Android IllegalArgumentException：如果应用程序在后台运行了一段时间,则状态类错误

我认为这是由于我设置了应用背景而导致的内存不足.
日志如下：

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.qingdaonews.bus/com.qingdaonews.activity.RealTime}: 
java.lang.IllegalArgumentException: Wrong state class, expecting View State but received class android.view.View$BaseSavedState instead. This usually happens when two views of different type have the same id in the same hierarchy. This view's id is id/myviewpager. Make sure other views do not use the same id.
    at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:2266)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316)
    at android.app.ActivityThread.access$600(ActivityThread.java:150)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1298)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:213)
    at android.app.ActivityThread.main(ActivityThread.java:5225)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:525)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
    at dalvik.system.NativeStart.main(Native Method)

看起来由于视图的ID相同.实际上,ID’myviewpager’在xml文件中仅出现一次,并且仅在从后台重新打开应用程序时才会出现问题.

我的MainActivity有一个可以替换的片段.我使用getSupportFragmentManager().beginTransaction().replace(R.id.content_frame,fragment).commit();
当我开始活动时.
没有’savedInstanceState’的超级方法,我没有使用其他东西.

解决方法:

原因是您的片段被重新添加.
您的代码如下所示：

protected void onCreate(Bundle savedInstanceState){
    super(savedInstanceState);        
    ///...
    getSupportFragmentManager().beginTransaction()
        .replace(R.id.content_frame, fragment).commit();
}

如果通过调用super(savedInstanceState)的saveInstanceState！= null可以恢复关联的FragmentManager,并且所有提交的片段也都可以恢复.相反,请检查您的片段是否已添加,并仅在未添加时添加它：

public class MyActivity extends Activity{

    private MyFragment myFragment;//extends Fragment

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //your stuff
        FragmentManager fm = getFragmentManager();
        myFragment = (MyFragment) fm.findFragmentByTag(MyFragment.TAG);
        if(myFragment == null){
            myFragment = new MyFragment();
            fm.beginTransaction()
                .add(R.id.content_frame, myFragment, MyFragment.TAG)
                .commit();
         }
        //other stuff
    }
}

在您的MyFragment中,TAG是：
公共静态最终字符串TAG = MyFragment.class.getSimpleName();

对于我来说,我发现添加带有TAG参数的片段是一个很好的做法.