Question

我需要更改某些注释对象的RenderTransformOrigin属性，以便它们始终围绕另一侧（x）的中心（y）旋转。

因此，让我们说用户点击对象的右侧，然后旋转点将是（0.0,0.5），但是如果用户希望从项目的另一侧更改旋转，然后他可以点击它的左侧，在这种情况下，旋转点变为（1.0,0.5）。

问题：我要求帮助的原因是，只要发生这种情况，项目就会跳到屏幕上。它的移动量取决于物品的角度（如果它根本不旋转，那么它根本不会移动）。角度本身在运动过程中不会改变，只有位置。（我意识到在没有图像的情况下理解这个问题有点困难，但由于stackoverflow的规则，我不允许附加图像以使事情变得更容易。）所以这只会在选择另一方时发生（例如单击右侧后的左侧），移动/跳跃取决于角度（角度越大，跳跃越大）。

我想要做的是更改提到的属性，以便在对象的选定边缘周围发生旋转，而不会在更改边时对象保持上下跳跃。

感谢您的帮助！

修改[2015-03-10_12-17-21]

class XYZ  
{  
...  
private void RotateThumb_DragStarted(object sender, DragStartedEventArgs e) {
    m_rotateTransform = m_designerItem.RenderTransform as RotateTransform;

    if (m_rotateTransform == null) {
        m_designerItem.RenderTransform = new RotateTransform(0);
        m_rotateTransform = m_designerItem.RenderTransform as RotateTransform;
    }
    Point positionWithinAnnotation = Mouse.GetPosition(m_designerItem);
    var selectedThumb = GetThumbPosition(m_designerItem, positionWithinAnnotation);

    double relativeCenterX = ((selectedThumb == ThumbPosition.Left) ? (1.0D) : (0.0D));
    double relativeCenterY = 0.5D;

    m_designerItem.RenderTransformOrigin = new Point(relativeCenterX, relativeCenterY);
    m_transformOrigin = m_designerItem.RenderTransformOrigin;

    m_rotationPoint = m_designerItem.TranslatePoint(
        new Point(relativeCenterX * m_designerItem.ActualWidth,
                  relativeCenterY * m_designerItem.ActualHeight),
                  m_canvas);

    Point startPoint = Mouse.GetPosition(m_canvas);
    m_startVector = Point.Subtract(startPoint, m_rotationPoint);
}

private void handleRotate(DragDeltaEventArgs e) {
    Point currentPoint = Mouse.GetPosition(m_canvas);
    Vector deltaVector = Point.Subtract(currentPoint, m_rotationPoint);

    double angle = Vector.AngleBetween(m_startVector, deltaVector);
    m_rotateTransform.Angle += Math.Round(angle, 0);
    m_startVector = deltaVector;

    m_designerItem.InvalidateMeasure();
}

...
}

Answer 1

如果没有a good, minimal, complete code example，很难确定您需要做些什么来修复代码。

也就是说，从描述中我觉得你应该使用RotateTransform.CenterX和RotateTransform.CenterY属性，而不是设置RenderTransformOrigin。

例如：

private void RotateThumb_DragStarted(object sender, DragStartedEventArgs e) {
    m_rotateTransform = m_designerItem.RenderTransform as RotateTransform;

    if (m_rotateTransform == null) {
        m_designerItem.RenderTransform = new RotateTransform();
        m_rotateTransform = m_designerItem.RenderTransform as RotateTransform;
    }
    Point positionWithinAnnotation = Mouse.GetPosition(m_designerItem);
    var selectedThumb = GetThumbPosition(m_designerItem, positionWithinAnnotation);

    double relativeCenterX = ((selectedThumb == ThumbPosition.Left) ? (1.0D) : (0.0D));
    double relativeCenterY = 0.5D;

    m_rotateTransform.CenterX = relativeCenterX;
    m_rotateTransform.CenterY = relativeCenterY;

    // Without a complete example, I'm not sure I know what this part is
    // supposed to be doing. I think it's fine, but maybe it needs to be
    // fixed too?
    m_rotationPoint = m_designerItem.TranslatePoint(
        new Point(relativeCenterX * m_designerItem.ActualWidth,
                  relativeCenterY * m_designerItem.ActualHeight),
                  m_canvas);

    Point startPoint = Mouse.GetPosition(m_canvas);
    m_startVector = Point.Subtract(startPoint, m_rotationPoint);
}

从代码中更改RenderTransformOrigin

1 个答案: