iOS 網絡：HTTP 請求

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HTTP請求

1. NSURLConnectiong

1.同步GET請求

// 1.創建請求路徑(url)
NSURL *url = [NSURL URLWithString:@""];

// 2.通過請求路徑(url)創建請求對象(request)
NSURLRequest *request = [NSURLRequest requestWithURL:url];

// 3.向服務器發送同步請求(data)
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
// sendSynchronousRequest阻塞式的方法，等待服務器返回數據

// 4.解析服務器返回的數據(解析成字符串)
NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];

2. 異步GET請求

// 1.創建請求路徑(url)
NSURL *url = [NSURL URLWithString:@""];

// 2.通過請求路徑(url)創建請求對象(request)
NSURLRequest *request = [NSURLRequest requestWithURL:url];

// 3.向服務器發送異步請求
[NSURLConnection sendAsynchronousRequest:request queue:[[NSOperationQueue alloc] init] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
    // 請求完畢會來到這個block

    // 4.解析服務器返回的數據（解析成字符串）
    NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
    NSLog(@"%@", string);
}];

3. 通過代理髮送異步請求

// 1.創建請求路徑(url)
NSURL *url = [NSURL URLWithString:@""];

// 2.通過請求路徑(url)創建請求對象(request)
NSURLRequest *request = [NSURLRequest requestWithURL:url];

// 3.通過代理創建連接對象
[NSURLConnection connectionWithRequest:request delegate:self];

// [[NSURLConnection alloc] initWithRequest:request delegate:self];

// NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO];
// startImmediately:是否立即發送請求

// 開始發送請求
// [conn start];

// 取消發送請求
// [conn cancel];

• 代理需要實現的方法：

#pragma mark - <NSURLConnectionDataDelegate>

// 接收到服務器的響應
-(void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response;

// 接收到服務器的數據（如果數據量比較大，這個方法會被調用多次）
-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data; // 不斷拼接服務器返回的數據

// 服務器的數據成功接收完畢
-(void)connectionDidFinishLoading:(NSURLConnection *)connection;

// 請求失敗（比如請求超時）
-(void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error;

4. 同步POST請求

// 1.創建請求路徑(url)
NSURL *url = [NSURL URLWithString:@""];

// 2.通過請求路徑(url)創建請求對象(request)
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
// 更改請求方法
request.HTTPMethod = @"POST";
// 設置請求體
request.HTTPBody = [@"" dataUsingEncoding:NSUTF8StringEncoding];
// 設置超時(5秒後超時)
request.timeoutInterval = 5;
// 設置請求頭(非必要，看情況)
//    [request setValue:@"iOS 9.0" forHTTPHeaderField:@"User-Agent"];

// 3.向服務器發送同步請求
[NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

5. 異步POST請求

// 1.創建請求路徑(url)
NSURL *url = [NSURL URLWithString:@""];

// 2.通過請求路徑(url)創建請求對象(request)
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
// 更改請求方法
request.HTTPMethod = @"POST";
// 設置請求體
request.HTTPBody = [@"" dataUsingEncoding:NSUTF8StringEncoding];
// 設置超時(5秒後超時)
request.timeoutInterval = 5;
// 設置請求頭
// [request setValue:@"iOS 9.0" forHTTPHeaderField:@"User-Agent"];

// 3.向服務器發送異步請求
[NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
    if (connectionError) { // 比如請求超時
        NSLog(@"----請求失敗");
    } else {
        NSLog(@"------%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding]);
    }
}];

6. NSURLConnection 中文URL處理

NSString *urlStr = @"";
// 將中文URL進行轉碼
urlStr = [urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *url = [NSURL URLWithString:urlStr];

2. NSURLSession

GET請求

// 第一種GET請求
// 獲得NSURLSession對象
NSURLSession *session = [NSURLSession sharedSession];

// 創建任務
NSURLSessionDataTask *task = [session dataTaskWithRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@""]] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
    NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
}];

// 啓動任務
[task resume];

// 第二種GET請求
// 獲得NSURLSession對象
NSURLSession *session = [NSURLSession sharedSession];

// 創建任務
NSURLSessionDataTask *task = [session dataTaskWithURL:[NSURL URLWithString:@""] completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
    NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
}];

// 啓動任務
[task resume];

POST請求

// 獲得NSURLSession對象
NSURLSession *session = [NSURLSession sharedSession];

// 創建請求
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@""]];
request.HTTPMethod = @"POST"; // 請求方法
request.HTTPBody = [@"" dataUsingEncoding:NSUTF8StringEncoding]; // 請求體

// 創建任務
NSURLSessionDataTask *task = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
    NSLog(@"%@", [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:nil]);
}];

// 啓動任務
[task resume];

通過代理髮送請求

// 獲得NSURLSession對象
NSURLSession *session = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:[[NSOperationQueue alloc] init]];

// 創建任務
NSURLSessionDataTask *task = [session dataTaskWithRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@""]]];

// 啓動任務
[task resume];

• 代理需要實現的方法：

#pragma mark - <NSURLSessionDataDelegate>

// 1.接收到服務器的響應
-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler
{
    // 允許處理服務器的響應，纔會繼續接收服務器返回的數據
    completionHandler(NSURLSessionResponseAllow);
    // void (^)(NSURLSessionResponseDisposition)
}

// 2.接收到服務器的數據（可能會被調用多次）
-(void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
    NSLog(@"%s", __func__);
}

// 3.請求成功或者失敗（如果失敗，error有值）
-(void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
    NSLog(@"%s", __func__);
}

AFNetworking

• GET請求

// 第一種GET請求
AFHTTPRequestOperationManager *mgr = [AFHTTPRequestOperationManager manager];

NSDictionary *params = @{
                         @"" : @"",
                         @"" : @""
                         };

[mgr GET:@"" parameters:params
     success:^(AFHTTPRequestOperation *operation, id responseObject) {
     NSLog(@"請求成功---%@", responseObject);
 } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
     NSLog(@"請求失敗---%@", error);
}];

// 第二種GET請求
// AFHTTPSessionManager內部包裝了NSURLSession
    AFHTTPSessionManager *mgr = [AFHTTPSessionManager manager];

NSDictionary *params = @{
                         @"" : @"",
                         @"" : @""
                         };

[mgr GET:@"" parameters:params success:^(NSURLSessionDataTask *task, id responseObject) {
    NSLog(@"請求成功---%@", responseObject);
} failure:^(NSURLSessionDataTask *task, NSError *error) {
    NSLog(@"請求失敗---%@", error);
}];

• POST請求

// AFHTTPRequestOperationManager內部包裝了NSURLConnection
AFHTTPRequestOperationManager *mgr = [AFHTTPRequestOperationManager manager];

NSDictionary *params = @{
                         @"" : @"",
                         @"" : @""
                        };

[mgr POST:@"" parameters:params
     success:^(AFHTTPRequestOperation *operation, id responseObject) {
     NSLog(@"請求成功---%@", responseObject);
 } failure:^(AFHTTPRequestOperation *operation, NSError *error) {
     NSLog(@"請求失敗---%@", error);
}];