ios - NSNotificationCenter 和 mapType

Question

我正在尝试从另一个 ViewController 更改 mapType，但它只显示 HybridType。无论按下分段控件上的按钮，任何其他 mapType 都不会改变。我究竟做错了什么？提前谢谢你..

-(void) receiveTestNotification:(NSNotification *) notification{
_mapView.delegate = self;
if ([[notification name] isEqualToString:@"TestNotification"]) {
    _mapView.mapType = MKMapTypeStandard;
    NSLog(@"Successfully changed maptype");
}
if ([[notification name] isEqualToString:@"TestNotification2"]) {
    _mapView.mapType = MKMapTypeSatellite;
    NSLog(@"Successfully changed maptype");
}
if ([[notification name] isEqualToString:@"TestNotification3"]) {
    _mapView.mapType = MKMapTypeHybrid;
    NSLog(@"Successfully changed maptype");
}

}

在 ViewDidLoad 中:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveTestNotification:) name:@"TestNotification" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveTestNotification:) name:@"TestNotification2" object:nil];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveTestNotification:) name:@"TestNotification3" object:nil];

在我的另一个 viewController 中:

- (IBAction)segmentedControl:(id)sender {

switch (((UISegmentedControl *) sender).selectedSegmentIndex) {
    case 0:
        [[NSNotificationCenter defaultCenter] postNotificationName:@"TestNotification" object:self];
        [self dismissModalViewControllerAnimated:YES];
    case 1:
        [[NSNotificationCenter defaultCenter] postNotificationName:@"TestNotification2" object:self];
        [self dismissModalViewControllerAnimated:YES];
    case 2:
        [[NSNotificationCenter defaultCenter] postNotificationName:@"TestNotification3" object:self];
        [self dismissModalViewControllerAnimated:YES];
}
}

Answer 1

一切似乎都很好。检查分段控件中的所有 iboutlet 和日志在这种情况下可能更有帮助。另一件事你应该使用 break;在开关案例中声明，否则它会继续执行下面的代码，所以当你想发送 TestNotification 时，它也会发送下面的其他两个通知。