//第一步，创建URL 

NSURL *urls = [NSURLURLWithString:url];

url  为请求链接

//    //第二步，创建请求

NSMutableURLRequest*request= [[NSMutableURLRequestalloc]initWithURL:urls cachePolicy:NSURLRequestUseProtocolCachePolicytimeoutInterval:10];

[request setHTTPMethod:@"POST"];//设置请求方式为POST，默认为GET

NSString *str = [NSStringstringWithFormat:@"usere=%@&pwd=%@",zhStr,mmStr];//设置参数 

    NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];

    [request setHTTPBody:data];

//    //第三步，连接服务器

    NSData *received = [NSURLConnectionsendSynchronousRequest:request returningResponse:nilerror:nil];

//转换格式NSString//    

NSString *str1 = [[NSStringalloc]initWithData:received encoding:NSUTF8StringEncoding];

//   转换格式NSDictionary

NSDictionary*jsonDict=[NSJSONSerializationJSONObjectWithData:receivedoptions:NSJSONReadingMutableLeaveserror:nil];