我怀疑我内部有一个活动，即有三个片段，即a，b，c交易将像a-＆gt; b-＆gt;。我的疑问是当我从b输入后退按钮它必须去片段a和frag b应该返回到其默认状态我该如何实现它？我真的很困惑，因为我是新手，我希望你们在这里帮忙
这是我的片段代码：
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ListView;
import java.util.ArrayList;
public class Leads extends Fragment implements View.OnClickListener {
public Leads(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_one, container, false);
ArrayList<NewsItem> listContact = GetlistContact();
ListView lv = (ListView) rootView.findViewById(R.id.listView);
lv.setAdapter(new CustomListAdapter(getActivity(), listContact));
return rootView;
}
private ArrayList<NewsItem> GetlistContact(){
ArrayList<NewsItem> contactlist = new ArrayList<NewsItem>();
NewsItem contact = new NewsItem();
for(int i=1;i<=30;i++) {
contact = new NewsItem();
contact.setHeadline("Yoge " +i);
contact.setReporterName("Yogeshwaran" + i);
contact.setLeadsource("Yogan" + i);
contact.setLeadStatus("open" + i);
contact.setLeadType("Business"+i);
contactlist.add(contact);
}
return contactlist;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Fragment fragment=null;
Button add = (Button) getActivity().findViewById(R.id.btnadd);
add.setOnClickListener(this);
ImageButton filter = (ImageButton) getActivity().findViewById(R.id.btnfilter);
filter.setOnClickListener(this);
}
String str="";
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.btnadd:
Fragment newFragment = new Add();
str="add";
// consider using Java coding conventions (upper first char class names!!!)
FragmentTransaction transaction = getFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.content_frame, newFragment,str);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
}
}
}
这是我的frag b代码：
package first.service.precision.servicefirst;
/**
* Created by 4264 on 23-11-2015.
*/
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Spinner;
import android.widget.TextView;
import java.util.ArrayList;
/**
* Created by 4264 on 16-10-2015.
*/
public class Add extends Fragment implements View.OnClickListener {
public static ListView lv;
static String sbu, sbuu, sc, ssc, req;
static String bu;
customListAdapterldrequirements customListAdapterldrequirements;
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
try {
View rootView = inflater.inflate(R.layout.activity_btn_add, container, false);
Spinner ldsource = (Spinner) rootView.findViewById(R.id.lead_source);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
getActivity().getBaseContext(), R.array.dropbox1, R.layout.spinnerlayout);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
ldsource.setAdapter(adapter);
// EditText editText=(EditText)rootView.findViewById(R.id.title);
Spinner ldtype = (Spinner) rootView.findViewById(R.id.ldtype);
ArrayAdapter<CharSequence> adapter1 = ArrayAdapter.createFromResource(
getActivity().getBaseContext(), R.array.dropbox2, R.layout.spinnerlayout);
adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
ldtype.setAdapter(adapter1);
Spinner ldstatus = (Spinner) rootView.findViewById(R.id.ldstatus);
TextView txt = (TextView) rootView.findViewById(R.id.spinnerTarget);
ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(
getActivity().getBaseContext(), R.array.dropbox3, R.layout.spinnerlayout);
adapter2.setDropDownViewResource(android.R.layout.simple_selectable_list_item);
ldstatus.setAdapter(adapter2);
// Bundle bundle=getArguments();
// String good=bundle.getString("sbu");
Bundle bundle = getArguments();
// sbu = getArguments().getString("yes");
ArrayList<LdNewsItem> listContact = GetlistContact();
// public boolean onTouch(View v, MotionEvent event) {
// return false;
// }
// Setting on Touch Listener for handling the touch inside ScrollView
//});
lv = (ListView) rootView.findViewById(R.id.ldrequirements);
customListAdapterldrequirements = new customListAdapterldrequirements(getActivity(), listContact);
lv.setAdapter(customListAdapterldrequirements);
// customListAdapterldrequirements customListAdapterldrequirements=new customListAdapterldrequirements(getActivity(),listContact);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
NewRequirements newRequirements = new NewRequirements();
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
// lv.deferNotifyDataSetChanged();
ft.replace(R.id.content_frame, newRequirements, "hi");
ft.addToBackStack(null);
ft.commit();
}
});
/* lv.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return false;
}
// Setting on Touch Listener for handling the touch inside ScrollView
// @Override
// public boolean onTouch(View v, MotionEvent event) {
// Disallow the touch request for parent scroll on touch of child view
// v.getParent().requestDisallowInterceptTouchEvent(true);
//
// return false;
// }
});*/
return rootView;
} catch (Exception e) {
throw e;
}
}
public void updateListView() {
customListAdapterldrequirements.notifyDataSetChanged();
}
private ArrayList<LdNewsItem> GetlistContact() {
ArrayList<LdNewsItem> contactlist = new ArrayList<LdNewsItem>();
// String str=getArguments().getString("yes");
sbu = Main2Activity.sbu;
bu = Main2Activity.bu;
sbuu = Main2Activity.sbuu;
sc = Main2Activity.sc;
ssc = Main2Activity.ssc;
req = Main2Activity.req;
for (int i = 1; i <= 5; i++) {
LdNewsItem contact = new LdNewsItem();
contact.setSbu(sbu);
contact.setBu(bu);
contact.setSbuu(sbuu);
contact.setSc(sc);
contact.setSsc(ssc);
contact.setReq(req);
// contact.setReporterName("No matter how big your house is, how recent your car is, or how big your bank account is — our graves will always be the same size. Stay humble." + i);
contactlist.add(contact);
//lv.setAdapter((ListAdapter) contactlist);
}
return contactlist;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Fragment fragment = null;
setHasOptionsMenu(true);
Button btnrequirements = (Button) getActivity().findViewById(R.id.btnrequirements);
btnrequirements.setOnClickListener(this);
Button btnactnt = (Button) getActivity().findViewById(R.id.btnacnt);
btnactnt.setOnClickListener(this);
Button btnprimary = (Button) getActivity().findViewById(R.id.btnprimary);
btnprimary.setOnClickListener(this);
Button btnsecondary = (Button) getActivity().findViewById(R.id.btnsecondary);
btnsecondary.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.btnrequirements:
Fragment newFragment = new NewRequirements();
// consider using Java coding conventions (upper first char class names!!!)
FragmentTransaction transaction = getFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.content_frame, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
break;
case R.id.btnacnt:
FragmentManager fm = getFragmentManager();
//FragmentTransaction ft=fm.beginTransaction();
SelectAccountDialog selectAccountDialog = new SelectAccountDialog();
selectAccountDialog.setRetainInstance(true);
selectAccountDialog.show(fm, "fragment_name");
//ft.addToBackStack(null);
break;
case R.id.btnprimary:
FragmentManager fmm = getFragmentManager();
// FragmentTransaction ftt=fmm.beginTransaction();
SelectAccountDialog selectAccountDialog1 = new SelectAccountDialog();
selectAccountDialog1.setRetainInstance(true);
selectAccountDialog1.show(fmm, "fragment_name");
// ftt.addToBackStack(null);
break;
case R.id.btnsecondary:
FragmentManager fm2 = getFragmentManager();
// FragmentTransaction fttt=fm2.beginTransaction();
SelectAccountDialog selectAccountDialog2 = new SelectAccountDialog();
selectAccountDialog2.setRetainInstance(true);
selectAccountDialog2.show(fm2, "fragment_name");
// fttt.addToBackStack(null);
break;
}
}
/*@Override
public void onDestroyView() {
// TODO Auto-generated method stub
super.onDestroyView();
Leads leads=new Leads();
FragmentManager back=getFragmentManager();
FragmentTransaction ft=back.beginTransaction();
ft.replace(R.id.content_frame,leads);
ft.addToBackStack(null);
ft.commit();
}*/
}
我的活动如下：
package first.service.precision.servicefirst;
import android.annotation.SuppressLint;
import android.app.ActionBar;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.util.Log;
import android.view.Gravity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
public class Main2Activity extends Activity {
public static String sbu,bu,sbuu,sc,ssc,req;
// Within which the entire activity is enclosed
private DrawerLayout mDrawerLayout;
// ListView represents Navigation Drawer
private ListView mDrawerList;
Button butonlead;
// ActionBarDrawerToggle indicates the presence of Navigation Drawer in the action bar
private ActionBarDrawerToggle mDrawerToggle;
// Title of the action bar
private String mTitle = "";
@SuppressLint("NewApi")
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
final ActionBar ab = getActionBar();
ab.show();
// Getting reference to the DrawerLayout
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
ab.setTitle(mTitle);
mDrawerList = (ListView) findViewById(R.id.drawer_list);
// Getting reference to the ActionBarDrawerToggle
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
R.string.open_drawer,
R.string.close_drawer) {
/** Called when drawer is closed */
public void onDrawerClosed(View view) {
invalidateOptionsMenu();
}
/** Called when a drawer is opened */
public void onDrawerOpened(View drawerView) {
invalidateOptionsMenu();
}
};
// Setting DrawerToggle on DrawerLayout
mDrawerLayout.setDrawerListener(mDrawerToggle);
// Creating an ArrayAdapter to add items to the listview mDrawerList
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getApplication(),
R.layout.drawer_list_item, R.id.title, getResources().getStringArray(R.array.option));
// Setting the adapter on mDrawerList
mDrawerList.setAdapter(adapter);
// Enabling Home button
ab.setHomeButtonEnabled(true);
ab.setBackgroundDrawable(new ColorDrawable(Color.parseColor("#53A93F")));
// Enabling Up navigation
ab.show();
ab.setDisplayHomeAsUpEnabled(true);
// Setting item click listener for the listview mDrawerList
mDrawerList.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// Getting an array of options
String[] menuItems = getResources().getStringArray(R.array.option);
// Currently selected option
mTitle = menuItems[position];
Fragment fragment = null;
String tag="";
switch (position) {
case 0:
fragment = new Leads();
tag="leads";
break;
case 1:
fragment = new Opportunities();
break;
case 2:
fragment = new Accounts();
break;
case 3:
fragment = new Contactss();
break;
case 4:
fragment = new Documents();
break;
case 5:
fragment = new Reports();
default:
break;
}
if (fragment != null) {
// Getting reference to the FragmentManager
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment,tag).addToBackStack("fragback").commit();
// Creating a fragment transaction
FragmentTransaction ft = fragmentManager.beginTransaction();
// Adding a fragment to the fragment transaction
ft.replace(R.id.content_frame, fragment);
// Committing the transaction
ft.commit();
// Closing the drawer
mDrawerLayout.closeDrawer(mDrawerList);
} else {
// error in creating fragment
Log.e("MainActivity", "Error in creating fragment");
}
}
});
}
@Override
public void onBackPressed() {
if (mDrawerLayout.isDrawerOpen(Gravity.LEFT)) {
mDrawerLayout.closeDrawer(mDrawerList);
} else {
FragmentManager manager = getFragmentManager();
manager.popBackStack();
super.onBackPressed();
}
}
public void changeFragment(Fragment fragment, String tag, boolean shouldAddToBackStack) {
try {
FragmentTransaction ft = getFragmentManager().beginTransaction();
if (shouldAddToBackStack)
ft.addToBackStack(tag);
else {
getFragmentManager().popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
}
ft.replace(R.id.content_frame, fragment, tag)
.commit();
getFragmentManager().executePendingTransactions();
} catch (Exception ex) {
ex.printStackTrace();
}
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
mDrawerToggle.syncState();
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* Called whenever we call invalidateOptionsMenu()
*/
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the drawer is open, hide action items related to the content view
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main2, menu);
return super.onCreateOptionsMenu(menu);
}
/* @Override
public void DataTransfer(String e) {
}*/
//
// @Override
// public void DataTransfer(ArrayList<String> e) {
// Add obj=(Add)getFragmentManager().findFragmentById(R.id.frag_1);
// obj.GetlistContact(e);
// }
}
/* @Override
public void selectedvalue(String s) {
Add add=new Add();
FragmentManager fm=getFragmentManager();
FragmentTransaction ft=fm.beginTransaction();
ft.replace(R.id.content_frame,add);
ft.commit();}
}
*/
答案 0 :(得分：0)
你的应用程序只有一个backstack。它是一个堆栈，如果我们将我们的片段添加到这个堆栈，按下后退按钮它会弹出。在您的情况下，您可以添加以下代码来切换片段。在主要活动和父片段中输入此代码。将shouldAddToBackStack传递为true，您要在backstack中添加哪些片段，一旦按下后退按钮，它将自动弹出
你应该替换所有这些
Fragment newFragment = new NewRequirements();
// consider using Java coding conventions (upper first char class names!!!)
FragmentTransaction transaction = getFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.content_frame, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
使用此功能
public void changeFragment(Fragment fragment, String tag, boolean shouldAddToBackStack) {
try {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
if (shouldAddToBackStack)
ft.addToBackStack(tag);
else {
getActivity().getSupportFragmentManager().popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);
}
ft.replace(R.id.container, fragment, tag)
.commit();
getActivity().getSupportFragmentManager().executePendingTransactions();
} catch (Exception ex) {
ex.printStackTrace();
}
}
答案 1 :(得分：0)
当您将第二个片段添加到活动时，将第一个片段添加到后台堆栈：
fragmentTransaction.addToBackStack("fragmentATag");
还会覆盖活动的onBackPressed（）方法：
@Override
public void onBackPressed() {
FragmentManager manager = getSupportFragmentManager();
if (manager.getBackStackEntryCount() > 0)
manager.popBackStack();
}
答案 2 :(得分：0)
编写getActivity（）。getFragmentManager（）。popBackStack（）;在onBackPressedMethod（）
答案 3 :(得分：0)
你可以这样做：
通过以下代码替换 片段：
android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
android.support.v4.app.FragmentTransaction ft = fragmentManager.beginTransaction();
ft.replace(R.id.content_view, new FragmentB());
ft.addToBackStack(null);
ft.commit();
无需在片段B 中执行代码以返回片段A ，它将自动处理，当您按硬背键时，如果您想从片段B 添加自定义按钮 片段A ，而不是必须添加 getActivity.onBackPressed（）。
希望这会对你有所帮助。