iOS ARC UIAlertView 内存泄漏

Question

我有一个简单的方法来显示带有文本字段的 AlertView。仪器显示内存泄漏。请解释一下。

- (void)method {
NSString *value = [[NSUserDefaults standardUserDefaults] valueForKey:@"key"];
if (value == nil) {

    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Title" message:@"message" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];

    alertView.tag = 101;
    alertView.alertViewStyle = UIAlertViewStylePlainTextInput;
    UITextField *txtGroup = [alertView textFieldAtIndex:0];
    [txtGroup becomeFirstResponder];

    [alertView show];
    alertView = nil;
}
}

请查看 Instruments 的截图：

Answer 1

您需要将 alertView 创建为：

static UIAlertView *alertView = nil;

if (!alertView){
   alertView = [[UIAlertView alloc] initWithTitle:@"Title" message:@"message" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
}