java FragmentPagerAdapter总是从第一页开始
我有一个带有五个片段的片段寻呼机适配器,在第三个片段中,我想调用另一个活动,它将所选图片发送到容器。它工作正常,但每次从其他活动中选择图片时,寻呼机适配器都从片段活动中的第一个片段开始,而不是从第三个片段活动开始。我必须从其他活动强制寻呼机适配器,还是应该在片段活动中更改某些内容
代码:
片段活动:
package com.example.安卓.womb_the_game;
import 安卓.content.pm.ActivityInfo;
import 安卓.os.Bundle;
import 安卓.view.View;
import 安卓.view.Window;
import 安卓.view.WindowManager;
import 安卓x.fragment.app.FragmentActivity;
import 安卓x.fragment.app.FragmentPagerAdapter;
import 安卓x.viewpager.widget.ViewPager;
import com.google.安卓.material.floatingactionbutton.FloatingActionButton;
import com.google.安卓.material.snackbar.Snackbar;
import com.google.安卓.material.tabs.TabLayout;
public class Circulation extends FragmentActivity {
ViewPager vp;
public static FragmentPagerAdapter adapterViewPager;
@Override
protected void onCreate(Bundle onSavedInstanceState) {
super.onCreate(onSavedInstanceState);
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_circulation);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
vp = findViewById(R.id.view_pager);
adapterViewPager=new Adapter_Circulation(getSupportFragmentManager(), this);
vp.setAdapter(adapterViewPager);
TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.setupWithViewPager(vp);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
}
FragmentPagerAdapter:
package com.example.安卓.womb_the_game;
import 安卓x.fragment.app.Fragment;
import 安卓x.fragment.app.FragmentManager;
import 安卓x.fragment.app.FragmentPagerAdapter;
import 安卓.content.Context;
public class Adapter_Circulation extends FragmentPagerAdapter {
private static int NUM_ITEMS = 5;
Context context;
public Adapter_Circulation(FragmentManager fm, Context c) {
super(fm);
this.context = c;
}
@Override
public Fragment getItem(int position) {
switch (position)
{
case 0:
return Frg0.newInstance ();
case 1:
return Frg1.newInstance();
case 2:
return Frg2.newInstance();
case 3:
return Frg3.newInstance();
case 4:
return Frg4.newInstance();
}
return null; //does not happen
}
@Override
public int getCount() {
return NUM_ITEMS; //three fragments
}
@Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "RULES";
case 1:
return "EVENTS";
case 2:
return "PLAN";
case 3:
return "SHOOT";
case 4:
return "JUMP";
}
return null;
}
}
片段3:
package com.example.安卓.womb_the_game;
import 安卓.os.Bundle;
import 安卓x.annotation.Nullable;
import 安卓x.fragment.app.Fragment;
import 安卓x.fragment.app.FragmentManager;
import 安卓x.fragment.app.FragmentTransaction;
import 安卓.view.LayoutInflater;
import 安卓.view.View;
import 安卓.view.ViewGroup;
import 安卓.widget.ImageButton;
public class Frg3 extends Fragment{
private ImageButton shoot;
private ImageButton snipe;
private ImageButton aim;
public static Frg3 newInstance() {
Bundle args = new Bundle();
Frg3 fragment = new Frg3();
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable final Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View rootView = inflater.inflate(R.layout.fragment_frg3, container, false);
shoot = (ImageButton) rootView.findViewById(R.id.shoot);
snipe = (ImageButton) rootView.findViewById(R.id.snipe);
aim = (ImageButton) rootView.findViewById(R.id.aim);
final View.OnClickListener mListener = new View.OnClickListener() {
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.shoot:
FragmentManager FM0 = getFragmentManager();
FragmentTransaction FT0 = FM0.beginTransaction();
frg_shoot F10 = new frg_shoot();
FT0.add(R.id.fragment_container1, F10);
FT0.replace(R.id.fragment_container1, F10);
FT0.commit();
break;
case R.id.snipe:
FragmentManager FM = getFragmentManager();
FragmentTransaction FT = FM.beginTransaction();
frg_snipe F1 = new frg_snipe();
FT.add(R.id.fragment_container1, F1);
FT.replace(R.id.fragment_container1, F1);
FT.commit();
break;
case R.id.aim:
FragmentManager FM1 = getFragmentManager();
FragmentTransaction FT1 = FM1.beginTransaction();
frg_aim F11 = new frg_aim();
FT1.add(R.id.fragment_container1, F11);
FT1.replace(R.id.fragment_container1, F11);
FT1.commit();
break;
}
}
};
rootView.findViewById(R.id.shoot).setOnClickListener(mListener);
rootView.findViewById(R.id.snipe).setOnClickListener(mListener);
rootView.findViewById(R.id.aim).setOnClickListener(mListener);
return rootView;
}
}
其他活动:
package com.example.安卓.womb_the_game;
import 安卓x.fragment.app.FragmentActivity;
import 安卓.content.Intent;
import 安卓.content.pm.ActivityInfo;
import 安卓.os.Bundle;
import 安卓.view.View;
import 安卓.view.Window;
import 安卓.view.WindowManager;
import 安卓.widget.ImageButton;
import 安卓.widget.ImageView;
public class choose_dice_column extends FragmentActivity {
private ImageButton b1;
private ImageView im1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_choose_dice_column);
this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
b1 = (ImageButton) findViewById(R.id.b1);
im1 = findViewById(R.id.im1);
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent i = new Intent(choose_dice_column.this, Circulation.class);
i.putExtra("resid1",R.drawable.n1);
startActivity(i);
}
});
}
}
# 1 楼答案
问题是,每当你回到你的活动中,你都在创建一个新的适配器。因此,将以下内容添加到
Circulation
-活动中,以保持适配器的状态: