Question

我试图预览我的MainActivity XML文件，但我收到此错误：

java.lang.ClassNotFoundException：android.support.v4.widget.DrawerLayoutImpl

我的主片段和导航抽屉片段工作得很好。

在这些论坛上搜索并尝试了一些无济于事的事情。我知道这应该是图书馆和我的gradle构建的一个问题，但我不确定我做错了什么：

apply plugin: 'com.android.application'

android {
compileSdkVersion 21
buildToolsVersion '21.0.0'

defaultConfig {
    applicationId "com.example.example"
    minSdkVersion 17
    targetSdkVersion 21
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        runProguard false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}    
}

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:support-v4:21.0.0'
compile 'com.parse.bolts:bolts-android:1.1.2'
compile 'com.android.support:support-v13:21.0.0'
compile fileTree(dir: 'libs', include: 'Parse-*.jar')
compile project(':facebook')
}

自从我使用导航抽屉以来，android工作室自动添加了

v4。 v13我自己（通过转到项目结构 - >依赖关系并在那里添加它）认为它会有所帮助。我将两个.jar文件复制到我的libs文件夹中，认为这也有帮助。清理过的项目/同步的gradle做了所有这些，不知道还能做什么。

以防万一，这是Android Studio为我创建的activity_main.xml

<!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<!-- As the main content view, the view below consumes the entire
     space available using match_parent in both dimensions. -->
<FrameLayout
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<!-- android:layout_gravity="start" tells DrawerLayout to treat
     this as a sliding drawer on the left side for left-to-right
     languages and on the right side for right-to-left languages.
     If you're not building against API 17 or higher, use
     android:layout_gravity="left" instead. -->
<!-- The drawer is given a fixed width in dp and extends the full height of
     the container. -->
<fragment android:id="@+id/navigation_drawer"
    android:layout_width="@dimen/navigation_drawer_width"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:name="com.example.example.NavigationDrawerFragment"
    tools:layout="@layout/fragment_navigation_drawer" />

</android.support.v4.widget.DrawerLayout>

整个堆栈痕迹

java.lang.ClassNotFoundException: android.support.v4.widget.DrawerLayoutImpl
at com.android.tools.idea.rendering.RenderClassLoader.findClass(RenderClassLoader.java:53)
at org.jetbrains.android.uipreview.ProjectClassLoader.findClass(ProjectClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.)
at java.lang.ClassLoader.loadClass(ClassLoader.)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.)
at java.lang.ClassLoader.defineClass(ClassLoader.)
at java.lang.ClassLoader.defineClass(ClassLoader.)
at com.android.tools.idea.rendering.RenderClassLoader.loadClassFromJar(RenderClassLoader.java:93)
at org.jetbrains.android.uipreview.ProjectClassLoader.loadClassFromModuleOrDependency(ProjectClassLoader.)
at org.jetbrains.android.uipreview.ProjectClassLoader.load(ProjectClassLoader.java:89)
at com.android.tools.idea.rendering.RenderClassLoader.findClass(RenderClassLoader.java:56)
at org.jetbrains.android.uipreview.ProjectClassLoader.findClass(ProjectClassLoader.java:56)
at java.lang.ClassLoader.loadClass(ClassLoader.)
at java.lang.ClassLoader.loadClass(ClassLoader.)
at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.)
at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:96)
at com.android.tools.idea.rendering.LayoutlibCallback.loadView(LayoutlibCallback.)
at android.view.BridgeInflater.loadCustomView(BridgeInflater.)
at android.view.BridgeInflater.createViewFromTag(BridgeInflater.)
at android.view.LayoutInflater.inflate(LayoutInflater.)
at android.view.LayoutInflater.inflate(LayoutInflater.)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.)
at com.android.layoutlib.bridge.Bridge.createSession(Bridge.)
at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.)
at com.android.tools.idea.rendering.RenderService$3.compute(RenderService.)
at com.android.tools.idea.rendering.RenderService$3.compute(RenderService.)
at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.)
at com.android.tools.idea.rendering.RenderService.createRenderSession(RenderService.)
at com.android.tools.idea.rendering.RenderService.render(RenderService.)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.doRender(AndroidLayoutPreviewToolWindowManager.)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.access$1900(AndroidLayoutPreviewToolWindowManager.java:80)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7$1.run(AndroidLayoutPreviewToolWindowManager.)
at com.intellij.openapi.progress.impl.ProgressManagerImpl$2.run(ProgressManagerImpl.)
at com.intellij.openapi.progress.ProgressManager.executeProcessUnderProgress(ProgressManager.)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.runProcess(ProgressManagerImpl.)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7.run(AndroidLayoutPreviewToolWindowManager.)
at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.)
at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.)
at com.intellij.util.ui.update.MergingUpdateQueue$2.run(MergingUpdateQueue.)
at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.)
at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.)
at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.)
at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.)
at com.intellij.util.Alarm$Request$1.run(Alarm.)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.)
at java.util.concurrent.FutureTask.run(FutureTask.)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.)
at java.lang.Thread.run(Thread.)

Answer 1

重新安装Android Studio（v.2.2.2）（Ubuntu系统）后，我遇到了插件问题（File-＆gt; Settings-＆gt; Plugins），如：

Problems found loading Plugins in Android Studio

所以我关闭了插件并忘了打开它们。之后发生了许多构建错误。其中之一：

android.support.v4.widget.DrawerLayout无法实例化

当我重新安装Android Studio并再次打开所有插件时，所有错误都消失了。

android.support.v4.widget.DrawerLayout无法实例化

1 个答案: