摘要：
准备URL NSString *urlStr = self.textField.text;根据URL来准备一个请求对象 NSURL *url = [NSURL URLWithString:urlStr];发送请求 NSURLRequest *request = [NSURLRequest reque... 阅读全文
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概念:如何将NSString转化成NSData(将字符串转化成二进制数据)NSString *str = @"ABCDE"; NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding]; NSLog(@"%d",data.len... 阅读全文
摘要：
- (IBAction)blockQueue:(UIButton *)sender { NSOperationQueue *queue = [[NSOperationQueue alloc]init]; NSBlockOperation * operation = [NSBloc... 阅读全文
摘要：
创建NSOperationQueue 对象NSOperationQueue *queue = [[NSOperationQueue alloc]init];创建NSInvocationOperation对象NSInvocationOperation *operation = [[NSInvocati... 阅读全文