加载静态片段和FrameLayout时出错(

Question

我正在尝试使用以下layout:加载带有静态片段和LinearLayout的布局

 <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:baselineAligned="false"
    android:divider="?android:attr/dividerHorizontal"
    tools:context="com.eldad.yossi.popularmovs.MainActivity">
    <fragment
        android:id="@+id/main_fragment"
        android:name="com.eldad.yossi.popularmovs.MainActivityFragment"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="2"
        tools:layout="@android:layout/list_content" />
    <FrameLayout
        android:id="@+id/movies_detail_container"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="4" />
</LinearLayout>

但当应用程序启动时，我会收到以下错误：

11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime: FATAL EXCEPTION: ModernAsyncTask #2
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime: Process: com.eldad.yossi.popularmovs, PID: 13809
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime: java.lang.RuntimeException: An error occurred while executing doInBackground()
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.ModernAsyncTask$3.done(ModernAsyncTask.java:142)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.FutureTask.run(FutureTask.java:242)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.lang.Thread.run(Thread.java:818)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.getScheme()' on a null object reference
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.content.ContentResolver.acquireUnstableProvider(ContentResolver.java:1437)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.content.ContentResolver.query(ContentResolver.java:462)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.ContentResolverCompatJellybean.query(ContentResolverCompatJellybean.java:29)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.ContentResolverCompat$ContentResolverCompatImplJB.query(ContentResolverCompat.java:57)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.ContentResolverCompat.query(ContentResolverCompat.java:125)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.CursorLoader.loadInBackground(CursorLoader.java:59)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.CursorLoader.loadInBackground(CursorLoader.java:37)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.AsyncTaskLoader.onLoadInBackground(AsyncTaskLoader.java:296)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:54)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.AsyncTaskLoader$LoadTask.doInBackground(AsyncTaskLoader.java:42)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at android.support.v4.content.ModernAsyncTask$2.call(ModernAsyncTask.java:128)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
11-02 23:02:36.418 13809-13880/com.eldad.yossi.popularmovs E/AndroidRuntime:     at java.lang.Thread.run(Thread.java:818) 

当我使用只包含片段的布局加载它们时，相同的"活动"和片段也会起作用。

有什么想法吗？

完整的代码在GitHub的repo中-https://github.com/yossildad/PopularMovs谢谢

Answer 1

从堆栈跟踪中，我可以看到您正试图从活动com.eldad.yossi.populamovs.MainActivity.中的doInBackground（）方法中的空引用中获取URI

Answer 2

好的，我发现了错误。创建Loader时，我使用了一个未初始化的uri碎片内部。谢谢你的帮助，很抱歉给你带来麻烦。

Answer 3

您的问题不在片段声明中。根据stacktrace，查看您正在扩展的ModernASyncTask的doInBackground方法。java.lang.RuntimeException：在执行doInBackground（）时发生了一个错误——我想你可能对上下文对象有空引用。