我有一个名为"MeinProfilFragment"的片段。还有一个处理 ActionBar-Tabs 逻辑的 MainActivity。
在“MeinProfilFragment”中，我放置了“Login-Process”的逻辑。
用户成功登录后，我想显示另一个布局。
怎么做 ？可以在 Fragment 中替换 Fragment吗？还是我必须为 UI-Updates 调用 MainActivity ？
这是“MainActivity”的代码：
public class MainActivity extends Activity {
public static int selectedTab;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowHomeEnabled(false);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setDisplayShowCustomEnabled(false);
Tab meinProfil = actionBar.newTab().setText("Mein Profil");
TabListener<MeinProfilFragment> tabListenerMeinProfil = new TabListener<MeinProfilFragment>(this,"Mein Profil",MeinProfilFragment.class);
meinProfil.setTabListener(tabListenerMeinProfil);
actionBar.addTab(meinProfil);
Tab mitglieder = actionBar.newTab().setText("Mitglieder");
TabListener<MitgliederFragment> tabListenerMitglieder = new TabListener<MitgliederFragment>(this,"Mitglieder",MitgliederFragment.class);
mitglieder.setTabListener(tabListenerMitglieder);
actionBar.addTab(mitglieder);
Tab dinner = actionBar.newTab().setText("Dinner");
TabListener<DinnerFragment> tabListenerDinner = new TabListener<DinnerFragment>(this,"Dinner",DinnerFragment.class);
dinner.setTabListener(tabListenerDinner);
actionBar.addTab(dinner);
Tab community = actionBar.newTab().setText("Community");
TabListener<CommunityFragment> tabListenerCommunity = new TabListener<CommunityFragment>(this,"Community",CommunityFragment.class);
community.setTabListener(tabListenerCommunity);
actionBar.addTab(community);
if(savedInstanceState != null){
actionBar.setSelectedNavigationItem(savedInstanceState.getInt("selectedTab"));
}
}
private static class TabListener<T extends Fragment> implements ActionBar.TabListener
{
private Fragment mFragment;
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
public TabListener(Activity activity,String tag,Class<T> clz) {
mActivity = activity;
mTag = tag;
mClass = clz;
}
@Override
public void onTabSelected(Tab tab, FragmentTransaction ft) {
selectedTab = tab.getPosition();
Fragment prevFragment;
FragmentManager fm = mActivity.getFragmentManager();
prevFragment = fm.findFragmentByTag(mTag);
if (prevFragment != null) {
mFragment = prevFragment;
}
if(mFragment == null){
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment,mTag);
}else{
ft.attach(mFragment);
}
}
@Override
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
selectedTab = tab.getPosition();
if(mFragment != null){
ft.detach(mFragment);
}else{
mFragment = Fragment.instantiate(mActivity, mClass.getName());
ft.add(android.R.id.content, mFragment,mTag);
}
}
@Override
public void onTabReselected(Tab tab, FragmentTransaction ft) {
selectedTab = tab.getPosition();
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("selectedTab", selectedTab);
}
这是 MeinProfilFragment：
public class MeinProfilFragment extends Fragment implements OnClickListener{
EditText LoginEmail;
EditText LoginPassw;
Button LoginButton;
public boolean loggedIn = false;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.mein_profil_fragment,container, false);
LoginEmail = (EditText) view.findViewById(R.id.login_email_input);
LoginPassw = (EditText) view.findViewById(R.id.login_passwort_input);
LoginButton = (Button) view.findViewById(R.id.login_submit);
LoginButton.setOnClickListener(this);
return view;
}
@Override
public void onClick(View arg0) {
switch(arg0.getId())
{
case R.id.login_submit:
// Get Input Values:
String login_email = LoginEmail.getText().toString();
String login_passw = LoginPassw.getText().toString();
if(login_email.length()<6 || login_passw.length()<4){
return;
}
Log.i("TEST","onClick: E-Mail: "+login_email+" \n Passwort: "+login_passw);
new Login().execute(login_email,login_passw);
break;
}
}
private class Login extends AsyncTask<String,Void,JSONObject>
{
@Override
protected JSONObject doInBackground(String... params) {
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost("xxxx");
try{
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("mitglied_email",params[0]));
nameValuePairs.add(new BasicNameValuePair("mitglied_passwort",params[1]));
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpClient.execute(httpPost);
HttpEntity entity = response.getEntity();
InputStream is = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
String line = reader.readLine();
JSONObject jsonData = new JSONObject(line);
return jsonData;
}catch(Exception e){
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
updateUi(result);
}
}
public void updateUi(JSONObject result)
{
try {
Log.i("TEST",result.getString("logged_in"));
String loggedInFlag = result.getString("logged_in");
if(loggedInFlag.equals("true")){
// Richtige Angaben:
Log.i("TEST","loggedInFlag EQ TRUE");
loggedIn = true;
// Here i want to replace this current fragment with another called e.g "ProfileFragment"
}else{
// Falsche Angaben:
Log.i("TEST","loggedInFlag EQ FALSE");
loggedIn = false;
}
} catch (JSONException e) {
e.printStackTrace();
}
}
在updateUi()方法中，我想显示/膨胀另一个 UI。
怎么做 ？有没有办法“重新启动”片段，然后在 onCreateView() 中膨胀另一个片段布局。
或者可以将 Fragment-Layout 替换为 Fragment 中的另一个 Fragment-Layout ？
最佳做法是什么？