我在将 fragment 膨胀到布局时出错。 我使用的IDE是Xamarin，它是一款C#编程语言的android开发工具。

我在这个目录中的类上得到了错误

JeugdbewegingApp\JeugdbewegingApp\Presentation\MainMenu.cs

在下面的代码 fragment 中，错误是由 fragment 类名引发的。 此代码来自 NewsFeed.axml 布局文件。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <Button
        android:id="@+id/myButton"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="test" />
    <TextView
        android:text="Text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/textView1" />
    <fragment
        class="jeugdbewegingApp/jeugdbewegingApp/presentation/MainMenu"
        android:id="@+id/menu_fragment"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />
</LinearLayout>

我知道命名空间需要小写，但是您的文件和目录需要小写吗？

卡了好久没找到解决办法，我用的教程是 http://docs.xamarin.com/guides/android/platform_features/fragments/part_1_-_creating_a_fragment/

完整的错误是这样的

Android.Views.InflateException: Binary XML file line #1: Error inflating class fragment at Android.Runtime.JNIEnv.CallNonvirtualVoidMethod (intptr,intptr,intptr,Android.Runtime.JValue[]) [0x00084] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.12-series/a1e3982a/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:895 at Android.App.Activity.SetContentView (int) [0x00070] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.12-series/a1e3982a/source/monodroid/src/Mono.Android/platforms/android-19/src/generated/Android.App.Activity.cs:4252 at JeugdbewegingApp.NewsFeed.OnCreate (Android.OS.Bundle) [0x00009] in c:\Users\Jacob\Dropbox\2ICT\2de Semester\Projecten 1\Source\Jacob\JeugdbewegingApp\JeugdbewegingApp\Presentation\NewsFeed.cs:24 at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_ (intptr,intptr,intptr) [0x00011] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.12-series/a1e3982a/source/monodroid/src/Mono.Android/platforms/android-19/src/generated/Android.App.Activity.cs:2178 at at (wrapper dynamic-method) object.08e9bb04-13ac-4397-9345-6bea3473292f (intptr,intptr,intptr) at --- End of managed exception stack trace ---
at android.view.InflateException: Binary XML file line #1: Error inflating class fragment at at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:713) at at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
at at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
at at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
at at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
at at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:290) at at android.app.Activity.setContentView(Activity.java:1929) at at jeugdbewegingapp.NewsFeed.n_onCreate(Native Method) at at jeugdbewegingapp.NewsFeed.onCreate(NewsFeed.java:28) at at android.app.Activity.performCreate(Activity.java:5231) at at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) at at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) at at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) at at android.app.ActivityThread.access$800(ActivityThread.java:135)
at at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at at android.os.Handler.dispatchMessage(Handler.java:102) at at android.os.Looper.loop(Looper.java:136) at at android.app.ActivityThread.main(ActivityThread.java:5017) at at java.lang.reflect.Method.invokeNative(Native Method) at at java.lang.reflect.Method.invoke(Method.java:515) at at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) at at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at at dalvik.system.NativeStart.main(Native Method) at Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment jeugdbewegingapp/jeugdbewegingapp/presentation/MainMenu: make sure class name exists, is public, and has an empty constructor that is public at at android.app.Fragment.instantiate(Fragment.java:597) at at android.app.Fragment.instantiate(Fragment.java:561) at at android.app.Activity.onCreateView(Activity.java:4778) at at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:689) at ... 22 more at Caused by: java.lang.ClassNotFoundException: Didn't find class "jeugdbewegingapp/jeugdbewegingapp/presentation/MainMenu" on path: DexPathList[[zip file "/data/app/JeugdbewegingApp.JeugdbewegingApp-1.apk"],nativeLibraryDirectories=[/data/app-lib/JeugdbewegingApp.JeugdbewegingApp-1, /vendor/lib, /system/lib]] at at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) at at java.lang.ClassLoader.loadClass(ClassLoader.java:497) at at java.lang.ClassLoader.loadClass(ClassLoader.java:457) at at android.app.Fragment.instantiate(Fragment.java:583) at ... 25 more

如果有人能帮助我，我将不胜感激!

最佳答案

类属性应该包含类的完整命名空间，而不是路径。正如您所建议的，命名空间必须全部为小写，因为 Java 使用小写命名空间。 Xamarin 为你的自定义类生成的包装类中的命名空间将是小写的。实际的类名将保持不变，因此不需要小写。

因此，假设您的命名空间是 JeugdbewegingApp.JeugdbewegingApp.Presentation.MainMenu，您的 fragment xml 应该如下所示...

<fragment
    class="jeugdbewegingapp.jeugdbewegingapp.presentation.MainMenu"
    android:id="@+id/menu_fragment"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" />

关于c# - 错误膨胀类 fragment ，Xamarin，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22909397/