关于这个可怕的问题,我已经阅读了尽可能多的搜索结果,不幸的是,每个搜索结果似乎都集中在一个特定的函数调用上。

我的问题是,我从多个函数得到相同的错误,我猜是从我使用的函数回调的。

更糟糕的是,实际的代码是在另一个项目中导入的自定义私有框架中,因此,调试不是那么简单吗?

有人能告诉我正确的方向吗?我有一种感觉,我正在错误地调用某些方法或与坏的上下文,但xcode的输出在这一点上不是很有帮助。

: 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.

当呈现自定义视图或其继承的类之一时,可能会发生这些错误。这时它们会生成多次,直到键盘不再提供任何输入。触摸事件仍然被注册,但是系统变慢,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,但我没有看到导致问题的类中有任何奇怪的东西。

编辑#2:我刚刚收到一封电子邮件,iOS 7.1已经发布给开发者了。我很好奇这种情况是否会消失,或者变得更糟,或者是否能得到解决。


当前回答

对我来说,答案是我不必要地释放了drawRect:中的图形上下文。在CGPostError上抛出一个符号断点使我找到了罪魁祸首。

其他回答

直接回答: 这个问题是因为你已经使用了核心图形元素,如CGContext等,而不是- (void)drawRect:(CGRect)rect这个方法。

现在请将代码移到该方法。它将停止给你警告/错误。

我有这个问题与一个简单的UITextField(键盘不显示和许多不同的无效上下文错误消息在控制台)。 我只是通过查找SO上的另一个问题找到了一个解决方案:无法找到CFBundle CertUIFramework.axbundle的可执行文件

只做:

点击iOS模拟器>重置内容和设置…然后再跑。

问题不应该再存在了

I have had cases where the context returned from UIGraphicsGetCurrentContext() is NULL, and if you try using it for anything this message appears. It is the view's responsibility to push a context using UIGraphicsPushContext prior to calling drawRect:, if you call drawRect: directly instead of [view setNeedsDisplay] you risk the context not being set yet. My hunch is that prior to iOS 7 the context was pushed for the view on init, and now on iOS 7 the context isn't pushed until the first time drawRect: is about to be called. I suspect some UIKit code is calling drawRect: directly and this is why there are issues with some code even when no custom drawing is being done.

解决方案(如果做自定义绘图):

不要直接调用drawRect:,使用[view setNeedsDisplay],或者如果你需要立即绘图,使用[view。层画) 在你的drawRect:获取上下文,但不要在if语句体之外使用if (context) {<do drawing here>}

对我来说,我得到这个错误,因为我正在释放CGContextRef,如下所示:

- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();

    // DRAW BACKGROUND CIRCLE
    CGContextSetFillColorWithColor(context, [[UIColor gray] colorWithAlphaComponent:0.6].CGColor);
    CGContextFillEllipseInRect(context, rect);

//    CGContextRelease(context);
}

删除版本解决了这个问题

我有同样的问题,我忘记导入QuartzCore/QuartzCore.h,这解决了我的问题与这些错误。

    #import <QuartzCore/QuartzCore.h>