KeyboardView无法实例化

Question

我正在创建Android键盘看this教程。我看到类似的问题here和其他网站，但我没有得到解决方案。

我正在尝试将 KeyboardView 实施到我的 xml 中。但它显示了一些渲染问题和异常以下是我的Android Studio的快照

我是否需要实施任何库或某些 gradle 依赖？

例外详细信息

java.lang.UnsupportedOperationException: Unsupported Service: audio
    at com.android.layoutlib.bridge.android.BridgeContext.getSystemService(BridgeContext.java:463)
    at android.inputmethodservice.KeyboardView.<init>(KeyboardView.java:379)
    at android.inputmethodservice.KeyboardView.<init>(KeyboardView.java:283)
    at android.inputmethodservice.KeyboardView.<init>(KeyboardView.java:279)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at org.jetbrains.android.uipreview.ViewLoader.createNewInstance(ViewLoader.java:437)
    at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:154)
    at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:93)
    at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadView(LayoutlibCallbackImpl.java:190)
    at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:207)
    at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:132)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:482)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:385)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:400)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:332)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:350)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:511)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:499)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:888)
    at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:499)
    at com.android.tools.idea.rendering.RenderTask.access$600(RenderTask.java:72)
    at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:611)
    at com.android.tools.idea.rendering.RenderTask$3.call(RenderTask.java:608)
    at com.android.tools.idea.rendering.RenderService.runRenderAction(RenderService.java:363)
    at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:608)
    at com.android.tools.idea.rendering.RenderTask.render(RenderTask.java:630)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.doRender(AndroidLayoutPreviewToolWindowManager.java:643)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.access$1700(AndroidLayoutPreviewToolWindowManager.java:80)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7$1.run(AndroidLayoutPreviewToolWindowManager.java:585)
    at com.intellij.openapi.progress.impl.CoreProgressManager$2.run(CoreProgressManager.java:152)
    at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:452)
    at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:402)
    at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54)
    at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:137)
    at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7.run(AndroidLayoutPreviewToolWindowManager.java:580)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:320)
    at com.intellij.util.ui.update.MergingUpdateQueue.execute(MergingUpdateQueue.java:310)
    at com.intellij.util.ui.update.MergingUpdateQueue$2.run(MergingUpdateQueue.java:254)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:269)
    at com.intellij.util.ui.update.MergingUpdateQueue.flush(MergingUpdateQueue.java:227)
    at com.intellij.util.ui.update.MergingUpdateQueue.run(MergingUpdateQueue.java:217)
    at com.intellij.util.concurrency.QueueProcessor.runSafely(QueueProcessor.java:238)
    at com.intellij.util.Alarm$Request$1.run(Alarm.java:351)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

这是我的 Manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="corp.trees.com.kbtsimplekeyboard" >

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <service android:name=".SimpleIME"
            android:label="@string/simple_ime"
            android:permission="android.permission.BIND_INPUT_METHOD"
            >
            <meta-data android:name="android.view.im" android:resource="@xml/method"/>
            <intent-filter>
                <action android:name="android.view.InputMethod" />
            </intent-filter>
        </service>            
    </application>    
</manifest>