iphone - UIAlertView 无法显示并导致 “EXC_BAD_ACCESS” 错误

Question

按下键盘上的返回按钮时会调用一个方法。调用另一个返回整数的方法后，将根据该整数创建一条消息。然后该消息被传递到 UIAlterView 并显示给用户。该警报没有任何选项(因此我不调用委托(delegate))，而只是通知用户发生了什么。

编辑:下面是完整的方法(之前显示的部分方法)。当我注释掉 UIAlertView 之前的所有内容并替换字符串 @"test"而不是传递消息时，警报将成功显示。我的结构是否没有正确处理内存？

- (IBAction)joinButton {
    struct userInfo localUser;

    [emailAddress resignFirstResponder];

    //convert textField text to char array in structure
    localUser.firstName = [self convertStringtoCharArray:firstName.text];
    localUser.lastName = [self convertStringtoCharArray:lastName.text];
    localUser.username = [self convertStringtoCharArray:username.text];
    localUser.email = [self convertStringtoCharArray:emailAddress.text];
    localUser.ipAddress = [self convertStringtoCharArray:localIPAddress.text];
    localUser.latitude = currentLocation.coordinate.latitude;
    localUser.longitude = currentLocation.coordinate.longitude;

    //pass structure to be sent over socket
    int result = [myNetworkConnection registerWithServer:&localUser];

    NSString *message = nil;

    //process result of sending attempt
    if (result == 0) {
        //registration succesful
        message = [NSString stringWithString:@"Registration successful"];
    } else if (result == 1) {
        //server unavailable
        message = [NSString stringWithString:@"Server unavailable. Please check your wi-fi settings and try again."];
    } else if (result == 2) {
        //unable to establish connection
        message = [NSString stringWithString:@"Unable to communicate with server. Please check your wi-fi settings and try again."];
    } else if (result == 3) {
        //username already in use
        message = [NSString stringWithString:@"Username in use. Try another username."];
    }

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Registration"
                                                    message:message
                                                   delegate:nil 
                                          cancelButtonTitle:@"Ok" 
                                          otherButtonTitles:nil];

    [alert show];
    [alert release];
}

当我执行代码时，iPhone 变灰，就像即将显示警报但崩溃了。我在控制台中收到 EXC_BAD_ACCESS 错误。我是否没有正确发布警报或消息？这是控制台输出:

Program received signal:  “EXC_BAD_ACCESS”.
(gdb) backtrace
#0  0x30011944 in objc_msgSend ()
#1  0x3054803e in NSPopAutoreleasePool ()
#2  0x3054c808 in -[NSAutoreleasePool release] ()
#3  0x30936ac4 in _UIApplicationHandleEvent ()
#4  0x3204696c in PurpleEventCallback ()
#5  0x30254a76 in CFRunLoopRunSpecific ()
#6  0x3025416a in CFRunLoopRunInMode ()
#7  0x320452a4 in GSEventRunModal ()
#8  0x308f037c in -[UIApplication _run] ()
#9  0x308eea94 in UIApplicationMain ()
#10 0x000020bc in main (argc=1, argv=0x2ffff508) at /Users/reu2009/Documents/iPhone Development/Development/BuddyTracker/main.m:14
(gdb) frame 10
#10 0x000020bc in main (argc=1, argv=0x2ffff508) at /Users/reu2009/Documents/iPhone Development/Development/BuddyTracker/main.m:14 14       int retVal = UIApplicationMain(argc, argv, nil, nil);

编辑:删除了[message release];并根据答案使用[NSString stringWithString];分配了字符串。

Answer 1

我遇到了这样的问题...我从后台线程调用 uiAlertView ....从主线程调用它