objective-c - 據說iOS7.0之後會遇到這種錯,可我又不知道錯在哪,怎麼搞,求解?

Question

<Error>: CGBitmapContextCreate: unsupported parameter combination: set CGBITMAP_CONTEXT_LOG_ERRORS environmental variable to see the details
Dec 27 16:20:34  AppPink[33402] <Error>: CGContextDrawImage: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.
Dec 27 16:20:34  AppPink[33402] <Error>: CGBitmapContextCreateImage: invalid context 0x0. If you want to see the backtrace, please set CG_CONTEXT_SHOW_BACKTRACE environmental variable.

百度了很多都是英文的,看不太懂.....