Android:在自定义 View 上膨胀异常

Question

我有一个扩展 LinearLayout 的自定义 View ，具有以下构造函数:

public class CustomView extends LinearLayout {

public CustomView(Context context) {
    this(context, null);
}

public CustomView(Context context, AttributeSet attrs) {
    this(context, attrs, R.attr.customViewStyle);
}

public CustomView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    /* set custom attributes with TypedArray */
}

    /* other methods */
}

在我的/res/values/attrs.xml 中:

<attr name="customViewStyle" format="reference" />

<declare-styleable name="CustomeView">
    <attr name="value" format="integer" />
    <attr name="android:imeOptions" />
    <attr name="android:imeActionId" />
    <attr name="android:imeActionLabel" />
</declare-styleable>

在我的/res/values/styles.xml 中:

<style name="AppTheme" parent="@android:style/Theme.Black">
    <item name="android:windowBackground">@drawable/bg_dark_fiber</item>
    <item name="customViewStyle">@style/CustomViewStyle</item>
</style>

<style name="CustomViewStyle">
    <item name="android:clickable">true</item>
    <item name="android:focusable">true</item>
    <item name="android:focusableInTouchMode">true</item>
</style>

AppTheme 设置为整个应用的主题。期望的结果是我的自定义 View 在默认情况下是可聚焦和可点击的，而无需在我的布局文件中添加这些属性(而常规的 LinearLayout 则不是)。当我运行该应用程序时，它崩溃并显示以下堆栈跟踪:

05-17 14:58:53.010: E/ActivityThread(26767): Failed to inflate
05-17 14:58:53.010: E/ActivityThread(26767): android.view.InflateException: Binary XML file line #8: Error inflating class com.example.customviews.CustomView
05-17 14:58:53.010: E/ActivityThread(26767):    at android.view.LayoutInflater.createView(LayoutInflater.java:518)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:570)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-17 14:58:53.010: E/ActivityThread(26767):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:212)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.app.Activity.setContentView(Activity.java:1657)
05-17 14:58:53.010: E/ActivityThread(26767):    at com.example.pincode.PinCodeActivity.onCreate(PinCodeActivity.java:26)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.app.ActivityThread.access$1500(ActivityThread.java:123)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.os.Looper.loop(Looper.java:130)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.app.ActivityThread.main(ActivityThread.java:3835)
05-17 14:58:53.010: E/ActivityThread(26767):    at java.lang.reflect.Method.invokeNative(Native Method)
05-17 14:58:53.010: E/ActivityThread(26767):    at java.lang.reflect.Method.invoke(Method.java:507)
05-17 14:58:53.010: E/ActivityThread(26767):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847)
05-17 14:58:53.010: E/ActivityThread(26767):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605)
05-17 14:58:53.010: E/ActivityThread(26767):    at dalvik.system.NativeStart.main(Native Method)
05-17 14:58:53.010: E/ActivityThread(26767): Caused by: java.lang.reflect.InvocationTargetException
05-17 14:58:53.010: E/ActivityThread(26767):    at java.lang.reflect.Constructor.constructNative(Native Method)
05-17 14:58:53.010: E/ActivityThread(26767):    at java.lang.reflect.Constructor.newInstance(Constructor.java:415)
05-17 14:58:53.010: E/ActivityThread(26767):    at android.view.LayoutInflater.createView(LayoutInflater.java:505)
05-17 14:58:53.010: E/ActivityThread(26767):    ... 21 more
05-17 14:58:53.010: E/ActivityThread(26767): Caused by: java.lang.NoSuchMethodError: android.widget.LinearLayout.<init>
05-17 14:58:53.010: E/ActivityThread(26767):    at com.example.customviews.CustomView.<init>(CustomView.java:98)
05-17 14:58:53.010: E/ActivityThread(26767):    at com.example.customviews.CustomView.<init>(CustomView.java:94)
05-17 14:58:53.010: E/ActivityThread(26767):    ... 24 more

我不明白是什么导致了调用 super(context, attrs, defStyle) 时出现 InflateException。我还尝试了 super(context, attrs, 0)，但这并没有帮助，这真的很奇怪，因为即使是 LinearLayout 也使用它，就像我检查过其源代码的大多数其他 View 一样。

Answer 1

我在 Android Developers Google Group 上找到了这个答案:

The three-argument version of LinearLayout constructor is only available with API 11 and higher -- i.e. Android 3.0.

This dependency has to be satisfied at runtime by the actual Android version running on the device.

我在运行 Gingerbread (2.3.3) 的手机上进行测试。果然，当我在带有 ICS (4.0.3) 的模拟器上运行该程序时，它运行良好。仍在寻找解决方法，以便我可以在 Honeycomb 之前使用我的代码。