上一章我们讲了页面传值的两种方法属性传值和代理传值，这一章继续讲解其他传值方法
1.block传值
如要将B页面的值传到A页面，在B页面做一下设置
typedef void (^peopleMessage)(NSString *str);
@property (nonatomic, copy) peopleMessage block;
在B页面返回A页面的方法里
-(void)showMyBlock{
self.block(@”我是Block传值”);
[self dismissViewControllerAnimated:YES completion:nil];
}
在A试图显示，回调block
- (void)showSecondWithBlock:(UIbutton)btn{
SecondViewController *second =[[SecondViewController alloc]initWithNibName:@'SecondViewController'bundle:nil];
[self presentViewController:second animated:YES completion:nil];
second.block = ^(NSString *str){
NSLong(@”%@”,str)
};
}
2.通知传值
通知传值分两种情况，一是传递字典，二是传递数组
一：传递字典
在A页面的控制器中，注册通知：
- (void)viewDidLoad{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(nameChange:) name:@"tongzhi" object:nil];
}
-(void)nameChange::(NSNotification*)notification{
NSDictionary *dic = [notification userInfo];
NSLong(@"%@", dic[@"name"]);
}
在B页面返回A页面的方法里发送通知
- (void)postNotification {
[[NSNotificationCenter defaultCenter] postNotificationName:@"tongzhi" object:self userInfo:@{@"name":我 是通知传值}];
[self dismissViewControllerAnimated:YES completion:nil];
}
通知不使用时要销毁
-(void)dealloc{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
二：传递数组
- (void)viewDidLoad{
[super viewDidLoad];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(nameChange:)name:@"area" object:nil];
}
-(void)nameChange::(NSNotification*)notification{
NSArray *arr = [notification object];
NSLong(@"%@", arr);
NSLog(@"%@",[arr objectAtIndex:0]);
NSLog(@"%@",[arr objectAtIndex:1]);
NSLog(@"%@",[arr objectAtIndex:2]);
}
在B页面返回A页面的方法里发送通知
- (void)postNotification {
NSArray *arr = [NSArray arrayWithObjects:@"北京",@"上海",@"深圳",nil];
[[NSNotificationCenter defaultCenter]postNotificationName:@"area"object:arr];
[self dismissViewControllerAnimated:YES completion:nil];
}
通知不使用时要销毁
-(void)dealloc{
[[NSNotificationCenter defaultCenter] removeObserver:self];
}