我有一个问题，似乎我无法通过搜索来解决它。 我注意到还有其他解决方案但是当我通过事务传递一个bundle时程序停止工作，所有其他解决方案到目前为止都失败了。
请注意，这是一个标签式应用程序。
我想做什么。
代码在
之下MainActivity.java（这里没什么特别的）
import android.support.design.widget.TabLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
/**
* The {@link android.support.v4.view.PagerAdapter} that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive, it
* may be best to switch to a
* {@link android.support.v4.app.FragmentStatePagerAdapter}.
*/
private SectionsPagerAdapter mSectionsPagerAdapter;
/**
* The {@link ViewPager} that will host the section contents.
*/
private ViewPager mViewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mSectionsPagerAdapter);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
mViewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(mViewPager));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
public PlaceholderFragment() {
}
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static PlaceholderFragment newInstance(int sectionNumber) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle args = new Bundle();
args.putInt(ARG_SECTION_NUMBER, sectionNumber);
fragment.setArguments(args);
return fragment;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
TextView textView = (TextView) rootView.findViewById(R.id.section_label);
textView.setText(getString(R.string.section_format, getArguments().getInt(ARG_SECTION_NUMBER)));
return rootView;
}
}
/**
* A {@link FragmentPagerAdapter} that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
public SectionsPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
switch (position) {
case 0:
return MainActivity.PlaceholderFragment.newInstance(position + 1);
case 1:
return exercises.newInstance();
case 2:
return MainActivity.PlaceholderFragment.newInstance(position + 1);
case 3:
return MainActivity.PlaceholderFragment.newInstance(position + 1);
case 4:
return MainActivity.PlaceholderFragment.newInstance(position + 1);
//case two for later
/*case 2:
return AnotherFragment.newInstance();*/
}
return null;
}
@Override
public int getCount() {
// Show 5 total pages.
return 5;
}
}
}
exerciseList.Java（可扩展的listView类，不包括自定义适配器）
package com.example.rowan.assignment1;
/* Intent activity created for used to select exercise from expandable List menu to save space on other App pages
*/
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.ExpandableListView;
import java.io.FileOutputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class exerciseList extends AppCompatActivity {
ExpandableListAdapter listAdapter;
ExpandableListView expListView;
List<String> listDataHeader;
HashMap<String, List<String>> listDataChild;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_exercise_list);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//get the listView
expListView = (ExpandableListView) findViewById(R.id.lvExp);
//set the data
prepareListData();
listAdapter = new ExpandableListAdapter(this, listDataHeader, listDataChild);
// setting list adapter
expListView.setAdapter(listAdapter);
expListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {
String muscle = listDataHeader.get(groupPosition);
String exercise = listDataChild.get( listDataHeader.get(groupPosition)).get(
childPosition);
//On ListView child click, return to fragment with data
//Previous attempts
/*Intent intent = new Intent(getApplicationContext(),
MainActivity.class);
Bundle bundle = new Bundle();
bundle.putString("muscle", muscle);
bundle.putString("exercise", exercise);
startActivity(intent);
//another attempt
Bundle args = new Bundle();
args.putString("muscle", muscle);
args.putString("exercise", exercise);
exercises fragment = new exercises();
fragment.setArguments(args);
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.tabItem2, fragment);
transaction.commit();
//yet another
exercises fragment = (exercises) getSupportFragmentManager().findFragmentById(R.id.tabItem2);
fragment.setData(muscle,exercise);
finish();
//4th attempt
try {
FileOutputStream out;
store f = new store(muscle, exercise);
out=openFileOutput("exfile", MODE_PRIVATE);
ObjectOutputStream oout = new ObjectOutputStream(out);
oout.writeObject(f);
oout.close();
}
catch (Exception ex) {
ex.printStackTrace();
}
finish();
*/
return false;
}
});
}
private void prepareListData(){
listDataHeader = new ArrayList<String>();
listDataChild = new HashMap<String, List<String>>();
//adding parent data
listDataHeader.add("Chest");
listDataHeader.add("Back");
listDataHeader.add("Shoulders");
listDataHeader.add("Quadriceps");
listDataHeader.add("Hamstring");
listDataHeader.add("Biceps");
listDataHeader.add("Triceps");
List<String> chestEx = new ArrayList<String>();
chestEx.add("Push Ups");
chestEx.add("Bench Press");
chestEx.add("Cable Crossover");
chestEx.add("Pec Deck");
listDataChild.put(listDataHeader.get(0), chestEx);
List<String> backEx = new ArrayList<String>();
backEx.add("Pull Ups");
backEx.add("Chin Ups");
backEx.add("Lat Pull-downs");
backEx.add("Dumbbell Row");
backEx.add("Dumbbell Shrugs");
listDataChild.put(listDataHeader.get(1), backEx);
List<String> shoulderEx = new ArrayList<String>();
shoulderEx.add("Overhead Dumbbell Press");
shoulderEx.add("Overhead Machine Press");
shoulderEx.add("Arnold Press");
shoulderEx.add("Upright Rows");
shoulderEx.add("Rear Deltoid Rows/Raises/Flyes");
listDataChild.put(listDataHeader.get(2), shoulderEx);
List<String> quadricepsEx = new ArrayList<String>();
quadricepsEx.add("Squats");
quadricepsEx.add("Lunges");
quadricepsEx.add("Step-ups");
quadricepsEx.add("Leg Press");
quadricepsEx.add("Leg Extensions");
listDataChild.put(listDataHeader.get(3), shoulderEx);
List<String> hamstringEx = new ArrayList<String>();
hamstringEx.add("Deadlifts");
hamstringEx.add("Hyperextensions");
hamstringEx.add("Glute/Ham raises");
hamstringEx.add("Leg Curls");
hamstringEx.add("Cable Pull-Throughs");
listDataChild.put(listDataHeader.get(4), hamstringEx);
List<String> bicepEx = new ArrayList<String>();
bicepEx.add("Cable Curls");
bicepEx.add("Machine Curls");
bicepEx.add("Dumbbell Curls");
bicepEx.add("Barbell Curls");
listDataChild.put(listDataHeader.get(5), bicepEx);
List<String> tricepEx = new ArrayList<String>();
tricepEx.add("Dips");
tricepEx.add("Bench Press");
tricepEx.add("Close Grip Push-Ups");
tricepEx.add("Tricep Extensions");
tricepEx.add("Skull Crushers");
listDataChild.put(listDataHeader.get(6), tricepEx);
}
}
exercise.Java（Fragment class [Tabbed app]）
package com.example.rowan.assignment1;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import java.io.FileInputStream;
import java.io.ObjectInputStream;
/**
* A simple {@link Fragment} subclass.
*/
public class exercises extends Fragment {
Button exButton;
Button update;
String muscle, exercise;
public exercises() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_exercises, container, false);
/*muscle = getArguments().getString("muscle");
exercise = getArguments().getString("exercise");*/
// Insert onCreate code here
exButton = (Button) view.findViewById(R.id.exbutton);
/*if (muscle == "Chest") {
exButton.setBackgroundResource(R.mipmap.chest);
exButton.setText(exercise);
}*/
exButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
// on click move to intent with expandable listView for selection
Intent intent = new Intent(getActivity(), exerciseList.class);
startActivity(intent);
}
});
return view;
}
public static exercises newInstance() {
exercises fragment = new
exercises();
return fragment;
}
//Function from failed attempt
/*public void setData(String m, String e){
muscle = m;
exercise = e;
}*/
}
非常感谢任何帮助或指示
答案 0 :(得分：0)
我已经解决了问题，Albiet可能有更好的解决方案。 我已经将一个Intent从exerciseList.Java传递给了MainActivity.Java
Intent intent = new Intent(getApplicationContext(),
MainActivity.class);
//Data
intent.putExtra("muscle", muscle);
intent.putExtra("exercise", exercise);
intent.putExtra("frag", 1);
startActivity(intent);
然后我将数据从MainActivity.Java传递给exercise.Java（The Fragment）
Intent intent = getIntent();
int frag = intent.getIntExtra("frag",0);
if (frag == 1){
muscle = intent.getStringExtra("muscle");
exercise = intent.getStringExtra("exercise");
//exercises is menu item 1 (mainActivity is 0)
mViewPager.setCurrentItem(frag);
}
//Another section of code
public String getMuscle(){
return muscle;
}
public String getExercise(){
return exercise;
}
最后我访问了exercise.Java中的数据
MainActivity activity = (MainActivity) getActivity();
muscle = activity.getMuscle();
exercise = activity.getExercise();