Java Eclipse可以'；找不到扩展视图类

我正在尝试实现一个定制：它将完全相同，只是在用户登录后它将具有额外的功能；我不想改变它的风格或任何与它的外观/感觉有关的东西

需要在xml文件中显式调用该按钮：

<com.facebook.widget.LoginButton
        android:id="@+id/login_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="30dp"
        android:layout_marginBottom="30dp" />

现在，据我所知，我应该按如下方式调用我的按钮（我正是这样做的）：

---

Nope的可能重复：尝试了它，但仍然得到完全相同的错误。您到底尝试了什么？注意到我没有执行“$”并重试。解决了这个错误，但现在我无法将其强制转换到我的类（当我尝试在Java代码中强制转换它时，我得到了ClassCastException错误）。解决办法？

public class CustomFBButton extends LoginButton{

    public CustomFBButton (Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void enablePublishActions(final Activity activity) {
                 //EXTRA FUNCTIONALITY
    }
}

<com.company.helpers.FacebookClass.CustomFBButton
        android:id="@+id/login_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="30dp"
        android:layout_marginBottom="30dp" />

04-24 16:11:00.899: E/AndroidRuntime(28004): FATAL EXCEPTION: main
04-24 16:11:00.899: E/AndroidRuntime(28004): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.company.product.main/com.company.product.settings.Settings}: android.view.InflateException: Binary XML file line #30: Error inflating class com.company.helpers.FacebookClass.CustomFBButton
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2305)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2359)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.ActivityThread.access$700(ActivityThread.java:165)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1326)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.os.Handler.dispatchMessage(Handler.java:99)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.os.Looper.loop(Looper.java:137)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.ActivityThread.main(ActivityThread.java:5455)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at java.lang.reflect.Method.invokeNative(Native Method)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at java.lang.reflect.Method.invoke(Method.java:525)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at dalvik.system.NativeStart.main(Native Method)
04-24 16:11:00.899: E/AndroidRuntime(28004): Caused by: android.view.InflateException: Binary XML file line #30: Error inflating class com.company.helpers.FacebookClass.CustomFBButton
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:713)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:761)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.rInflate(LayoutInflater.java:769)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.inflate(LayoutInflater.java:498)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.inflate(LayoutInflater.java:398)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.inflate(LayoutInflater.java:354)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:361)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at com.actionbarsherlock.internal.ActionBarSherlockNative.setContentView(ActionBarSherlockNative.java:133)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at com.actionbarsherlock.app.SherlockActivity.setContentView(SherlockActivity.java:229)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at com.company.product.settings.Settings.onCreate(Settings.java:34)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.Activity.performCreate(Activity.java:5372)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2267)
04-24 16:11:00.899: E/AndroidRuntime(28004):    ... 11 more
04-24 16:11:00.899: E/AndroidRuntime(28004): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.company.helpers.FacebookClass.CustomFBButton" on path: /data/app/com.company.product.main-2.apk
04-24 16:11:00.899: E/AndroidRuntime(28004):    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:64)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.createView(LayoutInflater.java:565)
04-24 16:11:00.899: E/AndroidRuntime(28004):    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:702)