GiveFeedbackEventArgs GiveFeedbackEventArgs GiveFeedbackEventArgs GiveFeedbackEventArgs Class

定义

提供数据GiveFeedback拖动操作期间发生的事件。Provides data for the GiveFeedback event, which occurs during a drag operation.

public ref class GiveFeedbackEventArgs : EventArgs
[System.Runtime.InteropServices.ComVisible(true)]
public class GiveFeedbackEventArgs : EventArgs
type GiveFeedbackEventArgs = class
    inherit EventArgs
Public Class GiveFeedbackEventArgs
Inherits EventArgs
继承
GiveFeedbackEventArgsGiveFeedbackEventArgsGiveFeedbackEventArgsGiveFeedbackEventArgs
属性

示例

下面的示例演示两个之间拖放操作ListBox控件。The following example demonstrates a drag-and-drop operation between two ListBox controls. 此示例调用DoDragDrop当拖动操作开始时的方法。The example calls the DoDragDrop method when the drag action starts. 如果已移动鼠标拖动操作启动多个SystemInformation.DragSize鼠标位置在从MouseDown事件。The drag action starts if the mouse has moved more than SystemInformation.DragSize from the mouse location during the MouseDown event. IndexFromPoint方法用于确定要在拖动的项的索引MouseDown事件。The IndexFromPoint method is used to determine the index of the item to drag during the MouseDown event.

示例还演示如何使用自定义光标拖放操作。The example also demonstrates using custom cursors for the drag-and-drop operation. 该示例假定两个光标文件3dwarro.cur3dwno.cur、 存在于应用程序目录,用于自定义拖动和不可拖动光标,分别。The example assumes that two cursor files, 3dwarro.cur and 3dwno.cur, exist in the application directory, for the custom drag and no-drop cursors, respectively. 如果将使用自定义光标UseCustomCursorsCheckCheckBox检查。The custom cursors will be used if the UseCustomCursorsCheckCheckBox is checked. 在中设置自定义光标GiveFeedback事件处理程序。The custom cursors are set in the GiveFeedback event handler.

键盘状态进行评估DragOver事件处理程序的权利ListBox,以确定拖动操作将是根据 SHIFT、 CTRL、 ALT 或 CTRL + ALT 键的状态。The keyboard state is evaluated in the DragOver event handler for the right ListBox, to determine what the drag operation will be based upon state of the SHIFT, CTRL, ALT, or CTRL+ALT keys. 中的位置ListBox期间还确定发生下拉DragOver事件。The location in the ListBox where the drop would occur is also determined during the DragOver event. 如果要删除的数据不是String,则DragEventArgs.Effect设置为DragDropEffects.NoneIf the data to drop is not a String, then the DragEventArgs.Effect is set to DragDropEffects.None. 最后,在显示状态的下拉DropLocationLabel LabelFinally, the status of the drop is displayed in the DropLocationLabelLabel.

若要删除的权利的数据ListBox在中确定DragDrop事件处理程序和String值中的适当位置添加ListBoxThe data to drop for the right ListBox is determined in the DragDrop event handler and the String value is added at the appropriate place in the ListBox. 如果拖动操作移动边界以外的窗体,则在取消拖放操作QueryContinueDrag事件处理程序。If the drag operation moves outside the bounds of the form, then the drag-and-drop operation is canceled in the QueryContinueDrag event handler.

这段代码摘录演示了如何使用GiveFeedbackEventArgs类。This code excerpt demonstrates using the GiveFeedbackEventArgs class. 请参阅DoDragDrop完整的代码示例的方法。See the DoDragDrop method for the complete code example.

void ListDragSource_GiveFeedback( Object^ /*sender*/, System::Windows::Forms::GiveFeedbackEventArgs^ e )
{
   // Use custom cursors if the check box is checked.
   if ( UseCustomCursorsCheck->Checked )
   {
      // Sets the custom cursor based upon the effect.
      e->UseDefaultCursors = false;
      if ( (e->Effect & DragDropEffects::Move) == DragDropEffects::Move )
                  ::Cursor::Current = MyNormalCursor;
      else
                  ::Cursor::Current = MyNoDropCursor;
   }
}
private void ListDragSource_GiveFeedback(object sender, System.Windows.Forms.GiveFeedbackEventArgs e) 
{
    // Use custom cursors if the check box is checked.
    if (UseCustomCursorsCheck.Checked) {

        // Sets the custom cursor based upon the effect.
        e.UseDefaultCursors = false;
        if ((e.Effect & DragDropEffects.Move) == DragDropEffects.Move)
            Cursor.Current = MyNormalCursor;
        else 
            Cursor.Current = MyNoDropCursor;
    }

}
Private Sub ListDragSource_GiveFeedback(ByVal sender As Object, ByVal e As GiveFeedbackEventArgs) Handles ListDragSource.GiveFeedback

    ' Use custom cursors if the check box is checked.
    If (UseCustomCursorsCheck.Checked) Then

        ' Set the custom cursor based upon the effect.
        e.UseDefaultCursors = False
        If ((e.Effect And DragDropEffects.Move) = DragDropEffects.Move) Then
            Cursor.Current = MyNormalCursor
        Else
            Cursor.Current = MyNoDropCursor
        End If
    End If

End Sub

注解

GiveFeedback拖动操作期间发生的事件。The GiveFeedback event occurs during a drag operation. 它允许拖放事件可以修改鼠标指针的外观,以便为用户可视反馈提供拖放操作期间的源。It allows the source of a drag event to modify the appearance of the mouse pointer in order to give the user visual feedback during a drag-and-drop operation. 一个GiveFeedbackEventArgs对象指定的拖放操作和是否使用默认游标类型。A GiveFeedbackEventArgs object specifies the type of drag-and-drop operation and whether default cursors are used.

有关事件模型的信息,请参阅处理和引发事件For information about the event model, see Handling and Raising Events.

构造函数

GiveFeedbackEventArgs(DragDropEffects, Boolean) GiveFeedbackEventArgs(DragDropEffects, Boolean) GiveFeedbackEventArgs(DragDropEffects, Boolean) GiveFeedbackEventArgs(DragDropEffects, Boolean)

初始化 GiveFeedbackEventArgs 类的新实例。Initializes a new instance of the GiveFeedbackEventArgs class.

属性

Effect Effect Effect Effect

获取显示的拖放操作反馈。Gets the drag-and-drop operation feedback that is displayed.

UseDefaultCursors UseDefaultCursors UseDefaultCursors UseDefaultCursors

获取或设置拖动操作是否应使用与拖放效果关联的默认光标。Gets or sets whether drag operation should use the default cursors that are associated with drag-drop effects.

方法

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

作为默认哈希函数。Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

获取当前实例的 TypeGets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

返回表示当前对象的字符串。Returns a string that represents the current object.

(Inherited from Object)

适用于