Objective-C中block的声明

深入Objective-C block 捕获变量

声明

int (^addNumber)(int) = ^(int number){
        return number +2;
 };
NSLog(@"%i",addNumber(1));
void (^printBlock)(void) = ^() {
       NSLog(@"it is a block");
};
printBlock();

成员变量

typedef void (^CompleteBlock)(NSString * string);
@property(nonatomic ,copy)void (^handler)(void);
@property(nonatomic ,copy)CompleteBlock completeblock;
self.handler();
self.handler = ^{
};

参数

[self block:^NSString *(NSInteger number) {
        number ++;
        return [@"" stringByAppendingFormat:@"%ld",(long)number];
 }];
-(void)block:(NSString *(^)(NSInteger number))block
{
    NSString * str =  block(2);
    NSLog(@"%@",str);
}
[self block1:^(NSInteger number) {
 }];
-(void)block1:(void(^)(NSInteger number))block
{
    block(2);
}