ManipulationDeltaEventArgs.IsInertial 属性
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
获取一个值,该值指示 ManipulationDelta 事件是否在惯性期间发生。
public:
property bool IsInertial { bool get(); };
public bool IsInertial { get; }
member this.IsInertial : bool
Public ReadOnly Property IsInertial As Boolean
属性值
如果在惯性运动期间发生 ManipulationDelta 事件,则为 true
;如果在用户接触 UIElement 过程中发生该事件,则为 false
。
示例
以下示例演示事件的事件处理程序 ManipulationDelta 。 该示例检查事件是否 ManipulationDelta 在惯性期间发生,以及矩形是否触摸窗口的边缘。 如果这些情况为 true,应用程序将停止操作,以防止矩形离开应用程序的可见区域。 此示例是 演练:创建第一个触摸应用程序中较大示例的一部分。
void Window_ManipulationDelta(object sender, ManipulationDeltaEventArgs e)
{
// Get the Rectangle and its RenderTransform matrix.
Rectangle rectToMove = e.OriginalSource as Rectangle;
Matrix rectsMatrix = ((MatrixTransform)rectToMove.RenderTransform).Matrix;
// Rotate the Rectangle.
rectsMatrix.RotateAt(e.DeltaManipulation.Rotation,
e.ManipulationOrigin.X,
e.ManipulationOrigin.Y);
// Resize the Rectangle. Keep it square
// so use only the X value of Scale.
rectsMatrix.ScaleAt(e.DeltaManipulation.Scale.X,
e.DeltaManipulation.Scale.X,
e.ManipulationOrigin.X,
e.ManipulationOrigin.Y);
// Move the Rectangle.
rectsMatrix.Translate(e.DeltaManipulation.Translation.X,
e.DeltaManipulation.Translation.Y);
// Apply the changes to the Rectangle.
rectToMove.RenderTransform = new MatrixTransform(rectsMatrix);
Rect containingRect =
new Rect(((FrameworkElement)e.ManipulationContainer).RenderSize);
Rect shapeBounds =
rectToMove.RenderTransform.TransformBounds(
new Rect(rectToMove.RenderSize));
// Check if the rectangle is completely in the window.
// If it is not and intertia is occuring, stop the manipulation.
if (e.IsInertial && !containingRect.Contains(shapeBounds))
{
e.Complete();
}
e.Handled = true;
}
Private Sub Window_ManipulationDelta(ByVal sender As Object, ByVal e As ManipulationDeltaEventArgs)
' Get the Rectangle and its RenderTransform matrix.
Dim rectToMove As Rectangle = e.OriginalSource
Dim rectTransform As MatrixTransform = rectToMove.RenderTransform
Dim rectsMatrix As Matrix = rectTransform.Matrix
' Rotate the shape
rectsMatrix.RotateAt(e.DeltaManipulation.Rotation,
e.ManipulationOrigin.X,
e.ManipulationOrigin.Y)
' Resize the Rectangle. Keep it square
' so use only the X value of Scale.
rectsMatrix.ScaleAt(e.DeltaManipulation.Scale.X,
e.DeltaManipulation.Scale.X,
e.ManipulationOrigin.X,
e.ManipulationOrigin.Y)
'move the center
rectsMatrix.Translate(e.DeltaManipulation.Translation.X,
e.DeltaManipulation.Translation.Y)
' Apply the changes to the Rectangle.
rectTransform = New MatrixTransform(rectsMatrix)
rectToMove.RenderTransform = rectTransform
Dim container As FrameworkElement = e.ManipulationContainer
Dim containingRect As New Rect(container.RenderSize)
Dim shapeBounds As Rect = rectTransform.TransformBounds(
New Rect(rectToMove.RenderSize))
' Check if the rectangle is completely in the window.
' If it is not and intertia is occuring, stop the manipulation.
If e.IsInertial AndAlso Not containingRect.Contains(shapeBounds) Then
e.Complete()
End If
e.Handled = True
End Sub
注解
可以使用此方法来确定事件是在 ManipulationDelta 惯性期间还是当用户与接收 ManipulationDelta 事件的元素接触时发生。