Question

我尝试使用ManipulationDelta event wpf实现多点触控ui（在棕色地块项目中）。但我只获得翻译价值，但从不进行规模或轮换。

我的测试代码如下：

        Private Sub ScrollViewerViewModelManipulationDelta(sender As Object, e As Input.ManipulationDeltaEventArgs) Handles Me.ManipulationDelta

        Dim transform As MatrixTransform = TryCast(RenderTransform, MatrixTransform)
        If transform Is Nothing Then transform = New MatrixTransform(RenderTransform.Value)
        Dim matrix As Matrix = transform.Matrix

        If e.DeltaManipulation.Scale.X <> 1 OrElse e.DeltaManipulation.Scale.Y <> 1 Then
            matrix.ScaleAt(e.DeltaManipulation.Scale.X,
                            e.DeltaManipulation.Scale.Y,
                            e.ManipulationOrigin.X,
                            e.ManipulationOrigin.Y)
        End If
        If e.DeltaManipulation.Translation.X <> 1 OrElse e.DeltaManipulation.Translation.Y <> 1 Then
            'matrix.Translate(e.DeltaManipulation.Translation.X,
            '                e.DeltaManipulation.Translation.Y)
        End If
        If e.DeltaManipulation.Rotation <> 0 Then
            matrix.RotateAt(e.DeltaManipulation.Rotation,
                 e.ManipulationOrigin.X,
                 e.ManipulationOrigin.Y)
        End If

        RenderTransform = New MatrixTransform(matrix)

        If e.IsInertial Then
            e.Complete()
        End If

        'e.Handled = True

    End Sub

知道我在这里缺少什么吗？我尝试了缩放和旋转的手势，但我只能翻译...

谢谢！斯蒂芬

Answer 1

您必须在ManipulationStarted事件处理程序中调用Manipulation.SetManipulationMode：

private void ScrollViewerViewModelManipulationStarted(
    object sender, ManipulationStartedEventArgs e)
{
    Manipulation.SetManipulationMode((UIElement)sender, ManipulationModes.All);
}

ManipulationDelta - 只有翻译有值，缩放和旋转总是'身份'

1 个答案: