android - onCreate savedInstanceState Bundle 中的 FragmentActivity NullPointer

Question

如果我将应用置于后台并在一段时间后恢复它，我会收到以下异常。
如果我更改方向或背景并立即恢复应用程序(onSaveInstanceState 和 onCreate 在这两种情况下都执行)，则 savedInstanceState Bundle 包含正确的 ArrayList 并且一切正常。

02-05 14:42:06.254 E/AndroidRuntime(24355): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.savant.donordetailsviewpagertitle/com.savant.donordetailsviewpagertitle.activities.DonorDetailsContainerFragmentActivity}: java.lang.NullPointerException: expected receiver of type com.savant.donordetailsviewpagertitle.activities.DonorDetailsContainerFragmentActivity$RunningLoadersList, but got null

    private class RunningLoadersList extends ArrayList<RunningLoader> implements
        Parcelable {

    private static final long   serialVersionUID    = 663585476779879096L;

    public RunningLoadersList() {
    }

    @SuppressWarnings("unused")
    public RunningLoadersList(Parcel in) {
        this();
        readFromParcel(in);
    }

    private void readFromParcel(Parcel in) {

        this.clear();

        // First we have to read the list size
        int size = in.readInt();

        for (int i = 0; i < size; i++) {
            RunningLoader r = new RunningLoader(in.readInt(),
                    in.readBundle());
            this.add(r);
        }
    }

    public int describeContents() {
        return 0;
    }

    public final Parcelable.Creator<RunningLoadersList> CREATOR = new Parcelable.Creator<RunningLoadersList>() {
                                                                    public RunningLoadersList createFromParcel(Parcel in) {
                                                                        return new RunningLoadersList(in);
                                                                    }

                                                                    public RunningLoadersList[] newArray(int size) {
                                                                        return new RunningLoadersList[size];
                                                                    }
                                                                };

    public void writeToParcel(Parcel dest, int flags) {
        int size = this.size();

        // We have to write the list size, we need him recreating the list
        dest.writeInt(size);

        for (int i = 0; i < size; i++) {
            RunningLoader r = this.get(i);

            dest.writeInt(r.id);
            dest.writeBundle(r.args);
        }
    }
}

static final class RunningLoader {
    private final int       id;
    private final Bundle    args;

    RunningLoader(int _id, Bundle _args) {
        id = _id;
        args = _args;
    }
}



    @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // This has to be called before setContentView and you must use the
    // class in android.support.v4.view and NOT android.view
    requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);

    setContentView(R.layout.main);

    Log.d(LOG_TAG, "onCreate");

    mAdapter = new ViewPagerTitleAdapter(getSupportFragmentManager());

    mPager = (ViewPager) findViewById(R.id.pager);
    mPager.setAdapter(mAdapter);

    TabPageIndicator indicator = (TabPageIndicator) findViewById(R.id.tabindicator);
    indicator.setViewPager(mPager);

    // first check if we already have a running loader
    if ((savedInstanceState != null)
            && savedInstanceState.containsKey("RUNNING_LOADERS")) {
        mRunningLoaders = savedInstanceState.getParcelable("RUNNING_LOADERS");
    }

    if (mRunningLoaders == null) {
        mRunningLoaders = new RunningLoadersList();
    }

    if (mRunningLoaders != null) {
        for (int i = 0; i < mRunningLoaders.size(); i++) {
            StartLoader(mRunningLoaders.get(i).id,
                    mRunningLoaders.get(i).args);
        }
    }

    if (getSupportLoaderManager().hasRunningLoaders()) {
        setProgressBarIndeterminateVisibility(Boolean.TRUE);
    } else {
        setProgressBarIndeterminateVisibility(Boolean.FALSE);
    }
}


    @Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putParcelable("RUNNING_LOADERS", mRunningLoaders);

    Log.d(LOG_TAG, "onSaveInstanceState");
}

Answer 1

Parcelable.Creator<RunningLoadersList>()必须是 static像这样

public static final Parcelable.Creator<RunningLoadersList> CREATOR = 
new Parcelable.Creator<RunningLoadersList>() {
...
...
.
}