ios 如何用drawrect方法在图像上画一条线
我有一个名为 imgView 的 UIImageView，当我在视图的 drawrect 方法中画线时添加它
[self.view addSubview:imgView];
，该线显示在 imgView 下方，但我希望它显示在 imgView 上。 ps：我也尝试过
[self.view insertSubview:imgView atIndex:0];
隐藏 imgView，即我可以在视图上看到它
[self.view addSubview:imgView];
，但这
[self.view sendSubviewToBack:imgView];
也不起作用。
可能出什么问题了？
I have a UIImageView called imgView which was added by
[self.view addSubview:imgView];
when I draw line in view's drawrect method, the line shows below imgView, but i want it shows on imgView. ps: i also tried
[self.view insertSubview:imgView atIndex:0];
which hides the imgView i.e I could see it on the view
[self.view addSubview:imgView];
and
[self.view sendSubviewToBack:imgView];
that also didn't work.
What could be wrong?
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在drawRect方法中绘制图像，然后绘制线条。
Draw your image in the drawRect method, then draw the line.
我知道已经晚了，但仍然对某人有用。
line 位于图像下方的原因 - 是因为您在 drawRect 中执行的所有操作都将位于每个子视图下方。因此，如果您想要在图像顶部画一条线，则需要向 imageview 添加一个 UIView 子视图类，其中您有相应的带有线条绘制的drawrect。
I know it's late, but still, could be usefull to someone.
The reason why line is under image - is because everything you do in drawRect, will be below every subview. So if you would want a line on top of image, you would need to add to imageview an UIView subview class, in which You have corresponding drawrect with line drawing.