問題描述
我有一個大的 UIView.它的大小可變.它可能大于 5000x5000 size.我使用 UIBezierPath 在其上繪制線條、圓圈.我還在上面添加了一些 view.這些 subview 中的每一個都包含 buttons、textview、labels 等.
I have an large UIView. Its variable size. It may be larger than 5000x5000 size. I draw lines, circles on it using UIBezierPath. Also I add some view's on it. Each of these subview's contains buttons, textview, labels, etc.
我把這個主視圖放在 UIScrollView 上.UIScrollView 是 zoomable 并且必須非常清晰地顯示內容(它不應該變得模糊).
I placed this main view on UIScrollView. UIScrollView is zoomable and have to show the contents very sharply (It should not get blurred).
目前，我繪制完整的 UIView 并添加到 UIScrollView.問題是，由于內存壓力問題，它占用了太多的memory和崩潰.
Currently, I draw complete UIView and added on UIScrollView. The problem is that, Its taking too much memory and crashing because of Memory Pressure Issue.
我應該如何處理以實現高性能?
How should I handle this to achieve high performance?
推薦答案
繼承UIView并在其中實現+layerClass方法:
Subclass UIView and implement the +layerClass method in it:
+layerClass
{
return [CATiledLayer class];
}
這會導致您的視圖由 CATiledLayer 而不是單個巨大的 CALayer 支持(在該大小下會消耗太多內存).
This causes your view to be backed by CATiledLayer instead of a single, huge CALayer (which would consume too much memory at that size).
然后，您只需在自定義視圖類中實現 -(void)drawRect:(CGRect)rect 并在其中完成所有繪圖.我最近在我的項目中必須這樣做，該項目使用 UIScrollViews 滾動一個可以達到 10000 x 150000 的區域.
Then you just implement -(void)drawRect:(CGRect)rect in your custom view class and do all of your drawing in there. I had to do this recently in my project which uses UIScrollViews to scroll over an area that can be as big as 10000 x 150000.
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