错误:<item>标记需要一个'drawable'属性或定义drawable的子标记

Question

我item_bg_selector.xml在drawable文件夹中创建了一个状态列表选择器文件,如下所示:

<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>

然后我定义一个样式元素

<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>

然后我尝试创建ImageButton这样的:

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

Eclipse不断在Event Details窗口中给出以下错误:

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

异常跟踪如下:

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)

现在,问题在于错误在哪里？drawables存在于文件夹中.tag具有drawable属性.我已经交叉检查了近15次,但我仍然无法找到问题.我相信这是一个非常简单的问题(如果有的话).任何解决这个问题的工作也值得赞赏.

另外:第16行item_bg_selector.xml对应于我发布的文件中从顶部开始的第三行.那是

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

Answer 1

错误与xml的格式有关,你设置的类似

android:background="@drawable/item_bg_selector"

错误告诉你的是它应该是这样的

android:drawable="@drawable/item_bg_selector"

Answer 2

我有同样的错误,并切换属性的顺序(因为它是在暗示这个回答这个其他问题)有第一个可绘制解决了这个问题.

在你的情况下将切换:

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

至:

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

Answer 3

最后,我知道它只是ADT的一个问题,它实际上在设备上运行良好.这对应于问题21046.

Answer 4

对于不同的问题,我遇到过相同的异常.

我试图使用颜色选择器为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>

将选择器移动到drawable文件夹并更改android:color以android:drawable解决问题.

此外,布局中的背景定义需要更改为 android:background="@drawable/tab_background_selector"

这是最终的选择器:

<!-- /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>

Answer 5

与此答案类似，我需要制作drawable该color资源的版本。

解决方案

1. 创建一个新的可绘制文件，而不是修改现有的颜色状态列表文件

   new_drawable_file.xml

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

2. 然后我更新了有问题的用法@color/old_color_state_listto @drawable/new_drawable_file。

背景

• 在我的styles.xml，我已经用?android:activatedBackgroundIndicator我的@color/old_color_state_list

  <item name="android:activatedBackgroundIndicator">@color/old_color_state_list</item>
  

• 但文档?android:activatedBackgroundIndicator说它应该是一种drawable资源，而不是color：

  Drawable 用作激活项目的背景。

• 所以，我更新了我的以用我的可绘制对象styles.xml覆盖。 ?android:activatedBackgroundIndicator@drawable/new_drawable_file

  <item name="android:activatedBackgroundIndicator">@drawable/new_drawable_file</item>