當活動銷毀android時，如何保存/恢復視圖狀態？

Question

銷毀並重新打開活動后，恢復微調器狀態，在textViews中輸入的文本等的最佳方法是什么？

編輯：這是我的一些代碼，當再次調用onCreate時，如何使在writeText中輸入的任何文本都在那里？

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

如果您為textView設置了唯一標識符，活動性將自動保存該元素的狀態。 出於其他目的，您應該覆蓋onSavedInstanceState()方法

Answer 2

我嘗試了很多事情，但這是我發現並使用過幾次的最佳方法。通過示例顯示清晰的事情，在這篇文章中很好地解釋了

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"));
}

...

}

還提供片段模板以供更好地理解

   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) {

}
}