Ios UIActionSheet showInView发出警告：无效上下文0x0

我正在尝试在self.view.parentview中显示UIActionSheet。但我在跑步时没有得到警告

<Error>: 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.
<Error>: 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.
<Error>: 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.

我已经设置了断点。但是在这一行[self.dobActionSheet showInView:self.parentViewController.view]中得到这个警告

我尝试在Viewcontroller中演示，它在第一个索引中嵌入在tabbarController中。这就是为什么，尝试使用parentViewController.view而不是self.view进行演示

注：我也看到了同样的问题。但是找不到答案

actionSheet = [[UIActionSheet alloc] initWithTitle:@"Title"
                                              delegate:self
                                     cancelButtonTitle:nil
                                destructiveButtonTitle:nil
                                     otherButtonTitles:@"Ok"];

使用@

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我已经从@Sunny shah answers解决了这个问题。我试过他的答案，但行动表上有标题。相反，我尝试使用下面的代码。标题名为单个空格

self.dobActionSheet = [[UIActionSheet alloc] initWithTitle:@" " delegate:nil cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:nil,nil];

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尝试使用[self.dobActionSheet showInView:self.view]；我不能这么做。因为此viewcontroller在第一个索引时嵌入在tabbarcontroller中。这是正确的方法吗？不管怎么说，我都试过了，但还是犯了同样的错误！！可能重复：@c0ming谢谢你的链接。我已经试过了，但对我来说不起作用。动作单显示标题。。所以我试着用单个空格作为标题。它起作用了。看看我的答案。。感谢+1为你：

actionSheet = [[UIActionSheet alloc] initWithTitle:nil
delegate:nil
cancelButtonTitle:@""
destructiveButtonTitle:nil
otherButtonTitles:nil];

self.dobActionSheet = [[UIActionSheet alloc] initWithTitle:@" " delegate:nil cancelButtonTitle:nil destructiveButtonTitle:nil otherButtonTitles:nil,nil];