如何附加()和detach()而不是add()和remove()来保存片段视图
我有ActionBar
的以下代码:
private class MyTabListener implements ActionBar.TabListener { private Fragment mFragment; private final Activity mActivity; private final String mFrag; public MyTabListener( Activity activity, String fragName ) { mActivity = activity; mFrag = fragName; } @Override public void onTabReselected( Tab tab, FragmentTransaction ft ) { // TODO Auto-generated method stub } @Override public void onTabSelected( Tab tab, FragmentTransaction ft ) { mFragment = Fragment.instantiate( mActivity, mFrag ); ft.add( android.R.id.content, mFragment ); } @Override public void onTabUnselected( Tab tab, FragmentTransaction ft ) { ft.remove( mFragment ); mFragment = null; } }
我在这些Tab
片段中有一些文本框,并且在选项卡之间切换会强制应用程序丢失我添加到这些文本框中的任何数据。 我想使用attach
和detach
来保存片段状态,而不是add
和remove
。
如何在我已有的代码中实现这一目标?
更新 :
代码现在看起来像这样:
private class MyTabListener implements ActionBar.TabListener { private Fragment mFragment; private final Activity mActivity; private final String mFrag; public MyTabListener( Activity activity, String fragName ) { mActivity = activity; mFrag = fragName; } @Override public void onTabReselected( Tab tab, FragmentTransaction ft ) { // TODO Auto-generated method stub } @Override public void onTabSelected( Tab tab, FragmentTransaction ft ) { //mFragment = Fragment.instantiate( mActivity, mFrag ); //ft.add( android.R.id.content, mFragment ); mFragment = mActivity.getSupportFragmentManager().findFragmentByTag(mFrag); if( mFragment == null ) { mFragment = Fragment.instantiate(mActivity, mClass.getName()); ft.add(android.R.id.content, mFragment, mFrag); } else { ft.attach(mFragment); } } @Override public void onTabUnselected( Tab tab, FragmentTransaction ft ) { //ft.remove( mFragment ); //mFragment = null; if (mFragment != null) { ft.detach(mFragment); } } }
我收到以下行的错误:
mFragment = mActivity.getSupportFragmentManager().findFragmentByTag(mFrag);
错误:
The method getSupportFragmentManager() is undefined for the type Activity
您可以使用SharedPreferences
临时存储显示的变量,而不是重写代码。
在您要离开的选项卡的onDestroy
方法中,只需将变量添加到首选项中,并在重新进入选项卡时检索它们。
@Override public void onDestroy(){ super.onDestroy(); Log.i("OnDestroy", "Logged"); SharedPreferences prefs = getActivity().getSharedPreferences("name", Context.MODE_PRIVATE); Editor editor = prefs.edit(); editor.putString("stringName", stringToStore); editor.commit(); }