#import
@interfaceViewController :UIViewController
//block 定义 无返回值 传值obj
typedefvoid(^myblock)(idobj);
-(void)creatandblock:(myblock)block;
@end
@interfaceViewController()
@property(nonatomic,assign)intnumber;
//定义一个返回值为Void，名为blockBack的Block。传值为字符串。
@property(nonatomic,copy)void(^blockBack)(NSString*valuename);
@end
//定义block
typedefvoid(^myblock)(idobj);
@implementationViewController
//添加Block的类型的进行传值
-(void)creatandblock:(myblock)block
{
}
- (void)viewDidLoad {
[superviewDidLoad];
[selfcreatNSstring:@"xiao"andBlock:^(idobj) {
obj =@"abc";
}];
}
-（void)creatwithBlock:(myblock)block
{
}
-(void)creatNSstring:(NSString*)name andBlock:(myblock)block
{
block(@"acb");
}
- (void)didReceiveMemoryWarning {
[superdidReceiveMemoryWarning];
}
@end
在iOS 编程中发现Capturng 'self' strongly in this block is likely to lead to a retain cycle 的警告，告诉其，造成的是Block代码块的循环引用。
使用方法
__weaktypeof(self) weakself =self;
self.popView.selectRowAnIndex= ^(NSIntegerindex)
{
NSString*str = weakself.array[index];
NSLog(@"%@",str);
};
就是将self用弱引用的weakself替代。
主要造成循环引用的问题是 当前类调用Block ,block内部还有当前类，就会造成循环引用，可以将当前的类用__weak typeof(当前类) weak+当前类 = 当前类
void (^dealingResult)(NSArray *)= ^(NSArray *statues){
设计的一个block调用直接dealingResult();返回值为void
};
