无法下载Json Array Windows Phone [英] Can't Download Json Array Windows phone
本文介绍了无法下载Json Array Windows Phone的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我可以使用以下代码在Windows 8中下载Json阵列:
I can download a Json array in Windows 8 with the following code:
aString =" http://website.com/image/image_manifest.json "；
aString = "http://website.com/image/image_manifest.json";
private async void GetJSON(string aString)
{
var client = new HttpClient();
var lResponse = await client.GetStringAsync(aString);
}
这可以100％
我正在Windows手机中尝试与此相同
I am attempting to do the same in Windows phone with this
private void GetJSON(string aNASAURL)
{
WebClient webClient = new WebClient();
webClient.DownloadStringCompleted += new DownloadStringCompletedEventHandler(webClientHandler);
webClient.DownloadStringAsync(new Uri(aString));
}
private void webClientHandler(object sender, DownloadStringCompletedEventArgs e)
{
var lResponse = e.Result;
}
这不起作用，我收到此异常:
This does not work, I receive this exception:
"System.Reflection.TargetInvocationException"类型的异常 发生在System.ni.dll中，但未在用户代码中处理
An exception of type 'System.Reflection.TargetInvocationException' occurred in System.ni.dll but was not handled in user code
进入内部异常，我看到以下内容:
Going into the inner exception I see this:
InnerException {System.Net.WebException:远程服务器返回错误:NotFound. ---> System.Net.WebException:远程服务器返回错误:NotFound.
InnerException {System.Net.WebException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound.
以下是完全例外.
HttpClient类不适用于Windows Phone.我根据网络间的建议选择了WebClient.打开其他选项. await方法似乎无效，并且WebClient必须称为Async.我认为这可能与我将字符串转换为URI有关.不幸的是，URL尚未被公开，但是这里的URL结构类似于字符串.
The HttpClient class is not available to windows phone. I chose WebClient as per the interwebs suggestion. Open to other options. The await method doesn't seem to work and WebClient must be called Async. I think that it may have something to do with my conversion of string to URI. Unfortunately the url can't yet be made public but here is a similar url structure as string.
为清楚起见而编辑……
> - e {System.Net.DownloadStringCompletedEventArgs} System.Net.DownloadStringCompletedEventArgs
+ base {System.Net.DownloadStringCompletedEventArgs} System.ComponentModel.AsyncCompletedEventArgs {System.Net.DownloadStringCompletedEventArgs}
- Result 'e.Result' threw an exception of type 'System.Reflection.TargetInvocationException' string {System.Reflection.TargetInvocationException}
- base {System.Reflection.TargetInvocationException: An exception occurred during the operation, making the result invalid. Check InnerException for exception details. ---> System.Net.WebException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound.
at System.Net.Browser.ClientHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
at System.Net.Browser.ClientHttpWebRequest.<>c__DisplayClasse.<EndGetResponse>b__d(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass1.<BeginOnUI>b__0(Object sendState)
--- End of inner exception stack trace ---
at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
at System.Net.Browser.ClientHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)
at System.Net.WebClient.DownloadBitsResponseCallback(IAsyncResult result)
--- End of inner exception stack trace ---
at System.ComponentModel.AsyncCompletedEventArgs.RaiseExceptionIfNecessary()
at System.Net.DownloadStringCompletedEventArgs.get_Result()} System.Exception {System.Reflection.TargetInvocationException}
+ Data {System.Collections.ListDictionaryInternal} System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
HelpLink null string
HResult -2146232828 int
- InnerException {System.Net.WebException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound.
at System.Net.Browser.ClientHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
at System.Net.Browser.ClientHttpWebRequest.<>c__DisplayClasse.<EndGetResponse>b__d(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass1.<BeginOnUI>b__0(Object sendState)
--- End of inner exception stack trace ---
at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
at System.Net.Browser.ClientHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)
at System.Net.WebClient.DownloadBitsResponseCallback(IAsyncResult result)} System.Exception {System.Net.WebException}
+ [System.Net.WebException] {System.Net.WebException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound.
at System.Net.Browser.ClientHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
at System.Net.Browser.ClientHttpWebRequest.<>c__DisplayClasse.<EndGetResponse>b__d(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass1.<BeginOnUI>b__0(Object sendState)
--- End of inner exception stack trace ---
at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
at System.Net.Browser.ClientHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)
at System.Net.WebClient.DownloadBitsResponseCallback(IAsyncResult result)} System.Net.WebException
+ Data {System.Collections.ListDictionaryInternal} System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
HelpLink null string
HResult -2146233079 int
- InnerException {System.Net.WebException: The remote server returned an error: NotFound.
at System.Net.Browser.ClientHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
at System.Net.Browser.ClientHttpWebRequest.<>c__DisplayClasse.<EndGetResponse>b__d(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass1.<BeginOnUI>b__0(Object sendState)} System.Exception {System.Net.WebException}
+ [System.Net.WebException] {System.Net.WebException: The remote server returned an error: NotFound.
at System.Net.Browser.ClientHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
at System.Net.Browser.ClientHttpWebRequest.<>c__DisplayClasse.<EndGetResponse>b__d(Object sendState)
at System.Net.Browser.AsyncHelper.<>c__DisplayClass1.<BeginOnUI>b__0(Object sendState)} System.Net.WebException
+ Data {System.Collections.ListDictionaryInternal} System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
HelpLink null string
HResult -2146233079 int
+ InnerException null System.Exception
Message "The remote server returned an error: NotFound." string
Source "System.Windows" string
StackTrace " at System.Net.Browser.ClientHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)\r\n at System.Net.Browser.ClientHttpWebRequest.<>c__DisplayClasse.<EndGetResponse>b__d(Object sendState)\r\n at System.Net.Browser.AsyncHelper.<>c__DisplayClass1.<BeginOnUI>b__0(Object sendState)" string
+ Static members
+ Non-Public members
Message "The remote server returned an error: NotFound." string
Source "System.Windows" string
StackTrace " at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)\r\n at System.Net.Browser.ClientHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)\r\n at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)\r\n at System.Net.WebClient.DownloadBitsResponseCallback(IAsyncResult result)" string
+ Static members
+ Non-Public members
Message "An exception occurred during the operation, making the result invalid. Check InnerException for exception details." string
Source "System" string
StackTrace " at System.ComponentModel.AsyncCompletedEventArgs.RaiseExceptionIfNecessary()\r\n at System.Net.DownloadStringCompletedEventArgs.get_Result()" string
+ Static members
+ Non-Public members
推荐答案
您可以编写类似于DownloadStringTaskAsync Jon Skeet建议的功能.
You can write a function similar to DownloadStringTaskAsync Jon Skeet suggested.
WebClient wc = new WebClient();
string result = await wc.DownloadAsync("http://www.stackoverflow.com");
public static partial class MyExtensions
{
public static Task<string> DownloadAsync(this WebClient wc, string url)
{
TaskCompletionSource<string> tcs = new TaskCompletionSource<string>();
DownloadStringCompletedEventHandler completed = null;
completed = (s, e) =>
{
try
{
tcs.SetResult(e.Result);
}
catch (Exception ex)
{
tcs.SetException(ex.InnerException ?? ex);
}
finally
{
wc.DownloadStringCompleted -= completed;
}
};
wc.Headers[HttpRequestHeader.UserAgent] = "Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.2.12) Gecko/20101026 Firefox/3.6.12";
wc.DownloadStringCompleted += completed;
wc.DownloadStringAsync(new Uri(url));
return tcs.Task;
}
}
这篇关于无法下载Json Array Windows Phone的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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