NSNotificationCenter和mapType

Question

我正在尝试从另一个ViewController更改mapType，但它只显示HybridType。无论我的分段控件上的按钮被按下，任何其他mapType都不会改变。我做错了什么？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。在这种情况下，检查分段控件和日志中的所有iboutlets可能会更有帮助。还有一件事，你应该在切换的情况下使用break；语句，否则它会继续执行下面的代码，所以当你想要发送TestNotification时，它还会发送下面的另外两个通知。

Answer 2

你错过了开关/中的"break“。