day1

NSURL *url = [NSURL URLWithString:sting];
NSURLRequest *request = [NSURLRequest requestWithURL];
同步请求
NSError *error = nil;
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
异步请求 代理
[NSURLConnection connectionWithRequest:request delegate:self];
回调 NSURLConnectionDataDelegate；
所有方法
-(void)connection:(NSConnection *)connection didReceiveResponse:(NSURLResponse *)response;
_receiveData.length = 0;
 [response suggestedFilename];
//资源名称
NSString *str = [NSString stringWithCString:[fileName cStringUsingEncoding:NSUTF8StringEncoding] encoding:NSUTF8StringEncoding];
资源大小
[response expectedContentLength];
 didReceiveData;
  [_receivedData appendData:data];
//进度条下载进度
float percent = (float)_receivedData.length / (float)_fileSize;
 _progress.progress = percent;
didFinishLoading;
didFailWithError;
  /**
     * NSTimer
     */
    _timer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:@selector(updateSpeed) userInfo:nil repeats:YES];
[_time invalidate];
JSON解析
JSON((JavaScript Object Notation)
SBJson 是 Objective-C 实现的一个 JSON 解析器和生成器。
SBJson 是中国人人写的，你是SB吗。
第三方的开源数据;
json的解析
在arc模式下将Compile Sources所有文件更改为-fno-objc-arc;
在didFinishLoading中
    NSString *strContent = ［NSString alloc] initWithData:_receiveData encoding:NSUTF8StringEncoding];
//文件中获取资源
NSString *path = ［NSBundle mainBundle]pathForReSource:@"jsonData" ofType:@"txt"];
NSString *string = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
导入头文件NSString +SBJson；
字典存储数据
NSDictionary *dic =[strContent JSONValue];
NSArray *array = [dic objectForKey:@"string"];//根据具体的数据结构进行存储;