BindingManagerBase.BindingComplete 事件
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
在数据绑定操作完成时发生。
public:
event System::Windows::Forms::BindingCompleteEventHandler ^ BindingComplete;
public event System.Windows.Forms.BindingCompleteEventHandler BindingComplete;
member this.BindingComplete : System.Windows.Forms.BindingCompleteEventHandler
Public Custom Event BindingComplete As BindingCompleteEventHandler
事件类型
示例
下面的代码示例演示如何处理 BindingComplete 事件,并确保当其中一个控件值发生更改时,绑定到同一数据源的多个控件保持同步。 若要运行此示例,请将代码粘贴到 Windows 窗体中, InitializeControlsAndData
然后从窗体的构造函数或 Load 事件处理方法调用 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
注解
该 BindingComplete 事件在数据绑定操作完成后发生,其中可能包括以下内容:
将数据源中的信息推送到其绑定控件的 属性中。
将绑定控件中的信息拉取到其关联的数据源中。
请注意,无论绑定操作的完成状态如何,都会引发此事件,尽管可以通过检查 BindingCompleteState 与事件关联的参数的 BindingCompleteEventArgs 属性来确定此状态。
BindingCompleteEventArgs 还可能包含错误和异常信息。 例如,尝试将 null 值从数据源推送到控件的 DateTimePicker 绑定操作将生成异常,因为 DateTime 不能是 null
。 在这种情况下,尽管绑定操作未成功完成,但 BindingComplete 将引发事件,并且事件将包含有关绑定尝试失败的信息。