BindingContext.Item[] 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

取得 BindingManagerBase。

多載

Item[Object, String]	取得與指定之資料來源和資料成員相關的 BindingManagerBase。
Item[Object]	取得與指定之資料來源相關的 BindingManagerBase。

Item[Object, String]

取得與指定之資料來源和資料成員相關的 BindingManagerBase。

public:
 property System::Windows::Forms::BindingManagerBase ^ default[System::Object ^, System::String ^] { System::Windows::Forms::BindingManagerBase ^ get(System::Object ^ dataSource, System::String ^ dataMember); };

public System.Windows.Forms.BindingManagerBase this[object dataSource, string? dataMember] { get; }

member this.Item(obj * string) : System.Windows.Forms.BindingManagerBase

Default Public ReadOnly Property Item(dataSource As Object, dataMember As String) As BindingManagerBase

參數

dataSource

Object

與特定 BindingManagerBase 相關的資料來源。

dataMember

String

巡覽路徑，包含解析至特定 BindingManagerBase 的資訊。

屬性值

BindingManagerBase

指定之資料來源和資料成員的 BindingManagerBase。

例外狀況

Exception

指定的 dataMember 不存在於資料來源中。

範例

下列程式碼範例示範如何使用 Item[] 來擷取 BindingManagerBase 特定系結的 。 它也會示範如何處理 BindingCompleteBindingManagerBase 的事件，以確保當其中一個控制項值變更時，系結至相同資料來源的多個控制項仍保持同步。 若要執行此範例，請將程式碼貼到 Windows Form 中，並從表單的建構函式或 Load 事件處理方法呼叫 InitializeControlsAndData 方法。

private void InitializeControlsAndData()
{
    // Initialize the controls and set location, size and 
    // other basic properties.
    this.dataGridView1 = new DataGridView();
    
    this.textBox1 = new TextBox();
    this.textBox2 = new TextBox();
    this.dataGridView1.ColumnHeadersHeightSizeMode =
        DataGridViewColumnHeadersHeightSizeMode.AutoSize;
    this.dataGridView1.Dock = DockStyle.Top;
    this.dataGridView1.Location = new Point(0, 0);
    this.dataGridView1.Size = new Size(292, 150);
    this.textBox1.Location = new Point(132, 156);
    this.textBox1.Size = new Size(100, 20);
    this.textBox2.Location = new Point(12, 156);
    this.textBox2.Size = new Size(100, 20);
    this.ClientSize = new Size(292, 266);
    this.Controls.Add(this.textBox2);
    this.Controls.Add(this.textBox1);
    this.Controls.Add(this.dataGridView1);

    // Declare the DataSet and add a table and column.
    DataSet set1 = new DataSet();
    set1.Tables.Add("Menu");
    set1.Tables[0].Columns.Add("Beverages");

    // Add some rows to the table.
    set1.Tables[0].Rows.Add("coffee");
    set1.Tables[0].Rows.Add("tea");
    set1.Tables[0].Rows.Add("hot chocolate");
    set1.Tables[0].Rows.Add("milk");
    set1.Tables[0].Rows.Add("orange juice");

    // Add the control data bindings.
    dataGridView1.DataSource = set1;
    dataGridView1.DataMember = "Menu";
    textBox1.DataBindings.Add("Text", set1,
        "Menu.Beverages", true, DataSourceUpdateMode.OnPropertyChanged);
    textBox2.DataBindings.Add("Text", set1,
        "Menu.Beverages", true, DataSourceUpdateMode.OnPropertyChanged);

    BindingManagerBase bmb = this.BindingContext[set1, "Menu"];
    bmb.BindingComplete += new BindingCompleteEventHandler(bmb_BindingComplete);
}

private void bmb_BindingComplete(object sender, BindingCompleteEventArgs e)
{
    // Check if the data source has been updated, and that no error has occurred.
    if (e.BindingCompleteContext ==
        BindingCompleteContext.DataSourceUpdate && e.Exception == null)

        // If not, end the current edit.
        e.Binding.BindingManagerBase.EndCurrentEdit(); ;
}

Dim WithEvents bmb As BindingManagerBase

Private Sub InitializeControlsAndData() 
    ' Initialize the controls and set location, size and 
    ' other basic properties.
    Me.dataGridView1 = New DataGridView()
    
    Me.textBox1 = New TextBox()
    Me.textBox2 = New TextBox()
    Me.dataGridView1.ColumnHeadersHeightSizeMode = _
        DataGridViewColumnHeadersHeightSizeMode.AutoSize
    Me.dataGridView1.Dock = DockStyle.Top
    Me.dataGridView1.Location = New Point(0, 0)
    Me.dataGridView1.Size = New Size(292, 150)
    Me.textBox1.Location = New Point(132, 156)
    Me.textBox1.Size = New Size(100, 20)
    Me.textBox2.Location = New Point(12, 156)
    Me.textBox2.Size = New Size(100, 20)
    Me.ClientSize = New Size(292, 266)
    Me.Controls.Add(Me.textBox2)
    Me.Controls.Add(Me.textBox1)
    Me.Controls.Add(Me.dataGridView1)
    
    ' Declare the DataSet and add a table and column.
    Dim set1 As New DataSet()
    set1.Tables.Add("Menu")
    set1.Tables(0).Columns.Add("Beverages")
    
    ' Add some rows to the table.
    set1.Tables(0).Rows.Add("coffee")
    set1.Tables(0).Rows.Add("tea")
    set1.Tables(0).Rows.Add("hot chocolate")
    set1.Tables(0).Rows.Add("milk")
    set1.Tables(0).Rows.Add("orange juice")

    ' Add the control data bindings.
    dataGridView1.DataSource = set1
    dataGridView1.DataMember = "Menu"
    textBox1.DataBindings.Add("Text", set1, "Menu.Beverages", _
        True, DataSourceUpdateMode.OnPropertyChanged)
    textBox2.DataBindings.Add("Text", set1, "Menu.Beverages", _
        True, DataSourceUpdateMode.OnPropertyChanged)

    ' Get the BindingManagerBase for this binding.
    bmb = Me.BindingContext(set1, "Menu")

End Sub

Private Sub bmb_BindingComplete(ByVal sender As Object, ByVal e As BindingCompleteEventArgs) _
    Handles bmb.BindingComplete

    ' Check if the data source has been updated, and that no error has occurred.
    If e.BindingCompleteContext = BindingCompleteContext.DataSourceUpdate _
        AndAlso e.Exception Is Nothing Then

        ' If not, end the current edit.
        e.Binding.BindingManagerBase.EndCurrentEdit()
    End If
End Sub

備註

當 管理資料來源包含多個物件的一組 Binding 物件時 BindingManagerBase ，請使用這個多載。 例如， DataSet 可以包含由 物件連結的 DataRelation 數個 DataTable 物件。 在這種情況下，必須有導覽路徑，才能讓 BindingContext 傳回正確的 BindingManagerBase 。

注意

當 參數有效時，屬性 Item[] 一律會傳回 BindingManagerBase 。 dataMember 它永遠不會傳回 null 。

Binding如需有關建立控制項與資料來源之間系結的資訊，請參閱 類別以取得可能資料來源的清單。

如果想要 BindingManagerBase 管理清單，流覽路徑也必須以清單結尾。 例如，下列 C# 程式碼會將 TextBox 控制項系結至訂單資料表中的訂單日期。 流覽路徑包括 TableName 、 RelationName 、 和 ColumnName 。 不過， BindingManagerBase 只能使用 TableName 解析為清單) 的 和 RelationName (來擷取 。

// The navigation path for a Binding ends with a property.  
textBox1.DataBindings.Add  
("Text", dataSet1, "Customers.custToOrders.OrderDate");  
// The navigation path for the BindingManagerBase ends with a list.  
BindingManagerBase bmOrders = this.BindingContext  
[dataSet1, "Customers.custToOrders"];  

傳 BindingManagerBase 回 時，您應該使用與 相同的資料來源 Binding ，並只修改流覽路徑。

Contains使用 方法來判斷所需的 BindingManagerBase 是否已存在。

另請參閱

• BindingsCollection
• Binding

Item[Object]

取得與指定之資料來源相關的 BindingManagerBase。

public:
 property System::Windows::Forms::BindingManagerBase ^ default[System::Object ^] { System::Windows::Forms::BindingManagerBase ^ get(System::Object ^ dataSource); };

public System.Windows.Forms.BindingManagerBase this[object dataSource] { get; }

member this.Item(obj) : System.Windows.Forms.BindingManagerBase

Default Public ReadOnly Property Item(dataSource As Object) As BindingManagerBase

參數

dataSource

Object

與特定 BindingManagerBase 相關的資料來源。

屬性值

BindingManagerBase

指定之資料來源的 BindingManagerBase。

範例

下列程式碼範例會傳回三 BindingManagerBase 個 DataView 物件：一個用於 、一 ArrayList 個用於 ，另一個用於 DataSource 屬於 TextBox 控制項的 Binding 。

void ReturnBindingManagerBase()
{
   
   // Get the BindingManagerBase for a DataView. 
   BindingManagerBase^ bmCustomers = this->BindingContext[ myDataView ];
   
   /* Get the BindingManagerBase for an ArrayList. */
   BindingManagerBase^ bmOrders = this->BindingContext[ myArrayList ];
   
   // Get the BindingManagerBase for a TextBox control.
   BindingManagerBase^ baseArray = this->BindingContext[ textBox1->DataBindings[ nullptr ]->DataSource ];
}

private void ReturnBindingManagerBase()
{
   // Get the BindingManagerBase for a DataView. 
   BindingManagerBase bmCustomers = 
   this.BindingContext [myDataView];

   /* Get the BindingManagerBase for an ArrayList. */ 
   BindingManagerBase bmOrders = 
   this.BindingContext[myArrayList];

   // Get the BindingManagerBase for a TextBox control.
   BindingManagerBase baseArray = 
   this.BindingContext[textBox1.DataBindings[0].DataSource];
}

Private Sub ReturnBindingManagerBase()
   ' Get the BindingManagerBase for a DataView. 
   Dim bmCustomers As BindingManagerBase = _
      Me.BindingContext(myDataView)

   ' Get the BindingManagerBase for an ArrayList.
   Dim bmOrders As BindingManagerBase = _
      Me.BindingContext(myArrayList)

   ' Get the BindingManagerBase for a TextBox control.
   Dim baseArray As BindingManagerBase = _
      Me.BindingContext(Text1.DataBindings(0).DataSource)
End Sub

備註

如果您想要不需要流覽路徑， BindingManagerBase 請使用此多載。 例如，如果 BindingManagerBase 會管理一組 Binding 使用 ArrayList 或 DataTable 做為 DataSource 的物件，則不需要流覽路徑。

注意

屬性 Item[] 一律會傳回 BindingManagerBase ，且永遠不會傳回 null 。

Binding如需有關建立控制項與資料來源之間系結的資訊，請參閱 類別以取得可能資料來源的清單。

另請參閱

• BindingsCollection
• Binding