ios - 测试 UNNotificationSettings

Question

测试结果始终为 0，因为 getNotificationSettingsWithCompletionHandler: block 之后的代码在 block 中设置 notificationsAlertAuthorization 值之前执行。

我该如何解决这个问题？

在 AppDelegate.h 中:

- (BOOL)testNotificationsAuthorization;

在 AppDelegate.m 中:

- (BOOL)testNotificationsAuthorization {
__block BOOL notificationsAlertAuthorization = 0;

[[UNUserNotificationCenter currentNotificationCenter] getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {
    if (settings.alertSetting == UNNotificationSettingEnabled) {
        notificationsAlertAuthorization = YES;
        NSLog(@"settings.alertSetting: YES");
    }
}];

// gets executed before notificationsAlertAuthorization is set,
// result is always NO.
if (notificationsAlertAuthorization == YES) {
    NSLog(@"Alert Authorization Granted");
    return YES;
} else {
    NSLog(@"Alert Authorization NOT Granted");
    return NO;
} }

在 View Controller 中:

- (IBAction)testForNotificationSettings:(UIButton *)sender {
BOOL result = [[[UIApplication sharedApplication] delegate] testNotificationsAuthorization];
NSLog(@"testForNotificationSettings result: %d", result);}

日志:

2016-11-20 17:18:51.221 UserNotificationsTest[11873:536763] 未授予警报授权 2016-11-20 17:18:51.222 UserNotificationsTest[11873:536763] testForNotificationSettings 结果:0 2016-11-20 17:18:51.223 UserNotificationsTest[11873:536812] settings.alertSetting: YES

Answer 1

您需要使用 CompletionHandlers 才能获得结果，因为您在 CompletionHandle 中获得 Notification 的状态，并且在获得结果之前比较它，这就是您得到错误结果的原因。

像这样改变你的方法

-(void) testNotificationsAuthorization :(void (^)(BOOL isActive))handler {
    [[UNUserNotificationCenter currentNotificationCenter] getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {
        if (settings.alertSetting == UNNotificationSettingEnabled) {
            handler(YES);
            NSLog(@"settings.alertSetting: YES");
        } else {
            NSLog(@"settings.alertSetting: NO");
            handler(NO);
        }
    }];
}

然后像这样使用它

[[[UIApplication sharedApplication] delegate] isNotificationActive:^(BOOL isActive) {
        if (isActive) {
            NSLog(@"settings.alertSetting: YES");
        } else {
            NSLog(@"settings.alertSetting: NO");
        }
    }];