共用方式為

如何：確保繫結至相同資料來源的多個控制項都能保持同步

  • 發行項

在 Windows Forms 中使用資料繫結時，通常會將多個控制項繫結至相同的資料來源。 在某些情況下，可能需要採取額外的步驟，以確保控制項的繫結屬性在彼此和與資料來源之間保持同步。 在兩種情況下，這些步驟是必要的：

在先前的案例中，您可以使用 BindingSource 將資料來源繫結至控制項。 在後者的情況下，您會使用 BindingSource 並處理 BindingComplete 事件，並在相關聯的 BindingManagerBase 上呼叫 EndCurrentEdit。

範例

下列程式碼範例示範如何使用 BindingSource 元件，將三個控制項 (兩個文字方塊控制項和 DataGridView 控制項) 繫結至 DataSet 中的相同資料行。 這個範例示範如何處理 BindingComplete 事件，並確保當一個文字方塊的文字值變更時，其他文字方塊和 DataGridView 控制項會以正確的值更新。

此範例會使用 BindingSource 來繫結資料來源和控制項。 或者，您可以將控制項直接繫結至資料來源，並從表單的 BindingContext 擷取繫結的 BindingManagerBase，然後處理 BindingManagerBase 的 BindingComplete 事件。 如需如何執行這項操作的範例，請參閱關於 BindingManagerBase 之 BindingComplete 事件的說明頁面。


// Declare the controls to be used.
private BindingSource bindingSource1;
private TextBox textBox1;
private TextBox textBox2;
private DataGridView dataGridView1;

private void InitializeControlsAndDataSource()
{
    // Initialize the controls and set location, size and
    // other basic properties.
    this.dataGridView1 = new DataGridView();
    this.bindingSource1 = new BindingSource();
    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");

    // Set the data source to the DataSet.
    bindingSource1.DataSource = set1;

    //Set the DataMember to the Menu table.
    bindingSource1.DataMember = "Menu";

    // Add the control data bindings.
    dataGridView1.DataSource = bindingSource1;
    textBox1.DataBindings.Add("Text", bindingSource1,
        "Beverages", true, DataSourceUpdateMode.OnPropertyChanged);
    textBox2.DataBindings.Add("Text", bindingSource1,
        "Beverages", true, DataSourceUpdateMode.OnPropertyChanged);
    bindingSource1.BindingComplete +=
        new BindingCompleteEventHandler(bindingSource1_BindingComplete);
}

private void bindingSource1_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();
}


' Declare the controls to be used.
Private WithEvents bindingSource1 As BindingSource
Private WithEvents textBox1 As TextBox
Private WithEvents textBox2 As TextBox
Private WithEvents dataGridView1 As DataGridView


Private Sub InitializeControlsAndDataSource() 
    ' Initialize the controls and set location, size and 
    ' other basic properties.
    Me.dataGridView1 = New DataGridView()
    Me.bindingSource1 = New BindingSource()
    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")
    
    ' Set the data source to the DataSet.
    bindingSource1.DataSource = set1
    
    'Set the DataMember to the Menu table.
    bindingSource1.DataMember = "Menu"
    
    ' Add the control data bindings.
    dataGridView1.DataSource = bindingSource1
    textBox1.DataBindings.Add("Text", bindingSource1, "Beverages", _
        True, DataSourceUpdateMode.OnPropertyChanged)
    textBox2.DataBindings.Add("Text", bindingSource1, "Beverages", _
        True, DataSourceUpdateMode.OnPropertyChanged)


End Sub

Private Sub bindingSource1_BindingComplete(ByVal sender As Object, _
    ByVal e As BindingCompleteEventArgs) Handles bindingSource1.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

編譯程式碼

另請參閱