UIAlertController显示UIAlertActions的空白标题

Question

最近，我终于重构了一个遗留项目，并将所有UIAlertViews和UIActionSheets变为UIAlertControllers。但我开始收到客户的问题，他们说有时候UIAlertController行动标题是空白的。就像那样：

我无法在我的设备上重现此错误，您对可能的原因有任何想法吗？

更新

我相信，该代码中包含该问题，主窗口的tintColor可能不是默认的，UIAlertController会继承它吗？

@implementation UIAlertController (WMC)

   - (void)show:(BOOL)animated {
        self.alertWindow = [[UIWindow alloc] initWithFrame:[UIScreen 
   mainScreen].bounds];
       self.alertWindow.rootViewController = [[UIViewController alloc] init];

       id<UIApplicationDelegate> delegate = [UIApplication sharedApplication].delegate;
       // Applications that does not load with UIMainStoryboardFile might not have a window property:
       if ([delegate respondsToSelector:@selector(window)]) {
           // we inherit the main window's tintColor
           self.alertWindow.tintColor = delegate.window.tintColor;
       }

       // window level is above the top window (this makes the alert, if it's a sheet, show over the keyboard)
       UIWindow *topWindow = [UIApplication sharedApplication].windows.lastObject;
       self.alertWindow.windowLevel = topWindow.windowLevel + 1;

       [self.alertWindow makeKeyAndVisible];
       [self.alertWindow.rootViewController presentViewController:self animated:animated completion:nil];
   }

   @end

Answer 1

最后，我找到了解决方案。经过一些实验，我意识到，为tintColor设置UIWindow属性会导致更改UIAlertActions中显示的所有UIWindow的tintColor。所以，我已经更改了UIAlertController扩展的代码（注意：原始代码不是我的，我在SoF找到它，感谢它的作者），我用它以这种方式呈现我的警报： / p>

#import "UIAlertController+WMC.h"

@implementation UIAlertController (Private)

@dynamic alertWindow;

- (void)setAlertWindow:(UIWindow *)alertWindow {
    objc_setAssociatedObject(self, @selector(alertWindow), alertWindow, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (UIWindow *)alertWindow {
    return objc_getAssociatedObject(self, @selector(alertWindow));
}

@end

@implementation UIAlertController (WMC)

- (void)show {
    [self show:YES];
}

- (void)show:(BOOL)animated {
    self.alertWindow = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
    self.alertWindow.rootViewController = [[UIViewController alloc] init];

    // window level is above the top window (this makes the alert, if it's a sheet, show over the keyboard)
    UIWindow *topWindow = [UIApplication sharedApplication].windows.lastObject;
    self.alertWindow.windowLevel = topWindow.windowLevel + 1;

    [self.alertWindow makeKeyAndVisible];
    [self.alertWindow.rootViewController presentViewController:self animated:animated completion:nil];
}

- (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];

    // precaution to insure window gets destroyed
    self.alertWindow.hidden = YES;
    self.alertWindow = nil;
}

我完全删除了继承主窗口tintColor的部分。这种复杂的呈现警报的方式是我项目中架构不当导航的结果。感谢所有评论员对这个问题感兴趣。

Answer 2

试试此代码

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Title" message:@"Title Message" preferredStyle:UIAlertControllerStyleActionSheet];

    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:NSLocalizedString(@"Cancel", @"Cancel action") style:UIAlertActionStyleCancel handler:^(UIAlertAction *action){
        NSLog(@"Cancle Tapped");
        [alertController dismissViewControllerAnimated:YES completion:nil];
    }];

    [alertController addAction:cancelAction];

    UIAlertAction *yesAction = [UIAlertAction actionWithTitle:NSLocalizedString(@"Yes", @"Yes action") style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){
        NSLog(@"Yes Tapped");
    }];
    [alertController addAction:yesAction];

    UIAlertAction *noAction = [UIAlertAction actionWithTitle:NSLocalizedString(@"No", @"No action") style:UIAlertActionStyleDefault handler:^(UIAlertAction *action){
        NSLog(@"No Tapped");
    }];
    [alertController addAction:noAction];
    [self presentViewController:alertController animated:YES completion:nil];