Error : tag requires a 'drawable' a

问题:

I created a state-list selector file item_bg_selector.xml in the drawable folder like this :

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_selected="true" 
      android:drawable="@drawable/item_background_selected" />
  <item android:state_focused="true" 
      android:drawable="@drawable/item_background_selected" />
  <item android:state_pressed="true" 
      android:drawable="@drawable/item_background_selected" />
  <item android:drawable="@android:color/transparent"/>
</selector>

Then i define a style element

<style name="Item">
    <item name="android:layout_width">wrap_content</item>
    <item name="android:layout_height">wrap_content</item>
    <item name="android:background">@drawable/item_bg_selector</item>
</style>

Then I try to create an ImageButton like this :

    <ImageButton style="@style/Item"
        android:id="@id/btn_home"
    android:src="@drawable/home_button" />

Eclipse keeps giving me the following error in the Event Details window :

Failed to parse file /path/to/projectdir/res/drawable/item_bg_selector.xml

The exception trace is given below :

org.xmlpull.v1.XmlPullParserException: Binary XML file line #16: <item> tag requires a 'drawable' attribute or child tag defining a drawable
    at android.graphics.drawable.StateListDrawable.inflate(StateListDrawable.java:167)
    at android.graphics.drawable.Drawable.createFromXmlInner(Drawable.java:787)
    at android.graphics.drawable.Drawable.createFromXml(Drawable.java:728)
    at com.android.layoutlib.bridge.impl.ResourceHelper.getDrawable(ResourceHelper.java:208)
    at com.android.layoutlib.bridge.android.BridgeTypedArray.getDrawable(BridgeTypedArray.java:731)
    at android.view.View.<init>(View.java:1885)
    at android.widget.ImageView.<init>(ImageView.java:112)
    at android.widget.ImageButton.<init>(ImageButton.java:85)
    at android.widget.ImageButton.<init>(ImageButton.java:81)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at android.view.LayoutInflater.createView(LayoutInflater.java:500)
    at com.android.layoutlib.bridge.android.BridgeInflater.onCreateView(BridgeInflater.java:84)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:563)
    at com.android.layoutlib.bridge.android.BridgeInflater.createViewFromTag(BridgeInflater.java:129)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:618)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:621)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:407)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:296)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:279)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:318)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:325)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.RenderService.createRenderSession(RenderService.java:372)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.renderWithBridge(GraphicalEditorPart.java:1317)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.recomputeLayout(GraphicalEditorPart.java:1071)
    at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.activated(GraphicalEditorPart.java:897)
    at com.android.ide.eclipse.adt.internal.editors.layout.LayoutEditor.pageChange(LayoutEditor.java:384)
    at org.eclipse.ui.part.MultiPageEditorPart$2.widgetSelected(MultiPageEditorPart.java:290)
    at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:234)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Display.sendEvent(Display.java:3783)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1375)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1398)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1383)
    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1195)
    at org.eclipse.swt.custom.CTabFolder.setSelection(CTabFolder.java:2743)
    at org.eclipse.swt.custom.CTabFolder.onMouse(CTabFolder.java:1429)
    at org.eclipse.swt.custom.CTabFolder$1.handleEvent(CTabFolder.java:257)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Display.sendEvent(Display.java:3783)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1375)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1398)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1383)
    at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1195)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3629)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3284)
    at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438)
    at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:369)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:620)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1408)

Now, The question is where is the error? the drawables exist in the folder. tag has a drawable attribute. I have cross checked this close to 15 times and still I have not been able to find the problem. I believe it is a very simple problem(if any). Any work around to get over with this is also appreciated.

Addition : Also, line 16 in item_bg_selector.xml corresponds to the third line from the top in the file I have posted. that is

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_selected="true" 
line16 ----> android:drawable="@drawable/item_background_selected" />

回答1:

The error has to do with the format of your xml, you are setting something like

android:background="@drawable/item_bg_selector"

What the error is telling you is that it should be like this

android:drawable="@drawable/item_bg_selector"

回答2:

I had the same error and switching the order of the attributes (as it was suggested in the this answer to this other question) to have the drawable the first one solved the problem.

In your case would be switching:

  <item android:state_selected="true" 
   android:drawable="@drawable/item_background_selected" />

to:

  <item android:drawable="@drawable/item_background_selected"
   android:state_selected="true" />

回答3:

Finally, I got to know that its a problem with just ADT and it actually runs fine on the device. This corresponds to issue 21046.

回答4:

I've experienced the same Exception for a different problem.

I was trying to use a color selector for the View's android:background:

<RadioButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@color/tab_background_selector" />

<!-- /res/color/tab_background_selector.xml -->
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@color/white" android:state_checked="true" />
    <item android:color="@color/light_blue" />
</selector>

Moving the selector to the drawable folder and changing android:color to android:drawable solved the problem.

Also, the background definition in the Layout needs to be changed to android:background="@drawable/tab_background_selector"

Here is the final selector:

<!-- /res/drawable/tab_background_selector.xml -->
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@color/white" android:state_checked="true" />
    <item android:drawable="@color/light_blue" />
</selector>

回答5:

I also encountered the same issue.

I just restarted eclipse with -clean, and the did a project -> Clean on the project in question and the errors have gone away.

回答6:

Restarting Eclipse and cleaning the project worked for me.

回答7:

The drawable inside the file (a png) was corrupted. I just saved again the file and it worked.

回答8:

I got it to work by copying the image right into the file system (Finder on Mac) rather than through Android Studio.

回答9:

I had the problem because when renaming the selector for pre-lollipop devices, I forgot to rename the ripple with th e same name also in the drawable-v21 folder.

回答10:

The same error occurs on the activity_main.xml file if there is an extra LinearLayout in the Activity. Removing this solves the issue.

Cleaning and other things do not help.