objective-c - iOS 7.0 下的无效上下文 0x0 和系统降级

Question

我已经阅读了尽可能多的关于这个可怕问题的搜索结果，不幸的是，每个搜索结果似乎都专注于特定的函数调用。

我的问题是我从多个函数中得到相同的错误，我猜这是从我使用的函数中回调的。

更糟糕的是，实际代码位于自定义私有(private)框架中，该框架正在导入另一个项目中，因此调试不是那么简单？

谁能指出我正确的方向？我有一种感觉，我错误地调用了某些方法或使用了错误的上下文，但此时 xcode 的输出并不是很有帮助。

: CGContextSetFillColorWithColor: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

: CGContextSetStrokeColorWithColor: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

CGContextSaveGState: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

: CGContextSetFlatness: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

: CGContextAddPath: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

: CGContextDrawPath: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

: CGContextRestoreGState: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

: CGContextGetBlendMode: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

当呈现自定义 View 或其继承的类之一时，可能会发生这些错误。此时它们会产生多次，直到键盘不提供任何输入。触摸事件仍在注册中，但系统速度变慢，最终可能导致未分配对象错误。

编辑#1:我确实可以访问正在导入的框架，但我没有在导致问题的类中看到任何奇怪的东西。

编辑 #2: 我刚刚收到一封电子邮件，说 iOS 7.1 已经发布给开发者。我很想知道这是否会消失，或者变得更糟，或者可以解决。

Answer 1

如果您想知道是什么代码导致了这些日志，您可以 add a symbolic breakpoint在 CGPostError 上。