首先需要明白，GET跟POST 区别：
GET请求 ，将参数直接写在访问路径上。操作简单，不过容易被外界看到，安全性不高，地址最多255字节；POST请求，将参数放到body里面。
POST请求操作相对复杂，需要将参数和地址分开，不过安全性高，参数放在body里面，不易被捕获
同步 跟 异步区别：同步请求可以从因特网请求数据，一旦发送同步请求，程序将停止用户交互，直至服务器返回数据完成，才可以进行下一步操作，异步请求不会阻塞主线程，而会建立一个新的线程来操作，用户发出异步请求后，依然可以对UI进行操作，程序可以继续运行
以下分别介绍几种方式的使用：
1.GET 同步请求
//创建请求路径
NSString *strURL = [NSString stringWithFormat:@"http://192.168.10.252/upload/mapi/index.php?act=register&r_type=1&email=%@&password=%@&user_name=%@",@"123456@qq.com",@"123456",@"zhangsan"];
//通过url创建网络请求
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:strURL]];
NSError *error =nil;
//同步方式连接服务器
NSData *data = [NSURLConnectionsendSynchronousRequest:request returningResponse:nilerror:&error];
//json 解析返回数据
NSDictionary *dic = [NSJSONSerializationJSONObjectWithData:data options:kNilOptionserror:nil];
NSLog(@"%@",[dicobjectForKey:@"info"]);
2.post 同步请求
//通过url创建网络请求
NSString *strURL = [NSStringstringWithFormat:@"http://192.168.10.252/upload/mapi/index.php?"]; //通过url创建网络请求 NSMutableURLRequest *request = [NSMutableURLRequestrequestWithURL:[NSURLURLWithString:strURL]];
//设置请求方式也POST（默认是GET）
[request setHTTPMethod:@"POST"];
//设置请求参数 NSString *body = [NSStringstringWithFormat:@"act=%@&r_type=%d&email=%@&password=%@&user_name=%@",@"register",1,@"12345@qq.com",@"123456",@"lisi"];
//需要NSUTF8StringEncoding转码 [request setHTTPBody:[bodydataUsingEncoding:NSUTF8StringEncoding]];
//同步方式连接服务器 NSData *data = [NSURLConnectionsendSynchronousRequest:request returningResponse:nilerror:nil];
//json 解析返回数据 NSDictionary *dic = [NSJSONSerializationJSONObjectWithData:data options:kNilOptionserror:nil]; NSLog(@"%@",[dicobjectForKey:@"info"]);
3.GET 异步代码块请求
NSString *strURL = [NSString stringWithFormat:@"http://192.168.10.252/upload/mapi/index.php?act=register&r_type=1&email=%@&password=%@&user_name=%@",@"123456@qq.com",@"123456",@"zhangsan"];
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:strURL]];
NSError *error = nil;
NSLog(@"111==%@",[NSThread currentThread]);
//创建异步代码方式
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue new] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) { NSLog(@"222==%@",[NSThread currentThread]);
//网络请求结束
NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil];
NSLog(@"%@",[dic objectForKey:@"info"]);
//回到主线程，去刷新界面//
self performSelectorOnMainThread:<#(SEL)#> withObject:<#(id)#> waitUntilDone:<#(BOOL)#> dispatch_async(dispatch_get_main_queue(), ^{ //回主线程要做的事情 }); }];
4.POST 异步代码块请求
NSString *strURL = [NSStringstringWithFormat:@"http://192.168.10.252/upload/mapi/index.php?"]; NSMutableURLRequest *request = [NSMutableURLRequestrequestWithURL:[NSURLURLWithString:strURL]];
[request setHTTPMethod:@"POST"];
[request setTimeoutInterval:10];
NSString *body = [NSStringstringWithFormat:@"act=%@&r_type=%d&email=%@&password=%@&user_name=%@",@"register",1,@"12345@qq.com",@"123456",@"lisi"];
[request setHTTPBody:[bodydataUsingEncoding:NSUTF8StringEncoding]]; [NSURLConnectionsendAsynchronousRequest:request queue:[NSOperationQueuemainQueue] completionHandler:^(NSURLResponse *response,NSData *data, NSError *connectionError) { NSDictionary *dic = [NSJSONSerializationJSONObjectWithData:data options:kNilOptionserror:nil]; NSLog(@"%@",[dicobjectForKey:@"info"]); }];
5. 异步代理请求用代理需要导入协议：NSURLConnectionDataDelegate@interface ViewController ()NSString *strURL = [NSString stringWithFormat:@"http://192.168.10.252/upload/mapi/index.php?"];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:strURL]];
[request setHTTPMethod:@"POST"];
NSString *body = [NSString stringWithFormat:@"act=%@&r_type=%d&email=%@&password=%@&user_name=%@",@"register",1,@"12345@qq.com",@"123456",@"lisi"];
[request setHTTPBody:[body dataUsingEncoding:NSUTF8StringEncoding]];
//使用代理的方式做网络请求
[NSURLConnection connectionWithRequest:request delegate:self];
#pragma mark -- 网络请求代理方法实现
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;
{
NSLog(@"网络请求总数据量,这个只执行一次");
infoData = [[NSMutableData alloc]init];
}
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
NSLog(@"这个方法会执行多次！");
[infoData appendData:data];
}
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(@"网络请求结束！！！");
NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:infoData options:kNilOptions error:nil];
NSLog(@"%@",dict);
NSLog(@"%@",dict[@"info"]);
}
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(@"网络请求失败。失败原因%@",error);
}
