DataRowView In dv
        sw = New System.IO.StringWriter

        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(rowView(col.ColumnName).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

Private Sub PrintTableOrView(ByVal table As DataTable, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String

    Console.WriteLine(label)

    ' Loop through each row in the table.
    For Each row As DataRow In table.Rows
        sw = New System.IO.StringWriter
        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(row(col).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

В этом примере отображается следующий текст в окне консоли:The example displays the following text in the console window:

Original table name: NewTable  
Current Values in Table  
1, Fruit, Apple, 14  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  
4, Fish, Salmon, 12  

Current Values in View  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  

Table created from filtered DataView  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  

New table name: FilteredTable  

Комментарии

Так как этот метод не позволяет указать лишь часть доступных столбцов, выходная таблица содержит те же столбцы, что входная таблица.Because this method does not let you specify a subset of available columns, the output table contains the same columns as the input table.

Дополнительно

ToTable(String, Boolean, String[]) ToTable(String, Boolean, String[]) ToTable(String, Boolean, String[]) ToTable(String, Boolean, String[])

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

public:
 System::Data::DataTable ^ ToTable(System::String ^ tableName, bool distinct, ... cli::array <System::String ^> ^ columnNames);
public System.Data.DataTable ToTable (string tableName, bool distinct, params string[] columnNames);
member this.ToTable : string * bool * string[] -> System.Data.DataTable
Public Function ToTable (tableName As String, distinct As Boolean, ParamArray columnNames As String()) As DataTable

Параметры

tableName
String String String String

Имя возвращенного объекта DataTable.The name of the returned DataTable.

distinct
Boolean Boolean Boolean Boolean

При значении true возвращенный объект DataTable содержит строки с различными значениями для всех столбцов.If true, the returned DataTable contains rows that have distinct values for all its columns. Значение по умолчанию — false.The default value is false.

columnNames
String[]

Массив строк, содержащий список имен столбцов, которые должны быть включены в возвращенный объект DataTable.A string array that contains a list of the column names to be included in the returned DataTable. Объект DataTable, содержащий указанные столбцы в том порядке, в каком они отображаются внутри массива.The DataTable contains the specified columns in the order they appear within this array.

Возвраты

Новый экземпляр класса DataTable, который содержит запрошенные строки и столбцы.A new DataTable instance that contains the requested rows and columns.

Примеры

В следующем образце консольного приложения создает DataTable, заполняет DataTable с данными, сортирует DataViewи наконец создает DataTable с новым именем, который содержит только два столбца, ограниченное строками, в которых все значения являются уникальными.The following console application example creates a DataTable, fills the DataTable with data, sorts the DataView, and finally creates a DataTable with a new name that contains just two columns, limited to rows in which all values are unique.

private static void DemonstrateDataView()
{
    // Create a DataTable with three columns.
    DataTable table = new DataTable("NewTable");
    Console.WriteLine("Original table name: " + table.TableName);
    DataColumn column = new DataColumn("ID", typeof(System.Int32));
    table.Columns.Add(column);

    column = new DataColumn("Category", typeof(System.String));
    table.Columns.Add(column);

    column = new DataColumn("Product", typeof(System.String));
    table.Columns.Add(column);

    column = new DataColumn("QuantityInStock", typeof(System.Int32));
    table.Columns.Add(column);

    // Add some items.
    DataRow row = table.NewRow();
    row.ItemArray = new object[] { 1, "Fruit", "Apple", 14 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 2, "Fruit", "Orange", 27 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 3, "Bread", "Muffin", 23 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 4, "Fish", "Salmon", 12 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 5, "Fish", "Salmon", 15 };
    table.Rows.Add(row);

    row = table.NewRow();
    row.ItemArray = new object[] { 6, "Bread", "Croissant", 23};
    table.Rows.Add(row);

    // Mark all rows as "accepted". Not required
    // for this particular example.
    table.AcceptChanges();

    // Print current table values.
    PrintTableOrView(table, "Current Values in Table");

    DataView view = new DataView(table);
    view.Sort = "Category";
    PrintTableOrView(view, "Current Values in View");

    DataTable newTable = view.ToTable("UniqueData", true, 
        "Category", "QuantityInStock");
    PrintTableOrView(newTable, "Table created from sorted DataView");
    Console.WriteLine("New table name: " + newTable.TableName);

    Console.WriteLine("Press any key to continue.");
    Console.ReadKey();
}

private static void PrintTableOrView(DataView dv, string label)
{
    System.IO.StringWriter sw;
    string output;
    DataTable table = dv.Table;

    Console.WriteLine(label);

    // Loop through each row in the view.
    foreach (DataRowView rowView in dv)
    {
        sw = new System.IO.StringWriter();

        // Loop through each column.
        foreach (DataColumn col in table.Columns)
        {
            // Output the value of each column's data.
            sw.Write(rowView[col.ColumnName].ToString() + ", ");
        }
        output = sw.ToString();
        // Trim off the trailing ", ", so the output looks correct.
        if (output.Length > 2)
        {
            output = output.Substring(0, output.Length - 2);
        }
        // Display the row in the console window.
        Console.WriteLine(output);
    }
    Console.WriteLine();
}

private static void PrintTableOrView(DataTable table, string label)
{
    System.IO.StringWriter sw;
    string output;

    Console.WriteLine(label);

    // Loop through each row in the table.
    foreach (DataRow row in table.Rows)
    {
        sw = new System.IO.StringWriter();
        // Loop through each column.
        foreach (DataColumn col in table.Columns)
        {
            // Output the value of each column's data.
            sw.Write(row[col].ToString() + ", ");
        }
        output = sw.ToString();
        // Trim off the trailing ", ", so the output looks correct.
        if (output.Length > 2)
        {
            output = output.Substring(0, output.Length - 2);
        }
        // Display the row in the console window.
        Console.WriteLine(output);
    } //
    Console.WriteLine();
}
Private Sub DemonstrateDataView()
    ' Create a DataTable with three columns.
    Dim table As DataTable = New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As DataColumn = New DataColumn("ID", GetType(System.Int32))
    table.Columns.Add(column)

    column = New DataColumn("Category", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("Product", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("QuantityInStock", GetType(System.Int32))
    table.Columns.Add(column)


    ' Add some items.
    Dim row As DataRow = table.NewRow()
    row.ItemArray = New Object() {1, "Fruit", "Apple", 14}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {2, "Fruit", "Orange", 27}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {3, "Bread", "Muffin", 23}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {4, "Fish", "Salmon", 12}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {5, "Fish", "Salmon", 15}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {6, "Bread", "Croissant", 23}
    table.Rows.Add(row)

    ' Mark all rows as "accepted". Not required
    ' for this particular example.
    table.AcceptChanges()

    ' Print current table values.
    PrintTableOrView(table, "Current Values in Table")

    Dim view As DataView = New DataView(table)
    view.Sort = "Category"
    PrintTableOrView(view, "Current Values in View")

    Dim newTable As DataTable = view.ToTable("UniqueData", _
        True, "Category", "QuantityInStock")
    PrintTableOrView(newTable, "Table created from sorted DataView")
    Console.WriteLine("New table name: " & newTable.TableName)

    Console.WriteLine("Press any key to continue.")
    Console.ReadKey()
End Sub

Private Sub PrintTableOrView(ByVal dv As DataView, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String
    Dim table As DataTable = dv.Table

    Console.WriteLine(label)

    ' Loop through each row in the view.
    For Each rowView As DataRowView In dv
        sw = New System.IO.StringWriter

        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(rowView(col.ColumnName).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

Private Sub PrintTableOrView(ByVal table As DataTable, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String

    Console.WriteLine(label)

    ' Loop through each row in the table.
    For Each row As DataRow In table.Rows
        sw = New System.IO.StringWriter
        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(row(col).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

В этом примере в окне консоли отображаются следующие выходные данные:The example displays the following output in the console window:

Original table name: NewTable  
Current Values in Table  
1, Fruit, Apple, 14  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  
4, Fish, Salmon, 12  
5, Fish, Salmon, 15  
6, Bread, Croissant, 23  

Current Values in View  
3, Bread, Muffin, 23  
6, Bread, Croissant, 23  
4, Fish, Salmon, 12  
5, Fish, Salmon, 15  
1, Fruit, Apple, 14  
2, Fruit, Orange, 27  

Table created from sorted DataView  
Bread, 23  
Fish, 12  
Fish, 15  
Fruit, 14  
Fruit, 27  

New table name: UniqueData  

Комментарии

Используйте этот перегруженную версию ToTable метод, если нужно извлечь различающихся значений в подмножество доступных столбцов, указав новое имя для возвращенного DataTable.Use this overloaded version of the ToTable method if you have to retrieve distinct values in a subset of available columns, specifying a new name for the returned DataTable. Если не требуется отдельных строк или подмножество столбцов, см. в разделе ToTable.If you do not need distinct rows or a subset of columns, see ToTable.

Дополнительно

ToTable() ToTable() ToTable() ToTable()

Создает и возвращает новый объект DataTable на основе строк в существующем объекте DataView.Creates and returns a new DataTable based on rows in an existing DataView.

public:
 System::Data::DataTable ^ ToTable();
public System.Data.DataTable ToTable ();
member this.ToTable : unit -> System.Data.DataTable
Public Function ToTable () As DataTable

Возвраты

Новый экземпляр класса DataTable, который содержит запрошенные строки и столбцы.A new DataTable instance that contains the requested rows and columns.

Примеры

В следующем образце консольного приложения создает DataTable, заполняет DataTable с данными, создает отфильтрованное представление, в зависимости от исходных данных и наконец, DataTable , содержащий отфильтрованные строки.The following console application example creates a DataTable, fills the DataTable with data, creates a filtered view based on the original data, and finally, creates a DataTable that contains the filtered rows.

using System;
using System.Data;

class Program {
    static void Main() {
        DemonstrateDataView();
    }

    private static void DemonstrateDataView() {
        // Create a DataTable with three columns.
        DataTable table = new DataTable("NewTable");
        Console.WriteLine("Original table name: " + table.TableName);
        DataColumn column = new DataColumn("ID", typeof(System.Int32));
        table.Columns.Add(column);

        column = new DataColumn("Category", typeof(System.String));
        table.Columns.Add(column);

        column = new DataColumn("Product", typeof(System.String));
        table.Columns.Add(column);

        column = new DataColumn("QuantityInStock", typeof(System.Int32));
        table.Columns.Add(column);


        // Add some items.
        DataRow row = table.NewRow();
        row.ItemArray = new object[] { 1, "Fruit", "Apple", 14 };
        table.Rows.Add(row);

        row = table.NewRow();
        row.ItemArray = new object[] { 2, "Fruit", "Orange", 27 };
        table.Rows.Add(row);

        row = table.NewRow();
        row.ItemArray = new object[] { 3, "Bread", "Muffin", 23 };
        table.Rows.Add(row);

        row = table.NewRow();
        row.ItemArray = new object[] { 4, "Fish", "Salmon", 12 };
        table.Rows.Add(row);

        // Mark all rows as "accepted". Not really required
        // for this particular example.
        table.AcceptChanges();

        // Print current table values.
        PrintTableOrView(table, "Current Values in Table");

        DataView view = new DataView(table);
        view.RowFilter = "QuantityInStock > 15";
        PrintTableOrView(view, "Current Values in View");

        DataTable newTable = view.ToTable();
        PrintTableOrView(newTable, "Table created from filtered DataView");
        Console.WriteLine("New table name: " + newTable.TableName);

        Console.WriteLine("Press any key to continue.");
        Console.ReadKey();
    }

    private static void PrintTableOrView(DataView dv, string label) {
        System.IO.StringWriter sw;
        string output;
        DataTable table = dv.Table;

        Console.WriteLine(label);

        // Loop through each row in the view.
        foreach (DataRowView rowView in dv) {
            sw = new System.IO.StringWriter();

            // Loop through each column.
            foreach (DataColumn col in table.Columns) {
                // Output the value of each column's data.
                sw.Write(rowView[col.ColumnName].ToString() + ", ");
            }

            output = sw.ToString();

            // Trim off the trailing ", ", so the output looks correct.
            if (output.Length > 2)
                output = output.Substring(0, output.Length - 2);

            // Display the row in the console window.
            Console.WriteLine(output);
        }
        Console.WriteLine();
    }

    private static void PrintTableOrView(DataTable table, string label) {
        System.IO.StringWriter sw;
        string output;

        Console.WriteLine(label);

        // Loop through each row in the table.
        foreach (DataRow row in table.Rows) {
            sw = new System.IO.StringWriter();

            // Loop through each column.
            foreach (DataColumn col in table.Columns) {
                // Output the value of each column's data.
                sw.Write(row[col].ToString() + ", ");
            }

            output = sw.ToString();

            // Trim off the trailing ", ", so the output looks correct.
            if (output.Length > 2)
                output = output.Substring(0, output.Length - 2);

            // Display the row in the console window.
            Console.WriteLine(output);
        }
        Console.WriteLine();
    }
}
Private Sub DemonstrateDataView()
    ' Create a DataTable with three columns.
    Dim table As DataTable = New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As DataColumn = New DataColumn("ID", GetType(System.Int32))
    table.Columns.Add(column)

    column = New DataColumn("Category", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("Product", GetType(System.String))
    table.Columns.Add(column)

    column = New DataColumn("QuantityInStock", GetType(System.Int32))
    table.Columns.Add(column)

    ' Add some items.
    Dim row As DataRow = table.NewRow()
    row.ItemArray = New Object() {1, "Fruit", "Apple", 14}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {2, "Fruit", "Orange", 27}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {3, "Bread", "Muffin", 23}
    table.Rows.Add(row)

    row = table.NewRow()
    row.ItemArray = New Object() {4, "Fish", "Salmon", 12}
    table.Rows.Add(row)

    ' Mark all rows as "accepted". Not required
    ' for this particular example.
    table.AcceptChanges()

    ' Print current table values.
    PrintTableOrView(table, "Current Values in Table")

    Dim view As DataView = New DataView(table)
    view.RowFilter = "QuantityInStock > 15"
    PrintTableOrView(view, "Current Values in View")

    Dim newTable As DataTable = view.ToTable()
    PrintTableOrView(newTable, "Table created from filtered DataView")
    Console.WriteLine("New table name: " & newTable.TableName)

    Console.WriteLine("Press any key to continue.")
    Console.ReadKey()
End Sub

Private Sub PrintTableOrView(ByVal dv As DataView, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String
    Dim table As DataTable = dv.Table

    Console.WriteLine(label)

    ' Loop through each row in the view.
    For Each rowView As DataRowView In dv
        sw = New System.IO.StringWriter

        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(rowView(col.ColumnName).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

Private Sub PrintTableOrView(ByVal table As DataTable, ByVal label As String)
    Dim sw As System.IO.StringWriter
    Dim output As String

    Console.WriteLine(label)

    ' Loop through each row in the table.
    For Each row As DataRow In table.Rows
        sw = New System.IO.StringWriter
        ' Loop through each column.
        For Each col As DataColumn In table.Columns
            ' Output the value of each column's data.
            sw.Write(row(col).ToString() & ", ")
        Next
        output = sw.ToString
        ' Trim off the trailing ", ", so the output looks correct.
        If output.Length > 2 Then
            output = output.Substring(0, output.Length - 2)
        End If
        ' Display the row in the console window.
        Console.WriteLine(output)
    Next
    Console.WriteLine()
End Sub

В этом примере отображается следующий текст в окне консоли:The example displays the following text in the console window:

Original table name: NewTable  
Current Values in Table  
1, Fruit, Apple, 14  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  
4, Fish, Salmon, 12  

Current Values in View  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  

Table created from filtered DataView  
2, Fruit, Orange, 27  
3, Bread, Muffin, 23  

New table name: NewTable  

Комментарии

Так как этот метод не позволяет указать имя для выходных данных DataTable, его имя совпадает с именем источника DataTable.Because this method does not let you specify the name for the output DataTable, its name is the same as the name of the source DataTable. Так как этот метод не позволяет указать лишь часть доступных столбцов, выходная таблица содержит те же столбцы, что входная таблица.Because this method does not let you specify a subset of available columns, the output table contains the same columns as the input table.

Дополнительно

Применяется к