【读书笔记】iOS-GCD-使用方法

代码：

 

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        
        //在后台进行网址的解析操作
        NSURL * url = [NSURL URLWithString:@"http://www.baidu.com"];
        NSError * error;
        NSString * data = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
        if (data != nil) {
            dispatch_async(dispatch_get_main_queue(), ^{
                //成功，跳转回主界面
                NSLog(@"call back, the data is: %@", data);
            });
        } else {
            //失败，返回失败提示。
            NSLog(@"error when download:%@", error);
        }
    });
    
}

 

 

输出：

2015-07-15 21:51:37.902 CGD-使用[1719:81744] call back, the data is: "Content-Type" content="text/html; charset=utf-8" />'margin:0px;overflow-x:hidden;overflow-y:hidden;'>

 

 

参考资料

http://www.cnblogs.com/pure/archive/2013/03/31/2977420.html