Question

我一直试图通过TranslateTransform在画布中翻译网格（2个线阵列）。然而，线条只是摇晃并回到原来的地方而不翻译。这是来源：

    private Point mousePosition;
    private bool CanvasMouseDown;

    private void GraphMouseDown(object sender, MouseButtonEventArgs e)
    {
        CanvasMouseDown = true;
    }

    private void GraphMouseMove(object sender, MouseEventArgs e)
    {
        if (CanvasMouseDown)
        {
            var position = e.GetPosition(canvas);
            var offset = position - mousePosition;
            mousePosition = position;

            for (int i = 0; i < GridLinesHoriz.Length; ++i)
            {
                GridLinesHoriz[i].RenderTransform = new TranslateTransform(offset.X, offset.Y);
            }

            for (int i = 0; i < GridLinesVert.Length; ++i)
            {
                GridLinesVert[i].RenderTransform = new TranslateTransform(offset.X, offset.Y);
            }
        }
    }


    private void GraphMouseUp(object sender, MouseButtonEventArgs e)
    {
        CanvasMouseDown = false;
    }

任何帮助？

Answer 1

问题是您在处理MouseMove事件时正在规范偏移量。 TranslateTransform始终从原始位置进行转换，因此您需要计算在拖动操作的生命周期内维护的运行偏移量。

如果将mousePosition更改为类级变量并在操作开始时设置该变量（在MouseDown事件处理程序中）并停止在MouseMove事件处理程序中更新该变量，行将开始翻译你期望的方式。

point mousePosition;

private void GraphMouseDown(object sender, MouseButtonEventArgs e)
{
    CanvasMouseDown = true;
    mousePosition  = e.GetPosition(canvas);
}

private void GraphMouseMove(object sender, MouseEventArgs e)
{
    if (CanvasMouseDown)
    {
        var position = e.GetPosition(canvas);
        var offset = position - mousePosition;

        for (int i = 0; i < GridLinesHoriz.Length; ++i)
        {
            GridLinesHoriz[i].RenderTransform = new TranslateTransform(offset.X, offset.Y);
        }

        for (int i = 0; i < GridLinesVert.Length; ++i)
        {
            GridLinesVert[i].RenderTransform = new TranslateTransform(offset.X, offset.Y);
        }
    }
}

TranslateTransform不翻译行

1 个答案: