從Windows Phone 8中的URL檢索JSON字符串

Question

我正在嘗試從Windows Phone 8應用程序中的Url獲取一個Json字符串（該頁面需要身份驗證，我認為這是我的代碼失敗的地方），我正在使用以下代碼：

    public WebClient client = new WebClient();
    public string result;

    public void DoStuff()
    {
        string username = "username";
        string password = "password";
        string url = "myurl";
        client.Credentials = new NetworkCredential(username, password);
        client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(webClient_DownloadStringCompleted);
        client.DownloadStringAsync(new Uri(url));
    }
    void webClient_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
    {
        result = e.Result;
    }

但是，運行該應用程序時，在e.result上出現了System.Reflection.TargetInvocationException

進入InnerException我看到了：

[System.Net.WebException] {System.Net.WebException：WebClient請求期間發生異常。 ---> System.Net.ProtocolViolationException：使用此方法的請求不能具有請求主體。 在System.Net.Browser.AsyncHelper.BeginOnUI（SendOrPostCallback beginMethod，Object state）在System.Net.Browser.ClientHttpWebRequest.EndGetResponse（IAsyncResult asyncResult）在System.Net.WebClient.GetWebResponse（WebRequest request，IAsyncResult result） .WebClient.DownloadBitsResponseCallback（IAsyncResult result）---內部異常堆棧跟蹤的結尾---} System.Net.WebException

我嘗試使用HttpClient，但遇到了同樣的問題。 我想知道是否有人知道如何解決這個問題。

謝謝！

更新：我嘗試使用IE導航到手機上的頁面，然后IE Mobile說：“地址不受支持，IE Mobile不支持這種類型的地址，因此無法顯示此頁面”。 這就是為什么應用程序也崩潰的原因？

Answer 1

GET方法（具有/不具有憑據）

private string username = "user";
private string password = "passkey";
private string myUrl = "http://some_url.com/id?=20";
private WebClient client = new WebClient();

private void retrieveJson()
{
        client.Credentials = new NetworkCredential(username, password);
        client.Encoding = Encoding.UTF8;
        client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(wc_DownloadStringCompleted);
        client.DownloadStringAsync(new Uri(myUrl), UriKind.Relative);
}
//WebClient String (json content) Download
private void wc_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
{
        // You will get you Json Data here..
        var myJSONData = e.Result;
        JObject JsonData = JObject.Parse(myJSONData);
        //Do something with json 
        //Ex: JsonData["Array1"][5]
}

POST方法（具有/不具有憑據）

private string username = "user";
private string password = "passkey";
private string myUrl = "http://some_url.com/id?=20";
private WebClient client = new WebClient();
private string parameters = "{\"I_NAME\":\"0000"\"}"; //Example

private void postMethod()
{
        client.Credentials = new NetworkCredential(username, password);
        client.Encoding = Encoding.UTF8;
        client.Headers["Content-Length"] = parameters.Length.ToString();
        client.UploadStringCompleted += new UploadStringCompletedEventHandler(client_UploadStringCompleted);

        client.UploadStringAsync(new Uri(myUrl), "POST", parameters);
}

private void client_UploadStringCompleted(object sender, UploadStringCompletedEventArgs e)
{
        if (e.Error == null)
        {
            var myJSONData = e.Result;
            JObject JsonData = JObject.Parse(myJSONData);
        }
}