objective-c - CATiledlayer setContents nil 让我崩溃

Question

我有一个带有 CATiledlayer 的 uiview。我想重用视图，所以我写道：

self.layer.contents = nil; 
[self.layer setNeedDisplay]; 

但我遇到了随机崩溃。堆栈跟踪如下：

0 libsystem_kernel.dylib 0x3929908c __psynch_cvwait + 24
1 libsystem_c.dylib 0x391f4f19 pthread_cond_wait + 41
2 QuartzCore 0x32d3b205 CAImageProviderSetCallback + 189
3 QuartzCore 0x32dc600d -[CATiledLayer setContents:] + 73
4 TBClient 0x000933ed -[TBRichTextView drawRichTextContent] (TBRichTextView.m:114)

谁能帮我解决这个问题？