Question

当活动被销毁并重新打开时，恢复微调器状态，在textViews等中输入的文本的最佳方法是什么？

编辑：这里是我的一些代码，当再次调用onCreate时，如何在writeText中输入任何文本？

SharedPreferences sh_Pref;
SharedPreferences.Editor toEdit;

    @Override
public void onDestroy() {
    sharedPrefernces();
    super.onDestroy();
}

    public void sharedPrefernces() {

    sh_Pref = getSharedPreferences("SavedConfig", MODE_PRIVATE);
    toEdit = sh_Pref.edit();
    toEdit.putString("Text", writeText.getText().toString());
    toEdit.commit();

}

Answer 1

如果为textView设置唯一标识符，则活动将自动保存该元素的状态。出于其他目的，您应该覆盖onSavedInstanceState()方法

Answer 2

我尝试了很多东西，但是这个是我发现并使用过几次的最好的方法。用例子清楚地说明了，在this帖子

中精美地解释了

public class MainFragment extends StatedFragment {

...

/**
 * Save Fragment's State here
 */
@Override
protected void onSaveState(Bundle outState) {
    super.onSaveState(outState);
    // For example:
    //outState.putString("text", tvSample.getText().toString());
}

/**
 * Restore Fragment's State here
 */
@Override
protected void onRestoreState(Bundle savedInstanceState) {
    super.onRestoreState(savedInstanceState);
    // For example:
    //tvSample.setText(savedInstanceState.getString("text"));
}

...

}

还提供片段模板以便更好地理解

   import android.os.Bundle;
   import android.support.v4.app.Fragment;
   import android.view.LayoutInflater;
   import android.view.View;
   import android.view.ViewGroup;

   import com.inthecheesefactory.thecheeselibrary.R;

   /**
   * Created by nuuneoi on 11/16/2014.
   */
public class StatedFragment extends Fragment {

Bundle savedState;

public StatedFragment() {
    super();
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    // Restore State Here
    if (!restoreStateFromArguments()) {
        // First Time, Initialize something here
        onFirstTimeLaunched();
    }
}

protected void onFirstTimeLaunched() {

}

@Override
public void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    // Save State Here
    saveStateToArguments();
}

@Override
public void onDestroyView() {
    super.onDestroyView();
    // Save State Here
    saveStateToArguments();
}

////////////////////
// Don't Touch !!
////////////////////

private void saveStateToArguments() {
    if (getView() != null)
        savedState = saveState();
    if (savedState != null) {
        Bundle b = getArguments();
        b.putBundle("internalSavedViewState8954201239547", savedState);
    }
}

////////////////////
// Don't Touch !!
////////////////////

private boolean restoreStateFromArguments() {
    Bundle b = getArguments();
    savedState = b.getBundle("internalSavedViewState8954201239547");
    if (savedState != null) {
        restoreState();
        return true;
    }
    return false;
}

/////////////////////////////////
// Restore Instance State Here
/////////////////////////////////

private void restoreState() {
    if (savedState != null) {
        // For Example
        //tv1.setText(savedState.getString("text"));
        onRestoreState(savedState);
    }
}

protected void onRestoreState(Bundle savedInstanceState) {

}

//////////////////////////////
// Save Instance State Here
//////////////////////////////

private Bundle saveState() {
    Bundle state = new Bundle();
    // For Example
    //state.putString("text", tv1.getText().toString());
    onSaveState(state);
    return state;
}

protected void onSaveState(Bundle outState) {

}
}

如何在活动被破坏android时保存/恢复视图状态？

2 个答案: