IOS-NSNotification的简单使用流程：

NSNotification的简单使用流程（例子）如下：
1、在viewDidLoad添加：
- (void)viewDidLoad

{//添加如下
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(showAlertView:) name:@"showAlertView" object:nil];
}
2、.m文件中添加：（例子如下）
- (void)showAlert:(NSString *)msg

{

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Note" message:msg delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];

[alert show];

[alert release];

}

- (void)showAlertView:(NSNotification *)notification

{

if (self.pickerView.getIndex <= 2) {

[self showAlert:@"Number of players has reached its minimum."];

}else if (self.pickerView.getIndex >= 50) {

[self showAlert:@"Number of players has reached its maximum."];

}

}
3、在需要响应并发出通知处，调用如下方法：
- (void)sendNotification{

if ([self getIndex] >= 50)

[[NSNotificationCenter defaultCenter] postNotificationName:@"showAlertView" object:nil];

if ([self getIndex] <= 2)

[[NSNotificationCenter defaultCenter] postNotificationName:@"showAlertView" object:nil];

}
4、在viewDidUnLoad添加：
[[NSNotificationCenter defaultCenter] removeObserver:self name:@"showAlertView" object:nil];
5、在dealloc中添加：
[[NSNotificationCenter defaultCenter] removeObserver:self name:nil object:nil];

分类: IOS随笔小记