C＃：ModernHttpClient，您在应用程序中引用了Portable版本 - 您需要引用平台（iOS / Android）版本

Question

我正在使用ModernHttpClient库，我试图从httpClient的响应中获取Cookie

public static async Task<String> loginUser()
{
    var values = new List<KeyValuePair<string, string>>
    {
        new KeyValuePair<string, string>("username", "*****"),
        new KeyValuePair<string, string>("password", "*****"),
    };
    NativeCookieHandler cookieHandler = new NativeCookieHandler();
    NativeMessageHandler messageHandler = new NativeMessageHandler(false, false, cookieHandler);
    var httpClient = new HttpClient(messageHandler);

    var response = await httpClient.PostAsync(RestApiPaths.LOGIN, new FormUrlEncodedContent(values));

    response.EnsureSuccessStatusCode();
    String resultString = await response.Content.ReadAsStringAsync();
    System.Diagnostics.Debug.WriteLine("resultString: " + resultString);
    IEnumerable<Cookie> responseCookies = cookieHandler.Cookies;
    Cookie mCookie = responseCookies.FirstOrDefault();
    RestApiPaths.mCookie = mCookie;
    return resultString;

}

但是以下行给出错误：

IEnumerable<Cookie> responseCookies = cookieHandler.Cookies;

错误：

MonoDroid] UNHANDLED EXCEPTION:
[MonoDroid] System.Exception: You're referencing the Portable version in your App - you need to reference the platform (iOS/Android) version
[MonoDroid]   at Gogch.MyClass+<loginUser>c__async0.MoveNext () <0x9e0d9e08 + 0x004b8> in <filename unknown>:0 
[MonoDroid] --- End of stack trace from previous location where exception was thrown ---
[MonoDroid]   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () <0x9d3a3670 + 0x00024> in <filename unknown>:0 
[MonoDroid]   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) <0x9d3a2ff8 + 0x000bb> in <filename unknown>:0 
[MonoDroid]   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) <0x9d3a2dd0 + 0x0008b> in <filename unknown>:0 
[MonoDroid]   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) <0x9d6ecaa8 + 0x0003f> in <filename unknown>:0 
[MonoDroid]   at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () <0xa1f0fa18 + 0x0001b> in <filename unknown>:0 
[MonoDroid]   at Gogch.Droid.MainActivity+<button_OnClick>c__async0.MoveNext () <0xaf58c608 + 0x00137> in <filename unknown>:0 
[MonoDroid] --- End of stack trace from previous location where exception was thrown ---
[MonoDroid]   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () <0x9d3a3670 + 0x00024> in <filename unknown>:0 
[MonoDroid]   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>m__0 (System.Object state) <0x9d3a4488 + 0x0003f> in <filename unknown>:0 
[MonoDroid]   at Android.App.SyncContext+<Post>c__AnonStorey0.<>m__0 () <0xa1f0f968 + 0x00027> in <filename unknown>:0 
[MonoDroid]   at Java.Lang.Thread+RunnableImplementor.Run () <0xa1f0f7b8 + 0x0003f> in <filename unknown>:0 
[MonoDroid]   at Java.Lang.IRunnableInvoker.n_Run (IntPtr jnienv, IntPtr native__this) <0xa1f0f710 + 0x0003f> in <filename unknown>:0 
[MonoDroid]   at (wrapper dynamic-method) System.Object:ba036dc5-deef-4850-b986-e1e85c84e6de (intptr,intptr)
[art] JNI RegisterNativeMethods: attempt to register 0 native methods for android.runtime.JavaProxyThrowable
[AndroidRuntime] Shutting down VM
[AndroidRuntime] FATAL EXCEPTION: main
[AndroidRuntime] Process: com.cinch.gogch, PID: 18910
[AndroidRuntime] java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
[AndroidRuntime]    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
[AndroidRuntime] Caused by: java.lang.reflect.InvocationTargetException
[AndroidRuntime]    at java.lang.reflect.Method.invoke(Native Method)
[AndroidRuntime]    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
[AndroidRuntime]    ... 1 more
[AndroidRuntime] Caused by: android.runtime.JavaProxyThrowable: System.Exception: You're referencing the Portable version in your App - you need to reference the platform (iOS/Android) version
[AndroidRuntime]   at Gogch.MyClass+<loginUser>c__async0.MoveNext () <0x9e0d9e08 + 0x004b8> in <filename unknown>:0 
[AndroidRuntime] --- End of stack trace from previous location where exception was thrown ---
[AndroidRuntime]   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () <0x9d3a3670 + 0x00024> in <filename unknown>:0 
[AndroidRuntime]   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) <0x9d3a2ff8 + 0x000bb> in <filename unknown>:0 
[AndroidRuntime]   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) <0x9d3a2dd0 + 0x0008b> in <filename unknown>:0 
[AndroidRuntime]   at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) <0x9d6ecaa8 + 0x0003f> in <filename unknown>:0 
[AndroidRuntime]   at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () <0xa1f0fa18 + 0x0001b> in <filename unknown>:0 
[AndroidRuntime]   at Gogch.Droid.MainActivity+<button_OnClick>c__async0.MoveNext () <0xaf58c608 + 0x00137> in <filename unknown>:0 
[AndroidRuntime] --- End of stack trace from previous location where exception was thrown ---
[AndroidRuntime]   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () <0x9d3a3670 + 0x00024> in <filename unknown>:0 
[AndroidRuntime]   at System.Runtime.CompilerServices.AsyncMethodBuilderCore.<ThrowAsync>m__0 (System.Object state) <0x9d3a4488 + 0x0003f> in <filename unknown>:0 
[AndroidRuntime]   at Android.App.SyncContext+<Post>c__AnonStorey0.<>m__0 () <0xa1f0f968 + 0x00027> in <filename unknown>:0 
[AndroidRuntime]   at Java.Lang.Thread+RunnableImplementor.Run () <0xa1f0f7b8 + 0x0003f> in <filename unknown>:0 
[AndroidRuntime]   at Java.Lang.IRunnableInvoker.n_Run (IntPtr jnienv, IntPtr native__this) <0xa1f0f710 + 0x0003f> in <filename unknown>:0 
[AndroidRuntime]   at (wrapper dynamic-method) System.Object:ba036dc5-deef-4850-b986-e1e85c84e6de (intptr,intptr)
[AndroidRuntime]    at mono.java.lang.RunnableImplementor.n_run(Native Method)
[AndroidRuntime]    at mono.java.lang.RunnableImplementor.run(RunnableImplementor.java:30)
[AndroidRuntime]    at android.os.Handler.handleCallback(Handler.java:746)
[AndroidRuntime]    at android.os.Handler.dispatchMessage(Handler.java:95)
[AndroidRuntime]    at android.os.Looper.loop(Looper.java:148)
[AndroidRuntime]    at android.app.ActivityThread.main(ActivityThread.java:5443)
[AndroidRuntime]    ... 3 more

我把这个代码放在PCL中。 为什么我收到此错误？ 如何正确获取cookie？

编辑：

现在我在我的pcl和ios项目中都使用了modernhttpclient库来使其工作。 如果我从ios项目中删除它。 我犯了同样的错误。

Answer 1

当您添加对解决方案的引用时，您是否添加了对PCL项目以及iOS和Android项目的引用？

它是相同的Nuget包，但是android包添加了一个引用

〜\\包\\ modernhttpclient.2.4.2 \\ LIB \\ MonoAndroid

iOS获取引用

〜\\包\\ modernhttpclient.2.4.2 \\ LIB \\ Xamarin.iOS10

我假设这是在Visual Studio中？ 也许只需卸载软件包并重新安装（并在解决方案级别安装）。

Answer 2

确保您的项目具有对程序集的正确引用：

• Android：在MonoAndroid文件夹中
• iOS：在Xamarin.iOS10文件夹（或MonoTouch文件夹）中
• PCL：在Portable-Net45+WinRT45+WP8+WPA81文件夹中

如果这没有帮助，我建议停止使用ModernHttpClient ，因为下一个：

1. Xamarin.iOS 提供的ModernHttpClient的功能开箱（有点有限虽然）的。
2. 实际上， ModernHttpClient.NativeMessageHandler对cookieHandler参数没有任何cookieHandler 。 您可以在源代码（ Android ， iOS ）中查看它。 您可以原生地处理cookie而不是使用ModernHttpClient实现，请参阅示例的源代码（ Android ， iOS ）。

Answer 3

如Eugene和HeisenBerg所解释的更多澄清。 你被“ 诱饵和开关 ”困住了

Answer 4

对于未来的googlers：当您将某些NuGet引用（例如modernhttpclient-updated ） modernhttpclient-updated为针对Xamarin.Android 8.1 （仅作为示例）的版本时，可能会发生这种情况，而您的应用程序针对Xamarin.Android 6.0 ：在这种情况下您的Xamarin.Android项目不会引用特定于平台的代码，而只是共享代码。

注意NuGet警告！