java – Android布局预览器在添加自定义LinearLayout时会抛出错误

我定义了一个自定义viewGroup,它扩展了LinearLayout的功能：

public class TestLayout extends LinearLayout {

    public TestLayout(Context context,AttributeSet attrs) {
        super(context,attrs);

        LayoutInflater inflater = (LayoutInflater)context.getSystemService
                  (Context.LAYOUT_INFLATER_SERVICE);

        inflater.inflate(R.layout.testlayout,this,true);
    }

}

它膨胀的布局(testlayout.xml)如下所示：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" android:gravity="center">

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"/>

</LinearLayout>

最后我在main.xml中使用这个自定义组件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <my.test.namespace.TestLayout
        android:id="@+id/testLayout1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >
    </my.test.namespace.TestLayout>

</LinearLayout>

在布局编辑器中查看我的main.xml时,eclipse会抛出一个错误：
my.test.namespace.TestLayout无法实例化.

和堆栈跟踪：

android.content.res.Resources$NotFoundException: Could not resolve resource value: 0x7F030001.
    at com.android.layoutlib.bridge.android.BridgeResources.throwException(BridgeResources.java:648)
    at com.android.layoutlib.bridge.android.BridgeResources.getLayout(BridgeResources.java:270)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:318)
    at my.test.namespace.TestLayout.<init>(TestLayout.java:18)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(UnkNown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(UnkNown Source)
    at java.lang.reflect.Constructor.newInstance(UnkNown Source)
    at com.android.ide.eclipse.adt.internal.editors.layout.ProjectCallback.instantiateClass(ProjectCallback.java:397)
    at com.android.ide.eclipse.adt.internal.editors.layout.ProjectCallback.loadView(ProjectCallback.java:165)
    at com.android.layoutlib.bridge.android.BridgeInflater.loadCustomView(BridgeInflater.java:205)
    at com.android.layoutlib.bridge.android.BridgeInflater.createViewFromTag(BridgeInflater.java:133)
    at android.view.LayoutInflater.rInflate(LayoutInflater.java:618)
    at android.view.LayoutInflater.inflate(LayoutInflater.java:407)

0x7F030001指向R.java中的布局xml文件.我试着清理我的项目,但没有做任何事情.我使用LayoutInflater错了,还是这里发生了什么？