AFNetworking 關(guān)于JSON text did not start with array or object and option to allow fragments not set 錯誤

1、AFNetworking 報(bào)錯Request failed: unacceptable content-type: text/html"
  解決：
 AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
 manager.responseSerializer = [AFHTTPResponseSerializer serializer];
 //注意不是json
manager.responseSerializer.acceptableContentTypes = [NSSet setWithObject:@"application/json"];
  manager.responseSerializer.acceptableContentTypes = [NSSet setWithObject:@"text/html"];

2、AFNetworking 報(bào)錯：JSON text did not start with array or object and option to allow fragments not set 
解決：
在AFNetworking中 上述代碼將會 輸出

Error Domain=NSCocoaErrorDomain Code=3840 "The operation couldn’t be completed. (Cocoa error 3840.)" (JSON text did not start with array or object and option to allow fragments not set.) UserInfo=0x8ea19a0 {NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.}
這是因?yàn)?AFNetworking默認(rèn)把響應(yīng)結(jié)果當(dāng)成json來處理,(默認(rèn)manager.responseSerializer = [AFJSONResponseSerializer serializer]) ,很顯然,我們請求的百度首頁 返回的并不是一個json文本,而是一個html網(wǎng)頁,但是AFNetworking并不知道,它堅(jiān)信請求的結(jié)果就是一個json文本!然后固執(zhí)地以json的形式去解析,顯然沒辦法把一個網(wǎng)頁解析成一個字典或者數(shù)組,所以產(chǎn)生了上述錯誤.

然而,我們期望它能夠正確地處理這個情形,而不是提示一個錯誤. 
這時候 你必須告訴AFNetworking:別把這個網(wǎng)頁當(dāng)json來處理! 
只需要在發(fā)送請求前加入:manager.responseSerializer = [AFHTTPResponseSerializer serializer]

代碼變成:

    AFHTTPSessionManager *manager =[AFHTTPSessionManager manager];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    [manager GET:@"http://www.baidu.com" parameters:nil success:^(NSURLSessionDataTask *task, id responseObject) {
        NSString *result = [[NSString alloc]initWithData:responseObject encoding:NSUTF8StringEncoding];
        NSLog(@"%@",result);
    } failure:^(NSURLSessionDataTask *task, NSError *error) {
        NSLog(@"%@",error);
    }];