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

以下示例在鼠标滚轮为正时向上移动TextBox，并在鼠标滚Delta轮Delta为负时向下移动TextBox。 附加到 TextBox .Canvas

// 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 用于以下事件：

• UIElement.MouseWheel

• ContentElement.MouseWheel

• Mouse.MouseWheel （附加事件）

• UIElement.PreviewMouseWheel

• ContentElement.PreviewMouseWheel

• Mouse.PreviewMouseWheel （附加事件）

如果鼠标滚轮向上或向前移动（远离用户），或者如果鼠标滚轮向下或向后移动（向用户移动），则 Delta 此属性为正值。

即使对于小型鼠标滚轮移动，也会引发此事件。 在某些情况下，通过检查增量是否超过特定阈值，实现限制小型鼠标滚轮增量的处理程序是适当的。 否则，对于鼠标滚轮增量如此小的情况，你可能会调用处理程序，以至于任何绑定到鼠标滚轮移动的 UI 都不会更新。 确切地说，如何在处理程序中实现阈值行为，以及该阈值应完全特定于实现的行为。

另请参阅

• MouseWheelDeltaForOneLine