IOS 学习 gei post 同步 异步方法

@implementation ViewController

(void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

// NSURL *url = [NSURL URLWithString:@”http://www.baidu.com“];

//

// //第一个参数请求访问路径 第二个参数缓存协议 第三个参数 网络请求超时时间

// NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];

//

// [request setHTTPMethod:@”POST”];

// NSString *str = @”type=focus-c”;

// NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];

// [request setHTTPBody:data];

//

// //使用NSURLConnection实现http通信,NSURLConnection创建成功后，就创建了一个http链接

// NSData *received = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

//

// //将返回的数据转成string

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

//

// NSLog(@”%@”,str1);

NSURL *url =[NSURL URLWithString:@"http://apis.baidu.com/apistore/weatherservice/citylist"];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL:url cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:10];
[request setHTTPMethod:@"POST"];
NSString *str = @"type=focus-c";
NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];
[request setHTTPBody:data];
NSURLConnection *connection = [[NSURLConnection alloc]initWithRequest:request delegate:self];

}

//当接受到网络反馈时执行

-(void)connection:(NSURLConnection )connection didReceiveResponse:(NSURLResponse )response

{

self.receiveData = [NSMutableData data];

}

//当接受到网络数据时执行

-(void)connection:(NSURLConnection )connection didReceiveData:(NSData )data

{

self.receiveData = data;

}

//当一系列动作结束后执行

-(void)connectionDidFinishLoading:(NSURLConnection *)connection

{

NSString *receiveStr = [[NSString alloc]initWithData:self.receiveData encoding:NSUTF8StringEncoding];

NSLog(@"%@",receiveStr);

}

//当链接失败执行该方法

-(void)connection:(NSURLConnection )connection didFailWithError:(NSError )error

{

NSLog(@”error%@”,[error localizedDescription]);

}

(void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end