UIAlertView崩溃

Question

我在提示用户

时收到以下异常

0  CoreFoundation   __exceptionPreprocess + 130
1  libobjc.A.dylib  objc_exception_throw + 38
2  CoreFoundation   -[NSObject(NSObject) doesNotRecognizeSelector:] + 202
3  CoreFoundation   ___forwarding___ + 706
4  CoreFoundation   _CF_forwarding_prep_0 + 24
5  UIKit            -[_UIModalItem setMessage:] + 40
6  UIKit            -[_UIModalItem initWithTitle:message:otherButtonTitles:completion:delegate:] + 102
7  UIKit            +[_UIModalItem modalItemWithType:title:message:buttonTitles:completion:] + 76
8  UIKit            -[UIAlertView _modalItemForNeueCompatibility] + 362
9  UIKit            -[UIAlertView popupAlertAnimated:animationType:atOffset:] + 56
10 UIKit            -[UIAlertView popupAlertAnimated:animationType:] + 34

我在一个实用程序类

中的方法中编写了Alert视图代码

+(void)showAlertWithTitle:(NSString*)title message:(NSString*)msg cancelButtonTitle:(NSString*)canceltitle confirmBtnTitle:(NSString*)cnftitle andTag:(int)alertTag  andDelegate:(id)ref{

    UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:title message:msg delegate:ref cancelButtonTitle:canceltitle otherButtonTitles:cnftitle, nil];
    alertView.tag = alertTag;
    [alertView show];
}

Answer 1

您必须从主线程显示警报视图。如果可以从任何其他队列或线程调用这段代码，请将其包装在对dispatch_async的调用中：

dispatch_async(dispatch_get_main_queue(), ^
{
    UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:title message:msg delegate:ref cancelButtonTitle:canceltitle otherButtonTitles:cnftitle, nil];
    alertView.tag = alertTag;
    [alertView show];
});