android - 如何在MainActivity中滑动viewpager时更新viewpager fragment 内容

Question

当 viewpager 在 MainActivity 中滑动时，我正在尝试更新 viewpager fregment。

菜单 Activity :-

package jbit.kanha;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.koushikdutta.async.future.FutureCallback;
import com.koushikdutta.ion.Ion;
import com.romainpiel.shimmer.Shimmer;
import com.romainpiel.shimmer.ShimmerTextView;

import org.json.JSONArray;
import org.json.JSONObject;

import jbit.kanha.AllAdepters.SideMenuAdapter;
import jbit.kanha.InternetConection.CheckInternetConection;
import jbit.kanha.InternetConection.ConnectionDetector;
import jbit.kanha.InternetConection.InternetDialoge;
import jbit.kanha.ProgressDialog.MyProgressDialog;
import jbit.kanha.SideMenuClasses.MyProfile;
import jbit.kanha.db.Database;

public class MenuActivity extends FragmentActivity  implements View.OnClickListener{

    public static ResideMenu resideMenu;
    private MenuActivity mContext;
    private ResideMenuItem itemHome;
    private ResideMenuItem itemProfile;
    private ResideMenuItem itemCalendar;
    private ResideMenuItem itemSettings;
    SharedPreferences loginPreferences;
    private SharedPreferences pref;
    ImageView profile_image;
    public static TextView title_bar_right_menu,txt_total_rate;
    Database database;
    JSONArray categoryItem;
  //  private PagerSlidingTabStrip tabLayout;
    private TabLayout tabLayout;
    ViewPager pager;
    private ConnectionDetector connectionDetector;
    private MyProgressDialog dialog;
    ViewPagerAdapter adapter;

    OneFregment fregment;
 //   private int currentColor = Color.parseColor("#1D569B");
  //  PagerSlidingTabStrip tabStrip;
    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mContext = this;
        database = new Database(MenuActivity.this);
        tabLayout= (TabLayout)findViewById(R.id.tabs);

        pager = (ViewPager)findViewById(R.id.pager);
        loginPreferences = getSharedPreferences("loginPrefs", Context.MODE_PRIVATE);
        connectionDetector = new ConnectionDetector(mContext);
        dialog = new MyProgressDialog(mContext);
        adapter = new ViewPagerAdapter(getSupportFragmentManager());
        if (connectionDetector.isConnectingToInternet()){
            getCategoryName();
        }else{
            Toast.makeText(mContext, "No Internet Connection", Toast.LENGTH_SHORT).show();
        }
        title_bar_right_menu = (TextView) findViewById(R.id.title_bar_right_menu);
        txt_total_rate = (TextView) findViewById(R.id.txt_total_rate);

        pref = getApplicationContext().getSharedPreferences("loginPrefs", MODE_PRIVATE);
        Cursor cursor1 =  database.getData("SELECT * FROM cart");
        int count = cursor1.getCount();
        cursor1.close();
        title_bar_right_menu.setText(count+"");

        setUpMenu();


        pager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                getCategoryDataRefresh(position);

            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

    }


    private void getCategoryData(final int postion){
        Ion.with(mContext)
                .load(getResources().getString(R.string.api_main_url) + "categoryoriginal.php")
                .setTimeout(30*1000)
                .setBodyParameter("outlet_id",loginPreferences.getString("outlet_id",""))
                .setBodyParameter("catid",String.valueOf(postion+1))
                .asString().setCallback(new FutureCallback<String>() {
            @Override
            public void onCompleted(Exception e, String result) {
                 dialog.hide();
                if (e != null) {
                    e.printStackTrace();
                    DialogsClassTwoData(mContext, "Connection Timed Out!", "Message...",postion).show();
                }
                if (result != null) {
                    try {
                        Log.d("name",result);
                        JSONObject mainJson = new JSONObject(result);
                        String status = mainJson.getString("status");
                        if(status.equals("Success")){
                            JSONArray jsonArray = mainJson.getJSONArray("data");
                            setUpViewPager(pager,categoryItem,jsonArray);
                        }
                    }catch (Exception ex) {
                        ex.printStackTrace();
                        Log.d("exaption", ex.toString());

                    }
                } else {
                    Log.d("exaption", e.toString());
                }
            }
        });

    }
    private void getCategoryDataRefresh(final int postion){
        dialog.show();
        Ion.with(mContext)
                .load(getResources().getString(R.string.api_main_url) + "categoryoriginal.php")
                .setTimeout(30*1000)
                .setBodyParameter("outlet_id",loginPreferences.getString("outlet_id",""))
                .setBodyParameter("catid",String.valueOf(postion+1))
                .asString().setCallback(new FutureCallback<String>() {
            @Override
            public void onCompleted(Exception e, String result) {
                dialog.hide();
                if (e != null) {
                    e.printStackTrace();
                    DialogsClassTwoData(mContext, "Connection Timed Out!", "Message...",postion).show();
                }
                if (result != null) {
                    try {
                        Log.d("name",result);
                        JSONObject mainJson = new JSONObject(result);
                        String status = mainJson.getString("status");
                        if(status.equals("Success")){

                            Fragment frg = null;
                            frg = new OneFregment(mainJson.getJSONArray("data"));
                            final FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
                            ft.detach(frg);
                            ft.attach(frg);
                            ft.commit();
                        }
                    }catch (Exception ex) {
                        ex.printStackTrace();
                        Log.d("exaption", ex.toString());

                    }
                } else {
                    Log.d("exaption", e.toString());
                }
            }
        });

    }

    private void getCategoryName(){
        dialog.show();
        Ion.with(mContext)
                .load(getResources().getString(R.string.api_main_url) + "categoryname.php")
                .setTimeout(30*1000)
                .asString().setCallback(new FutureCallback<String>() {
            @Override
            public void onCompleted(Exception e, String result) {
              //  dialog.hide();
                if (e != null) {
                    e.printStackTrace();
                    DialogsClassTwo(mContext, "Connection Timed Out!", "Message...").show();
                }
                if (result != null) {
                    try {
                        Log.d("name",result);
                        JSONObject mainJson = new JSONObject(result);
                        String status = mainJson.getString("status");
                        if(status.equals("Success")){
                            JSONObject jsonObject = mainJson.getJSONObject("data");
                            categoryItem = jsonObject.getJSONArray("items");

//                            setUpViewPager(pager,jsonObject.getJSONArray("items"));
                            Log.d("json",jsonObject+"");

                            getCategoryData(0);
                            //data = jsonObject.getJSONArray("items");
                           /* for(int i=0;i<data.length();i++){
                                JSONObject jsonObject1 = data.getJSONObject(i);
                                bigImage.add(jsonObject1.getString("bigimage"));
                            }
                            pager.setAdapter(new CustomPagerAdapter(getActivity(),data));
                            final int pageMargin = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 4, getResources()
                                    .getDisplayMetrics());
                            pager.setPageMargin(pageMargin);
                            tabs.setViewPager(pager);
                            changeColor(currentColor);*/

                        }
                    }catch (Exception ex) {
                        ex.printStackTrace();
                        Log.d("exaption", ex.toString());

                    }
                } else {
                    Log.d("exaption", e.toString());
                }
            }
        });
    }
    private void setUpViewPager(ViewPager pager, JSONArray jsonArray,JSONArray products){
        try {
           // ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
            for(int i=0;i<jsonArray.length();i++){
                JSONObject jsonObject = jsonArray.getJSONObject(i);
                adapter.addFrag(new OneFregment(products),jsonObject.getString("categoryname"));
            }
            pager.setAdapter(adapter);
            tabLayout.setupWithViewPager(pager);
           // tabLayout.tabSelectedTextColor
           // getCategoryData();
        }
        catch (Exception e) {
            Log.e("error", e.getMessage());
        }
    }

    public AlertDialog.Builder DialogsClassTwo(Context cxt, final String message, String title){
        return  new AlertDialog.Builder(cxt).setTitle(title).setMessage(message).setPositiveButton("Try Again", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialogs, int which) {
                // here you can add functions
                if (CheckInternetConection.isInternetConnection(mContext.getApplicationContext())){
                      getCategoryName();
                   // getCategoryData();
                }else{
                    InternetDialoge.showDialogFinishActivity(
                            "Internet Connection Failed!", "connection error", mContext);
                }
            }
        });
    }
    public AlertDialog.Builder DialogsClassTwoData(Context cxt, final String message, String title, final int postion){
        return  new AlertDialog.Builder(cxt).setTitle(title).setMessage(message).setPositiveButton("Try Again", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialogs, int which) {
                // here you can add functions
                if (CheckInternetConection.isInternetConnection(mContext.getApplicationContext())){
                    //getCategoryName();
                     getCategoryData(postion);
                }else{
                    InternetDialoge.showDialogFinishActivity(
                            "Internet Connection Failed!", "connection error", mContext);
                }
            }
        });
    }

    private void setUpMenu() {
        resideMenu = new ResideMenu(MenuActivity.this, R.layout.side_menu, R.layout.home);
        //resideMenu.setBackground(Color.parseColor("#FAA514"));//FAA514
        resideMenu.setBackground(R.drawable.slider_background);
        resideMenu.attachToActivity(MenuActivity.this);
        resideMenu.setScaleValue(0.5f);
        View leftMenu = resideMenu.getLeftMenuView();
        Shimmer shimmer = new Shimmer();//#faebd7
        shimmer.setDuration(3000)
                .setStartDelay(500)
                .setDirection(Shimmer.ANIMATION_DIRECTION_LTR);
        ShimmerTextView powered = (ShimmerTextView)leftMenu.findViewById(R.id.powered);
        ListView list = (ListView) leftMenu.findViewById(R.id.list1);
        list.setAdapter(new SideMenuAdapter(MenuActivity.this));
        profile_image = (ImageView) leftMenu.findViewById(R.id.profile_image);
        TextView title1 = (TextView) leftMenu.findViewById(R.id.title1);
        TextView loction1 = (TextView) leftMenu.findViewById(R.id.loction1);
        ImageView location_icon =(ImageView) leftMenu.findViewById(R.id.location_icon);
        RelativeLayout ll_checkout = (RelativeLayout) findViewById(R.id.ll_checkout);
        //loginPreferences = getSharedPreferences("loginPrefs", Context.MODE_PRIVATE);
        title1.setText(loginPreferences.getString("fullname",""));
        loction1.setText(loginPreferences.getString("address",""));
        //   if(!loginPreferences.getString("profileimage","").equals("")){
       /*     Picasso.with(MenuActivity.this)
                    .load(loginPreferences.getString("profileimage",""))
                    .error(R.drawable.images)
                    .placeholder(R.drawable.progress_animation)
                    .into(profile_image);*/
        //  File file = new File("/main_json/main_json/com.example.w.lazymojo/app_imageDir/profile.jpg");

        shimmer.start(powered);
        if(pref.getString("User_id", "").equals("")){
            profile_image.setImageResource(R.drawable.images);
            location_icon.setVisibility(View.INVISIBLE);
        }
        else {
            Bitmap bitmap1 = BitmapFactory.decodeFile("/data/data/jbit.kanha/app_imageDir/profile.jpg");
            if(bitmap1!=null){
                Log.d("MenuActivity:-","image not null");
                profile_image.setImageBitmap(bitmap1);
                //  Picasso.with(MenuActivity.this).load(file).resize(dpToPx(96),dpToPx(96)).centerCrop().into(profile_image);
            }
            else {
                Log.d("MenuActivity:-","image is null");
                profile_image.setImageResource(R.drawable.images);
            }
        }

        profile_image.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(pref.getString("User_id", "").equals("")){
                    profile_image.setImageResource(R.drawable.images);
                    new AlertDialog.Builder(MenuActivity.this).setTitle("Login").setMessage("You have to login first").setPositiveButton("Login", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Intent in = new Intent(MenuActivity.this,LoginActivity.class);
                            startActivity(in);
                        }
                    }).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    }).show();
                }
                else {
                    Intent i = new Intent(MenuActivity.this, MyProfile.class);
                    startActivity(i);
                }
            }
        });

        //     }
        ll_checkout.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(!pref.getString("User_id", "").equals("")){
                    Intent i = new Intent(MenuActivity.this,MyCart.class);
                    startActivity(i);
                    finish();
                }
                else
                {
                    new AlertDialog.Builder(MenuActivity.this).setTitle("Login").setMessage("You must login first").setPositiveButton("Login", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Intent intent = new Intent(MenuActivity.this,LoginActivity.class);
                            startActivity(intent);
                        }
                    }).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    }).show();
                }
            }
        });
        resideMenu.setSwipeDirectionDisable(ResideMenu.DIRECTION_RIGHT);
        resideMenu.setSwipeDirectionDisable(ResideMenu.DIRECTION_LEFT);
        findViewById(R.id.title_bar_left_menu).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                resideMenu.openMenu(ResideMenu.DIRECTION_LEFT);
            }
        });
        findViewById(R.id.cart_img).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(!pref.getString("User_id", "").equals("")){
                    Intent i = new Intent(MenuActivity.this,MyCart.class);
                    startActivity(i);
                    finish();
                }
                else
                {
                    new AlertDialog.Builder(MenuActivity.this).setTitle("Login").setMessage("You must login first").setPositiveButton("Login", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            Intent intent = new Intent(MenuActivity.this,LoginActivity.class);
                            startActivity(intent);
                        }
                    }).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            dialog.dismiss();
                        }
                    }).show();
                }
                //  resideMenu.openMenu(ResideMenu.DIRECTION_RIGHT);
            }
        });
    }


    @Override
    public void onClick(View view) {
        resideMenu.closeMenu();
    }

    private ResideMenu.OnMenuListener menuListener = new ResideMenu.OnMenuListener() {
        @Override
        public void openMenu() {
            // Toast.makeText(mContext, "Menu is opened!", Toast.LENGTH_SHORT).show();
        }

        @Override
        public void closeMenu() {
            //Toast.makeText(mContext, "Menu is closed!", Toast.LENGTH_SHORT).show();
        }
    };

    // What good method is to access resideMenu？
    public ResideMenu getResideMenu(){
        return resideMenu;
    }


    @Override
    protected void onResume() {
        super.onResume();
    }

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        finish();
        moveTaskToBack(true);
    }
}

ViewPagerAdapter.java:

class  ViewPagerAdapter extends FragmentPagerAdapter {

    private final List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();

    public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
    }

    @Override
    public Fragment getItem(int position) {
            return mFragmentList.get(position);
            }

    @Override
    public int getCount() {
            return mFragmentList.size();
            }

    public void addFrag(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
            }

    @Override
    public int getItemPosition(Object object) {

        return POSITION_NONE;
    }

    @Override
    public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
            }
}

OneFregement:-

public class OneFregment extends Fragment {


     JSONArray jsonArray;
    ListView listView;
     HomeLiatAdapter adapter;

    public OneFregment() {
        // Required empty public constructor
    }

    @SuppressLint("ValidFragment")
    public OneFregment(JSONArray jsonArray){
        this.jsonArray = jsonArray;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v =  inflater.inflate(R.layout.home_child_layout, container, false);

        listView = (ListView) v.findViewById(R.id.list);

        try {
            JSONObject obj = jsonArray.getJSONObject(0);
            adapter = new HomeLiatAdapter(getContext(),obj.getJSONArray("items"),obj.getString("bigimage"));
            listView.setAdapter(adapter);

        }catch (Exception e){
            e.printStackTrace();
        }


        return v;
    }

  /*  public void update(){
        try {
            JSONObject obj = jsonArray.getJSONObject(0);
            adapter = new HomeLiatAdapter(getContext(),obj.getJSONArray("items"),obj.getString("bigimage"));
            listView.setAdapter(adapter);

        }catch (Exception e){
            e.printStackTrace();
        }
    }*/
}

我正在这样做，但 fregment 显示以前的数据。我也尝试在 fregment 类中创建更新方法，但一切都在等待。

我是 Android 开发的新手，请帮助我。提前致谢。

Answer 1

您必须编写自定义接口(interface)并在每个 fragment 中实现。在 onpagechangelistener 上，您必须调用这些方法。

check this更多解释。甚至我必须为我的项目实现相同的操作以使 fragment 更新，因为正常的 fragment 生命周期不会按您想要的那样工作。由于在您滑动浏览时查看寻呼机添加和保留 fragment 。