android:elevation标记在android布局文件中引发了问题

我正在尝试创建一个FAB，当我添加

android:elevation=“2dp”

时，我得到一个异常！我正在使用的代码，我以前使用过，到现在为止我没有问题，我找不到问题。这可能是一个android studio错误，我不知道，但任何帮助将不胜感激

<ImageButton
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:id="@+id/imageButton"
     android:layout_alignParentBottom="true"
     android:layout_alignParentEnd="true"
     android:src="@drawable/ic_arrow_forward_black_18dp"
     android:background="@drawable/ripple_oval"
     android:stateListAnimator="@anim/animation"
     android:elevation="2dp"
     android:onClick="signIn"
     android:tint="@android:color/white"/>

这里是错误

java.lang.IllegalArgumentException: Width (2) and height (0) cannot be <= 0
at java.awt.image.DirectColorModel.createCompatibleWritableRaster(DirectColorModel.java:999)
at java.awt.image.BufferedImage.<init>(BufferedImage.java:326)
at android.graphics.LinearGradient_Delegate$LinearGradientPaint$LinearGradientPaintContext.getRaster(LinearGradient_Delegate.java:175)
at apple.awt.OSXSurfaceData.setupPaint(OSXSurfaceData.java:752)
at apple.awt.OSXSurfaceData.setupGraphicsState(OSXSurfaceData.java:1038)
at apple.awt.OSXSurfaceData.setupGraphicsState(OSXSurfaceData.java:1004)
at apple.awt.OSXSurfaceData.doRect(OSXSurfaceData.java:1239)
at apple.awt.CRenderer.fillRect(CRenderer.java:157)
at apple.awt.CRenderer.fillRect(CRenderer.java:145)
at sun.java2d.pipe.ValidatePipe.fillRect(ValidatePipe.java:58)
at sun.java2d.SunGraphics2D.fillRect(SunGraphics2D.java:2505)
at android.graphics.Canvas_Delegate$4.draw(Canvas_Delegate.java:582)
at com.android.layoutlib.bridge.impl.GcSnapshot.drawOnGraphics(GcSnapshot.java:654)
at com.android.layoutlib.bridge.impl.GcSnapshot.drawInLayer(GcSnapshot.java:614)
at com.android.layoutlib.bridge.impl.GcSnapshot.draw(GcSnapshot.java:582)
at android.graphics.Canvas_Delegate.draw(Canvas_Delegate.java:937)
at android.graphics.Canvas_Delegate.native_drawRect(Canvas_Delegate.java:573)
at android.graphics.Canvas.native_drawRect(Canvas.java)
at android.graphics.Canvas.drawRect(Canvas.java:1119)
at android.view.RectShadowPainter.sideShadow(RectShadowPainter.java:131)
at android.view.RectShadowPainter.paintShadow(RectShadowPainter.java:79)
at android.view.ViewGroup_Delegate.drawShadow(ViewGroup_Delegate.java:72)
at android.view.ViewGroup_Delegate.drawChild(ViewGroup_Delegate.java:61)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.draw(View.java:15138)
at android.view.ViewGroup.drawChild_Original(ViewGroup.java:3405)
at android.view.ViewGroup_Delegate.drawChild(ViewGroup_Delegate.java:65)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.draw(View.java:15138)
at android.view.ViewGroup.drawChild_Original(ViewGroup.java:3405)
at android.view.ViewGroup_Delegate.drawChild(ViewGroup_Delegate.java:65)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.draw(View.java:15138)
at android.view.ViewGroup.drawChild_Original(ViewGroup.java:3405)
at android.view.ViewGroup_Delegate.drawChild(ViewGroup_Delegate.java:65)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.draw(View.java:15234)
at android.view.View.draw(View.java:15140)
at android.view.ViewGroup.drawChild_Original(ViewGroup.java:3405)
at android.view.ViewGroup_Delegate.drawChild(ViewGroup_Delegate.java:65)
at android.view.ViewGroup.drawChild(ViewGroup.java:3405)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3198)
at android.view.View.draw(View.java:15234)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.render(RenderSessionImpl.java:601)
at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:323)
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:645)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager.access$1700(AndroidLayoutPreviewToolWindowManager.java:80)
at org.jetbrains.android.uipreview.AndroidLayoutPreviewToolWindowManager$7$1.run(AndroidLayoutPreviewToolWindowManager.java:587)
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:582)
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:439)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at java.lang.Thread.run(Thread.java:695)

---

java.lang.IllegalArgumentException:Width（2）和height（0）不能是我也有同样的问题。
通过将API级别从22降低到21，渲染停止抛出错误，我解决了这个问题

但是，即使我的Android Studio显示渲染错误，当我在模拟器和Android设备上运行它时，它仍然显示良好。
您的目标API级别是哪个？@siris\u cac我的目标API级别21（棒棒糖）
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
   <item android:state_pressed="true">
     <objectAnimator
        android:propertyName="translationZ"
        android:duration="@android:integer/config_shortAnimTime"
        android:valueTo="1dp"
        android:valueFrom="8dp"
        android:valueType="floatType"/>
   </item>
   <item>
     <objectAnimator
        android:propertyName="translationZ"
        android:duration="@android:integer/config_shortAnimTime"
        android:valueFrom="8dp"
        android:valueTo="1dp"
        android:valueType="floatType"/>
   </item>
</selector>

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="@color/accentDark">
       <item>
          <shape android:shape="oval">
          <solid android:color ="@color/accentDark"/>
          </shape>
       </item>
</ripple>