NSURLConnection

NSURLConnection的GET请求：

　　- 发送同步请求

// 0.请求路径
NSURL *url = [NSURL URLWithString:@"http://XXX.XXX.XXX.XXX:32812/login?username=123&pwd=345"];

// 1.创建请求对象
NSURLRequest *request = [NSURLRequest requestWithURL:url];

// 2.发送请求
// sendSynchronousRequest阻塞式的方法，等待服务器返回数据

NSHTTPURLResponse *response = nil;
NSError *error = nil;

NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

// 3.解析服务器返回的数据（解析成字符串）
NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@ %@", string, response.allHeaderFields);

　　- 发送异步请求

// 0.请求路径
NSURL *url = [NSURL URLWithString:@"http://XXX.XXX.XXX.XXX:32812/login?username=123t&pwd=123"];

// 1.创建请求对象
NSURLRequest *request = [NSURLRequest requestWithURL:url];

// 2.发送请求
[NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
// 请求完毕会来到这个block
// 3.解析服务器返回的数据（解析成字符串）
NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@", string);
//        NSHTTPURLResponse *r = (NSHTTPURLResponse *)response;
//
//        NSLog(@"%zd %@", r.statusCode, r.allHeaderFields);
}];

　　

　　- 代理方式<NSURLConnectionDataDelegate>

- (void)delegateAysnc
{
// 0.请求路径
NSURL *url = [NSURL URLWithString:@"http://XXX.XXX.XXX.XXX:32812/login?username=122&pwd=123"];

// 1.创建请求对象
NSURLRequest *request = [NSURLRequest requestWithURL:url];

// 2.创建连接对象
//    [[NSURLConnection alloc] initWithRequest:request delegate:self];

//    NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO];
//    [conn start];

[NSURLConnection connectionWithRequest:request delegate:self];

// 取消
//    [conn cancel];
}

#pragma mark - <NSURLConnectionDataDelegate> -- being
/**
* 接收到服务器的响应
*/
- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response
{
// 创建data对象
self.responseData = [NSMutableData data];
NSLog(@"didReceiveResponse");
}

/**
* 接收到服务器的数据（如果数据量比较大，这个方法会被调用多次）
*/
- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
// 不断拼接服务器返回的数据
[self.responseData appendData:data];
NSLog(@"didReceiveData -- %zd", data.length);
}

/**
* 服务器的数据成功接收完毕
*/
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSLog(@"connectionDidFinishLoading");
NSString *string = [[NSString alloc] initWithData:self.responseData encoding:NSUTF8StringEncoding];
NSLog(@"%@", string);

self.responseData = nil;
}

/**
* 请求失败（比如请求超时）
*/
- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error
{
NSLog(@"didFailWithError -- %@", error);
}
#pragma mark - <NSURLConnectionDataDelegate> -- end

　　- POST请求

1.请求路径
NSURL *url = [NSURL URLWithString:@"http://XXX.XXX.XXX.XXX:32812/login"];

// 2.创建请求
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
// 更改请求方法
request.HTTPMethod = @"POST";
// 设置请求体
request.HTTPBody = [@"username=123&pwd=123" dataUsingEncoding:NSUTF8StringEncoding];
// 设置超时(5秒后超时)
request.timeoutInterval = 5;
// 设置请求头
//    [request setValue:@"iOS 9.0" forHTTPHeaderField:@"User-Agent"];

// 3.发送请求
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
if (connectionError) { // 比如请求超时
NSLog(@"----请求失败");
} else {
NSLog(@"------%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);
}
}];

- 总结下带中文的GET和POST

- (void)post
{
// 0.请求路径
NSString *urlStr = @"http://XXX.XXX.XXX.XXX:32812/login2";
NSURL *url = [NSURL URLWithString:urlStr];

// 1.创建请求对象
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
request.HTTPMethod = @"POST";
request.HTTPBody = [@"username=POST请求&pwd=123" dataUsingEncoding:NSUTF8StringEncoding];

// 2.发送请求
[NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
// 3.解析服务器返回的数据（解析成字符串）
NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@", string);
}];
}

- (void)get
{
// 0.请求路径
NSString *urlStr = @"http://XXX.XXX.XXX.XXX:32812/login2?username=GET请求&pwd=123";
// 将中文URL进行转码
urlStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:urlStr];

// 1.创建请求对象
NSURLRequest *request = [NSURLRequest requestWithURL:url];

// 2.发送请求
[NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
// 3.解析服务器返回的数据（解析成字符串）
NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"%@", string);
}];
}