GraphicsPath和OutOfMemoryException

Question

我有以下内容

private bool IsPathVisible(Rectangle detectorRectangle, GraphicsPath path, Pen pen)
{
    path.Widen(pen);
    return IsPathVisible(detectorRectangle, path);
}

当pathpoint是相同的点时,我收到一个OutOfMemoryException(使用Widen函数).

我该如何管理它？

Answer 1

这是笔和扩展方法的错误.确保路径的起点和路径的终点不相同.

这是一个演示:

private void panel1_Paint(object sender, PaintEventArgs e)
{
  //This works:
  using (GraphicsPath path = new GraphicsPath())
  {
    path.AddLine(new Point(16, 16), new Point(20, 20));
    path.Widen(Pens.Black);
    e.Graphics.DrawPath(Pens.Black, path);
  }

  //This does not:
  using (GraphicsPath path = new GraphicsPath())
  {
    path.AddLine(new Point(20, 20), new Point(20, 20));
    path.Widen(Pens.Black);
    e.Graphics.DrawPath(Pens.Black, path);
  }
}

以下是向Microsoft报告的地方:如果路径只有一个点,则GraphicsPath.Widen会抛出OutOfMemoryException