MouseWheelEventArgs 类

定义

public ref class MouseWheelEventArgs : System::Windows::Input::MouseEventArgs

public class MouseWheelEventArgs : System.Windows.Input.MouseEventArgs

type MouseWheelEventArgs = class
    inherit MouseEventArgs

Public Class MouseWheelEventArgs
Inherits MouseEventArgs

继承

Object

EventArgs

RoutedEventArgs

InputEventArgs

MouseEventArgs

MouseWheelEventArgs

示例

以下示例TextBox在鼠标滚轮为正数时向上移动 ，如果鼠标滚轮DeltaDelta为负数，则向下移动 TextBox 。 附加到 TextBoxCanvas。

// Moves the TextBox named box when the mouse wheel is rotated.
// The TextBox is on a Canvas named MainCanvas.
private void MouseWheelHandler(object sender, MouseWheelEventArgs e)
{
    // If the mouse wheel delta is positive, move the box up.
    if (e.Delta > 0)
    {
        if (Canvas.GetTop(box) >= 1)
        {
            Canvas.SetTop(box, Canvas.GetTop(box) - 1);
        }
    }

    // If the mouse wheel delta is negative, move the box down.
    if (e.Delta < 0)
    {
        if ((Canvas.GetTop(box) + box.Height) <= (MainCanvas.Height))
        {
            Canvas.SetTop(box, Canvas.GetTop(box) + 1);
        }
    }
}

' Moves the TextBox named box when the mouse wheel is rotated.
' The TextBox is on a Canvas named MainCanvas.
Private Sub MouseWheelHandler(ByVal sender As Object, ByVal e As MouseWheelEventArgs)
    ' If the mouse wheel delta is positive, move the box up.
    If e.Delta > 0 Then
        If Canvas.GetTop(box) >= 1 Then
            Canvas.SetTop(box, Canvas.GetTop(box) - 1)
        End If
    End If

    ' If the mouse wheel delta is negative, move the box down.
    If e.Delta < 0 Then
        If (Canvas.GetTop(box) + box.Height) <= MainCanvas.Height Then
            Canvas.SetTop(box, Canvas.GetTop(box) + 1)
        End If
    End If

End Sub

注解

MouseWheelEventArgs 与以下事件一起使用：

• UIElement.MouseWheel

• ContentElement.MouseWheel

• Mouse.MouseWheel (附加事件)

• UIElement.PreviewMouseWheel

• ContentElement.PreviewMouseWheel

• Mouse.PreviewMouseWheel (附加事件)

Delta如果鼠标滚轮向上或向前移动 (远离用户) ，则属性为正数;如果鼠标滚轮向下或向后移动，则属性为正 (向用户) 。

即使鼠标滚轮移动较小，也会引发此事件。 对于某些方案，适合实现处理程序，通过检查增量是否超过特定阈值来限制小鼠标滚轮增量。 否则，如果鼠标滚轮增量太小，以至于与鼠标滚轮移动相关的任何 UI 都不会更新，则可以调用处理程序。 在处理程序中实现阈值行为的确切方式以及该阈值应是什么完全特定于实现。

构造函数

属性

方法

适用于

另请参阅

• MouseWheelDeltaForOneLine