通过鼠标UWP旋转视图上的Ui对象

本文关键字：Ui 对象 视图 旋转 鼠标 UWP | 更新日期: 2023-09-27 18:12:36

我需要使用鼠标旋转Image。我不知道该怎么做。现在我有了通过按

按钮来旋转的代码
 private void Rotate_Click(object sender, RoutedEventArgs e)
    {
        var button = sender as Button;
        var parent = (FrameworkElement) VisualTreeHelper.GetParent(button);
        var ct = (CompositeTransform) parent.RenderTransform;
        ct.Rotation += 5;
    }

但是我怎样才能把它改成我的要求呢?我需要拖动按钮并旋转

通过鼠标UWP旋转视图上的Ui对象

下面是一个粗略的示例，当拖动时，视图上的图像会围绕其中心旋转。

在新项目中添加XAML

<Image x:Name="TheImage"
        Source="Assets/StoreLogo.png"
        Width="200"
        Stretch="Uniform"
        RenderTransformOrigin="0.5,0.5"
        PointerPressed="OnPointerPressed"
        PointerMoved="OnPointerMoved"
        PointerReleased="OnPointerReleased">
    <Image.RenderTransform>
        <RotateTransform x:Name="ImageRotation" />
    </Image.RenderTransform>
</Image>

下面是相应的

后面的代码
private bool pointerCaptured = false;
private Point lastPosition;
private void OnPointerPressed(object sender, PointerRoutedEventArgs e)
{
    pointerCaptured = true;
    this.lastPosition = e.GetCurrentPoint(TheImage).Position;
}
private void OnPointerMoved(object sender, PointerRoutedEventArgs e)
{
    if (pointerCaptured)
    {
        Point currentLocation = e.GetCurrentPoint(this.TheImage).Position;
        double radians = Math.Atan((currentLocation.Y - lastPosition.Y) /
                                    (currentLocation.X - lastPosition.X));
        var angle = radians * 180 / Math.PI;
        // Apply a 180 degree shift when X is negative so can rotate all of the way around
        if (currentLocation.X - lastPosition.X < 0)
        {
            angle += 180;
        }
        lastPosition = currentLocation;
        this.ImageRotation.Angle = angle;
    }
}
private void OnPointerReleased(object sender, PointerRoutedEventArgs e)
{
    pointerCaptured = false;
}

关于https://stackoverflow.com/a/963099/1755

的一些旋转数学提示
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