为什么使用笔与划线模式导致在WPF自定义的2D绘图巨大（！）性能下降？ [英] Why does use of pens with dash patterns cause huge (!) performance degredation in WPF custom 2D drawing?

问题描述

希望任何人都可以阐明这个角度，所以我可以用钢笔用破折号模式？

我写一个滚动的图表（A 面板在的ScrollViewer 实现 IScrollInfo ）在WPF中使用 DrawingVisual 的 DataContext.Draw 的 X 的。我有几千个 DrawingVisual s表示获得面板上滚动使用 TranslateTransform 承载它们。我通过把面板在它的上面，并绘制简单的水平线从一个边缘到另一个使用 DataContext.DrawLine（笔，新实施的网格点（0，Y），新点（widthOfPanel，Y））; //（注：这些行总是静态的，他们从来不动）。

滚动性能是绝对疯狂（即DrawingVisual的会立即绘制和滚动是即时的）。但是，如果我用笔使用破折号模式（参见下面的例子）提请网格线，然后滚动很生涩的表现似乎已经减少了一100（估计值）的因素。任何人都可以解释为什么会发生，我怎么能解决这个？

笔与虚线图案示例：

 ＆LT;笔X：关键=PenUsingDashPatterns刷=黑厚度=1＆GT;
   ＆LT; Pen.DashStyle＆GT;
      ＆LT; D​​ashStyle破折号=3,3/＆GT;
   ＆LT; /Pen.DashStyle>
＆LT; /笔＆GT;
 

解决方案

是笔渐冻？冻结图形对象有助于性能提升不少。

您可以建立一个加载的处理程序和调试，看看您的笔被冻结。如果没有，请手动呼吁他们的Pen.Freeze（）按钮。

请注意，冻结也使笔只读...你将无法修改它们后，冻结他们。

Hope anyone can shed light on this so I can use pens with dash patterns?

I am writing a scrollable chart (a Panel inside ScrollViewer that implements IScrollInfo) in WPF using DrawingVisual's DataContext.DrawX. I have several thousand DrawingVisuals that get scrolled by using TranslateTransform on the Panel that hosts them. I implemented a grid by placing a Panel on top of it and drawing simple horizontal lines from one edge to the other using DataContext.DrawLine(pen, new Point(0, y), new Point(widthOfPanel, y)); //(note: these lines are always static, they never move).

The scroll performance is absolutely insane (i.e. DrawingVisual's are drawn instantly and scrolling is instant). But if I use a Pen that uses dash patterns (see below for example) to draw the grid lines, then scrolling is very jerky and the performance seems to have been decreased by a factor of 100 (an estimate). Can anyone explain why that happens and how I can workaround this?

Example of Pen with dash pattern:

<Pen x:Key="PenUsingDashPatterns" Brush="Black" Thickness="1">
   <Pen.DashStyle >
      <DashStyle Dashes="3, 3" />
   </Pen.DashStyle>
</Pen>

解决方案

Are the pens getting frozen? Freezing drawing objects helps performance a lot.

You could set up a Loaded handler and debug to see if your pens are frozen. If not, Call the Pen.Freeze() button manually on them.

Note that freeze also makes the pens read-only... you will be unable to modify them after you freeze them.

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