MouseWheelEventArgs.Delta 属性

public:
 property int Delta { int get(); };

public int Delta { get; }

member this.Delta : int

Public ReadOnly Property Delta As Integer

属性值

滚轮已更改的量。 如果鼠标滚轮向向上方向（远离用户）旋转，或者鼠标滚轮在向下方向（向用户旋转），则此值为正值。

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TextBox为负时向下移动Delta。 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

此值的有效上限和较低范围可能来自引发事件的设备实现或其他调用方，因此未定义。

另请参阅

• MouseWheelDeltaForOneLine