block OC 用法

block OC 用法 函数指针

ex1:

typedef int(^func_aaa)(id parameter);
- (void)testFunc{
    func_aaa test;
    test = ^(NSNumber* qq){
        PKLog(@"val: %@",qq);
        return 456;
    };
    int a = test([NSNumber numberWithInt:123]);
    PKLog(@"%d",a);
}

ex1_log:

2016-04-07 17:00:19.028 djcars[5566:210891] 123
2016-04-07 17:00:25.356 djcars[5566:210891] val: 123
2016-04-07 17:00:28.326 djcars[5566:210891] 456

ex2 (在循环内使用Block,block会引用循环体内的值)

typedef int(^func_aaa)(id parameter);
- (void)testFunc{
    NSMutableDictionary *mulAry = [[NSMutableDictionary alloc]init];
    for (int i = 0 ; i < 10; i++) {
        func_aaa test;
        test = ^(NSNumber* qq){
                PKLog(@"val: %@",qq);
                return i+10;
            };
        [mulAry setObject:test forKey:[NSString stringWithFormat:@"keyNo_is%d",i]];
    }
    PKLog(@"%@",mulAry);
    NSInteger i = 0;
    for (func_aaa obj in [mulAry allValues]) {
        int v = obj([NSNumber numberWithInteger:i++]);
        PKLog(@"%d",v);
    }
}

ex2_log:

2016-04-08 10:36:46.129 djcars[2958:46438] val: 0
2016-04-08 10:36:46.129 djcars[2958:46438] 19
2016-04-08 10:36:46.129 djcars[2958:46438] val: 1
2016-04-08 10:36:46.129 djcars[2958:46438] 17
2016-04-08 10:36:46.129 djcars[2958:46438] val: 2
2016-04-08 10:36:46.129 djcars[2958:46438] 15
2016-04-08 10:36:46.130 djcars[2958:46438] val: 3
2016-04-08 10:36:46.130 djcars[2958:46438] 13
2016-04-08 10:36:46.130 djcars[2958:46438] val: 4
2016-04-08 10:36:46.130 djcars[2958:46438] 11
2016-04-08 10:36:46.130 djcars[2958:46438] val: 5
2016-04-08 10:36:46.130 djcars[2958:46438] 18
2016-04-08 10:36:46.130 djcars[2958:46438] val: 6
2016-04-08 10:36:46.130 djcars[2958:46438] 16
2016-04-08 10:36:46.130 djcars[2958:46438] val: 7
2016-04-08 10:36:46.131 djcars[2958:46438] 14
2016-04-08 10:36:46.131 djcars[2958:46438] val: 8
2016-04-08 10:36:46.131 djcars[2958:46438] 12
2016-04-08 10:36:46.131 djcars[2958:46438] val: 9
2016-04-08 10:36:46.131 djcars[2958:46438] 10

ex3 （Block 订阅为类型）:

typedef void(^WACallback)(id parameter);

@property(nonatomic, strong)WACallback callbackBlock;

WACallback callbackBlock = ^(id returnValue) {
                    returnValue = returnValue ? : NSNull.null;
                    NSDictionary *result = @{@"result": returnValue};
                    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:result options:0 error:nil];
                    NSString *json = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
                    NSString *javascript = [NSString stringWithFormat:@"WebApiCore.invokeWebMethod(\"%@\", %@.result);", callback, json];
                    [webView stringByEvaluatingJavaScriptFromString:javascript];
                };

ex4 (函数内，带参数写法)

void (^updateStringBlock)(nsstring* str1,nsstring* str2) = ^(nsstring* str1,nsstring* str2){

};

ex5 (替代代理写法，要注意强弱引用导致控制器不释放)

@property (nonatomic, copy) void (^onMoreClickBlock)(id obj);

block OC 函数回调语法

//参考语法
+ (void)updataAiQiYiVideo:(NSString*)xxx succeed:(void (^)(NSString* xxx1,NSString* xxx2))succeed fail:(void (^)())fail;

// 上传视频
+ (void)updataAiQiYiVideo:(NSString*)dstPath succeed:(void (^)(NSString* fileId,NSString* dstPath))succeed fail:(void (^)())fail{
    NSDictionary* params = [NSDictionary dictionaryWithObjectsAndKeys:@"gameChatTest",@"file_name",@"just_test",@"description",nil];
    
    VCOPClient *client = [PKAiQiYiTool VCOPClientInstance];
    [PKAiQiYiTool enterPrise];
    [client uploadVideoWithContentOfFile:dstPath fileType:@"mp4" params:params threadCount:3 willStart:^(NSString* filePath, NSString *fileId) {
        NSLog(@"fileId=%@",fileId);
    } progress:^(NSString *fileId, NSNumber *percent) {

    } complete:^(NSString* fileId, NSDictionary *videoInfo) {
       
		 //block 成功回调
        succeed(fileId,dstPath);
        PKLog(@"complete fileId=%@",fileId);
    } failure:^(NSString* fileId, NSError *error) {
    
		 //block 失败回调
        fail();
    }];
    
}