我有4个Fragment Sector1,2,3,4，我想在Fragment之间传输数据。 当我在扇区1中添加产品时，相同的产品将插入Sector2中的Edit中。 如果我在扇区1和2之间切换没问题，但是当我转到Sector3并返回到扇区1以插入另一个产品时，新产品不会出现在Sector2上的Edit中。 为什么？ （这是第一个问题），我在Sector 1和Sector3之间实现了相同的共享数据，但没有添加任何产品为什么？ （这是第二个问题）
这里是文件：
public class MainActivity extends FragmentActivity implements ActionBar.TabListener,
OnShareMyDataListener{
private static final String TAG = "MainActivity";
AppSectionsPagerAdapter mAppSectionsPagerAdapter;
ViewPager mViewPager;
public void onCreate(Bundle savedInstanceState) {
Log.d(TAG, "MainActivity.onCreate");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Settare il tipo di navigazione
mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(getSupportFragmentManager());
final ActionBar actionBar = getActionBar();
actionBar.setHomeButtonEnabled(false);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
mViewPager = (ViewPager) findViewById(R.id.pager);
mViewPager.setAdapter(mAppSectionsPagerAdapter);
mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
@Override
public void onPageSelected(int position) {
actionBar.setSelectedNavigationItem(position);
}
});
// creo icona e scritta per il 1 Tab
Tab tab = actionBar.newTab()
.setText("Ordine")
.setTabListener(this)
.setIcon(R.drawable.ic_menu_agenda);
actionBar.addTab(tab);
// creo icona e scritta per il 2 Tab
tab = actionBar.newTab()
.setText("by Mail")
.setTabListener(this)
.setIcon(R.drawable.ic_menu_send);
actionBar.addTab(tab);
// creo icona e scritta per il 3 Tab
tab = actionBar.newTab()
.setText("by SMS")
.setTabListener(this)
.setIcon(R.drawable.phone);
actionBar.addTab(tab);
// creo icona e scritta per il 4 Tab
tab = actionBar.newTab()
.setText("Feedback")
.setTabListener(this)
.setIcon(R.drawable.ic_menu_revert);
actionBar.addTab(tab);
}
@Override
public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
@Override
public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
mViewPager.setCurrentItem(tab.getPosition());
}
@Override
public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
}
public class AppSectionsPagerAdapter extends FragmentPagerAdapter {
public AppSectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
// Il return new chiama le altre classi (i Fragment)
@Override
public Fragment getItem(int i) {
switch (i) {
case 0:
return new Sector1();
case 1:
return new Sector2();
case 2:
return new Sector3();
case 3:
return new Sector4();
default:
Fragment fragment = new Sector1();
Bundle args = new Bundle();
fragment.setArguments(args);
return fragment;
}
}
// Settare il titolo dei Sector
@Override
public int getCount() {
return 4;
}
}
@Override
public void onShareMyData(ArrayList<User> data) {
// TODO Auto-generated method stub
Sector2 Sector2Obj = (Sector2) getSupportFragmentManager().findFragmentById(R.id.pager);
Sector2Obj.setMessage(data);
Sector3 Sector3Obj = (Sector3) getSupportFragmentManager().findFragmentById(R.id.pager);
Sector3Obj.setMessage(data);
}
}
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
public class Sector1 extends Fragment
{
private Button btnAggiungi;
private EditText EtQta,EtName;
ListView userList;
ArrayList<User> userArray = new ArrayList<User>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.sector1, container, false);
btnAggiungi = (Button) rootView.findViewById(R.id.btn_aggiungi);
EtQta = (EditText) rootView.findViewById(R.id.Et_qta);
EtName = (EditText) rootView.findViewById(R.id.Et_name);
btnAggiungi.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
try {
String Qta = "Qtà: "+ String.valueOf(EtQta.getText());
String Prodotto = "prodotto: "+ String.valueOf(EtName.getText());
userArray.add(new User(Prodotto, Qta));
sharedData.onShareMyData(userArray);
} catch (Exception e) {
e.printStackTrace();
}
}
});
//return super.onCreateView(inflater, container, savedInstanceState);
return rootView;
}
OnShareMyDataListener sharedData;
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
sharedData = (OnShareMyDataListener) activity/*getActivity()*/;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString() + " must implement onShareMyData");
}
}
/**
* get datetime
* */
private String getDateTime() {
SimpleDateFormat dateFormat = new SimpleDateFormat(
"dd/MM/yyyy kk:MM", Locale.getDefault());
Date date = new Date();
return dateFormat.format(date);
}
private String getItemUserArray() {
String str=null;
for (int i = 0; i < userArray.size(); i++) {
str += userArray.get(i).toString();
}
return str;
}
}
public class Sector2 extends Fragment
{
private Button btnSendOrder,btnBrowseContact;
EditText nameField;
EditText emailField;
String subject = null;
TextView txt;
View rootView;
private Spinner mySpinnerEmail;
ArrayList<String> emailFornitore ;
ArrayList<String> aEmailList;
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.sector2, container, false);
init(rootView);
return rootView;
}
void init(View rootView){
}
/******************************************************************************/
void setMessage(ArrayList<User> data){
String str;
txt = (TextView)rootView.findViewById(R.id.Et_ordine);
str = "[" + data.get(0).getName() + "]\n";
subject = str;
for (int i = 1; i < data.size(); i++) {
str += data.get(i).getName() + "(" + data.get(i).getQta() + ")\n";
}
txt.setText(str);
}
}
public class Sector3 extends Fragment
{
Button buttonSend;
EditText textPhoneNo;
EditText textSMS;
TextView sms_count;
String subject = null;
TextView txt;
View rootView;
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.sector3, container, false);
init(rootView);
return rootView;
}
void init(View rootView){
}
void setMessage(ArrayList<User> data){
String str;
txt = (TextView)rootView.findViewById(R.id.editTextSMS);
str = "[" + data.get(0).getName() + "]\n";// + data.get(0).getQta() + "]\n";
subject = str;
for (int i = 1; i < data.size(); i++) {
str += data.get(i).getName() + "(" + data.get(i).getQta() + ")\n";
}
txt.setText(str);
}
}
public interface OnShareMyDataListener {
public void onShareMyData(ArrayList<User> data);
}
public class User {
String name;
String qta;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getQta() {
return qta;
}
public void setQta(String qta) {
this.qta = qta;
}
public User(String name, String qta) {
super();
this.name = name;
this.qta = qta;
}
}
答案 0 :(得分：0)
AppSectionPagerAdapter 扩展了什么？
如果您查看Android Doc，您会看到FragmentPagerAdapter 销毁您片段的查看层次。
因此，当你转到section3时，section1的视图层次结构被破坏，当你返回时，它完全被重新处理，但从头开始。
在您的代码中，主要问题是您要显示的数据未存储。请记住，在Activity [Fragment []]层次结构中，要点是活动，因此您必须将数据存储在Activity中，以便可以从任何地方访问它。
在您的活动中添加一个将更新的字段ArrayList<User> data：
@Override
public void onShareMyData(ArrayList<User> data) {
this.data = data;
}
在你的Sections的 onCreate（）：
中sharedData = (OnShareMyDataListener) activity;
sharedData.data