HtmlElement.Focusing 事件

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

当元素首次接收用户输入焦点时发生。

public:
 event System::Windows::Forms::HtmlElementEventHandler ^ Focusing;

public event System.Windows.Forms.HtmlElementEventHandler Focusing;

member this.Focusing : System.Windows.Forms.HtmlElementEventHandler 

Public Custom Event Focusing As HtmlElementEventHandler 

事件类型

HtmlElementEventHandler

示例

下面的代码示例演示了此成员的用法。 在此示例中，事件处理程序报告事件的发生情况 Focusing 。 此报告可帮助你了解事件发生的时间，并可以帮助你进行调试。

若要运行示例代码，请将其粘贴到包含名为 HtmlElement1的类型的HtmlElement实例的项目中。 然后，确保事件处理程序与 Focusing 事件相关联。

private void HtmlElement1_Focusing(Object sender, HtmlElementEventArgs e) {

System.Text.StringBuilder messageBoxCS = new System.Text.StringBuilder();
messageBoxCS.AppendFormat("{0} = {1}", "MouseButtonsPressed", e.MouseButtonsPressed );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "ClientMousePosition", e.ClientMousePosition );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "OffsetMousePosition", e.OffsetMousePosition );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "MousePosition", e.MousePosition );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "BubbleEvent", e.BubbleEvent );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "KeyPressedCode", e.KeyPressedCode );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "AltKeyPressed", e.AltKeyPressed );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "CtrlKeyPressed", e.CtrlKeyPressed );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "ShiftKeyPressed", e.ShiftKeyPressed );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "EventType", e.EventType );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "ReturnValue", e.ReturnValue );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "FromElement", e.FromElement );
messageBoxCS.AppendLine();
messageBoxCS.AppendFormat("{0} = {1}", "ToElement", e.ToElement );
messageBoxCS.AppendLine();
MessageBox.Show(messageBoxCS.ToString(), "Focusing Event" );
}

Private Sub HtmlElement1_Focusing(sender as Object, e as HtmlElementEventArgs) _ 
     Handles HtmlElement1.Focusing

    Dim messageBoxVB as New System.Text.StringBuilder()
    messageBoxVB.AppendFormat("{0} = {1}", "MouseButtonsPressed", e.MouseButtonsPressed)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "ClientMousePosition", e.ClientMousePosition)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "OffsetMousePosition", e.OffsetMousePosition)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "MousePosition", e.MousePosition)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "BubbleEvent", e.BubbleEvent)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "KeyPressedCode", e.KeyPressedCode)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "AltKeyPressed", e.AltKeyPressed)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "CtrlKeyPressed", e.CtrlKeyPressed)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "ShiftKeyPressed", e.ShiftKeyPressed)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "EventType", e.EventType)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "ReturnValue", e.ReturnValue)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "FromElement", e.FromElement)
    messageBoxVB.AppendLine()
    messageBoxVB.AppendFormat("{0} = {1}", "ToElement", e.ToElement)
    messageBoxVB.AppendLine()
    MessageBox.Show(messageBoxVB.ToString(),"Focusing Event")

End Sub

注解

当用户切换回应用程序时，用户使用任务栏或 ALT+TAB 键切换到另一个应用程序之前具有焦点的元素将再次接收 Focusing 和 GotFocus 事件。

无法取消此事件的默认行为。 若要从元素中删除焦点，请从 事件中GotFocus调用Focus其他元素。

Focusing元素上的事件也会在该元素的父级和类本身上HtmlDocument发生，除非将 类的 HtmlElementEventArgs 属性设置为 BubbleEventtrue。

另请参阅

• onfocusin 事件