DataView.ToTable 方法

定义

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates and returns a new DataTable based on rows in an existing DataView.

重载

ToTable(Boolean, String[])

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates and returns a new DataTable based on rows in an existing DataView.

ToTable(String)

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates and returns a new DataTable based on rows in an existing DataView.

ToTable(String, Boolean, String[])

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates and returns a new DataTable based on rows in an existing DataView.

ToTable()

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates and returns a new DataTable based on rows in an existing DataView.

注解

返回 DataTable 维护源 DataTable中以下属性的值: NamespacePrefixLocaleCaseSensitiveThe returned DataTable maintains the values of the following properties from the source DataTable: Namespace, Prefix, Locale, and CaseSensitive. 所得 DataTable 中的每一列都包含基础 DataTable中所有对应属性的相同副本。Each column in the resulting DataTable contains an identical copy of all the corresponding properties in the underlying DataTable.

返回的 DataTable 中的 DataRow 实例将包含与 CLR 语义一致的值。The DataRow instances in the returned DataTable will contain values that are consistent with CLR semantics. 也就是说,对于除用户定义类型之外的所有数据类型,将按值复制相应的列值。That is, for all data types besides user-defined types, the corresponding column values are copied by value. 对于用户定义的数据类型,列数据按引用进行复制。For user-defined data types, the column data is copied by reference.

ToTable(Boolean, String[])

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates 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

参数

distinct
Boolean

如果为 true,则返回的 DataTable 包含具有与其所有列不同的值的行。If true, the returned DataTable contains rows that have distinct values for all its columns. 默认值为 falseThe default value is false.

columnNames
String[]

一个字符串数组,其中的一个列名称列表将包括在返回的 DataTable 中。A string array that contains a list of the column names to be included in the returned DataTable. DataTable 包含指定的列,这些列按其在该数组中显示的顺序排列。The DataTable contains the specified columns in the order they appear within this array.

返回

一个新 DataTable 实例,其中包含请求的行和列。A new DataTable instance that contains the requested rows and columns.

示例

下面的控制台应用程序示例创建一个 DataTable,使用数据填充 DataTable,对 DataView进行排序,最后创建一个只包含两列的 DataTable,其中所有值都是唯一的。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 New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As 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 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

该示例在控制台窗口中显示以下输出: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  

注解

由于此方法不允许指定输出 DataTable的名称,因此其名称与源 DataTable的名称相同。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)

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates 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

参数

tableName
String

返回的 DataTable 的名称。The name of the returned DataTable.

返回

一个新 DataTable 实例,其中包含请求的行和列。A new DataTable instance that contains the requested rows and columns.

示例

下面的控制台应用程序示例创建一个 DataTable,使用数据填充 DataTable,基于原始数据创建筛选视图,最后创建一个 DataTable,其中包含已筛选行的新名称。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 New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As 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 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

该示例在控制台窗口中显示以下文本: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  

注解

由于此方法不允许您指定可用列的子集,因此输出表包含与输入表相同的列。Because this method does not let you specify a subset of available columns, the output table contains the same columns as the input table.

另请参阅

ToTable(String, Boolean, String[])

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates 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

参数

tableName
String

返回的 DataTable 的名称。The name of the returned DataTable.

distinct
Boolean

如果为 true,则返回的 DataTable 包含具有与其所有列不同的值的行。If true, the returned DataTable contains rows that have distinct values for all its columns. 默认值为 falseThe default value is false.

columnNames
String[]

一个字符串数组,其中的一个列名称列表将包括在返回的 DataTable 中。A string array that contains a list of the column names to be included in the returned DataTable. DataTable 包含指定的列,这些列按其在该数组中显示的顺序排列。The DataTable contains the specified columns in the order they appear within this array.

返回

一个新 DataTable 实例,其中包含请求的行和列。A new DataTable instance that contains the requested rows and columns.

示例

下面的控制台应用程序示例创建一个 DataTable,使用数据填充 DataTable,对 DataView进行排序,最后创建一个 DataTable,其中包含只包含两个列的新名称,这些行仅限所有值都是唯一的。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 New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As 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 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

该示例在控制台窗口中显示以下输出: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  

注解

如果必须检索可用列的子集中的非重复值,请使用此重载版本的 ToTable 方法,并为返回的 DataTable指定新名称。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. 如果不需要非重复行或列的子集,请参阅 ToTableIf you do not need distinct rows or a subset of columns, see ToTable.

另请参阅

ToTable()

基于现有的 DataTable 中的行,创建并返回一个新的 DataViewCreates 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

返回

一个新 DataTable 实例,其中包含请求的行和列。A new DataTable instance that contains the requested rows and columns.

示例

下面的控制台应用程序示例创建一个 DataTable,使用数据填充 DataTable,基于原始数据创建筛选视图,最后创建一个包含筛选行的 DataTableThe 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 New DataTable("NewTable")
    Console.WriteLine("Original table name: " & table.TableName)
    Dim column As 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 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

该示例在控制台窗口中显示以下文本: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  

注解

由于此方法不允许指定输出 DataTable的名称,因此其名称与源 DataTable的名称相同。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. 由于此方法不允许您指定可用列的子集,因此输出表包含与输入表相同的列。Because this method does not let you specify a subset of available columns, the output table contains the same columns as the input table.

另请参阅

适用于