使用Win2D绘制可编辑和可选择的形状吗? [英] Drawing editable and selectable shapes with Win2D?

问题描述

在将Shapes添加到Canvas -controls之前，我已经使用过System.Windows.Shapes. 它们可以像对象一样使用，并且在我编辑字段时视觉效果会发生变化.我还可以为点击等添加事件处理程序.

I've used System.Windows.Shapes before to add Shapes to Canvas-controls. They can be used like objects and the visuals change as I edit the fields. I can also add event handlers for clicks etc.

我将需要使用Win2D的这种功能.有什么简单的方法吗?

I'd need this kind of functionality by using Win2D. Is there any easy way?

我正在尝试创建一个像这样的简单应用程序:

I'm trying to create a simple app like this:

• 用户可以在画布上绘制形状
• 可以通过单击选择形状并突出显示形状
• 可以对选定的形状进行操作(颜色，不透明度，宽度，高度，位置等)
• 形状可以彼此叠加(Z索引)

我猜一种方法是用Draw方法创建自定义的Shape类.然后，我只操作对象-更改将通过Draw方法反映到视觉效果.在每个画布无效时，将再次绘制对象.

I guess one way would be to create custom Shape classes with Draw-methods. I'd then only manipulate the object - and the changes would reflect to visuals thru the Draw-method. On each canvas invalidation, the objects would be drawn again.

有什么想法吗?

推荐答案

Win2D可以帮助您进行命中测试.对于具有填充颜色的几何，请使用 CanvasGeometry.FillContainsPoint(...)，对于仅具有轮廓/笔触的几何，请使用 CanvasGeometry.StrokeContainsPoint(.. .).使用这两种方法，您将获得准确的命中测试.对于非矩形形状(包括旋转的矩形)，使用边界是不准确的.

Win2D can help you with hit-testing. With geometries that have a fill color, then use CanvasGeometry.FillContainsPoint(...) and for geometries that only have an outline/stroke, use CanvasGeometry.StrokeContainsPoint(...). Using these two methods, you'll get accurate hit-testing. Using bounds is not accurate for non-rectangular shapes, including rotated rectangles.

对于z索引，您必须跟踪几何顺序，并从上到下浏览列表，直到PointerPoint达到目标为止.

For z-indexing, then you have to keep track of the order of your geometries and go through the list from top to bottom until the PointerPoint has hit something.

如果几何列表太大，并且发现有滞后，则可以先使用边界开始命中测试，如果失败，则继续进行下一项(如果命中)，然后使用上述方法获得准确的结果.阅读.

If your list of geometries is too large and you notice a lag, then you can start hit-testing using bounds first and if it fails, continue to next item, if it hits, then use the above methods to get an accurate reading.

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