I tried to create a ViewPager in Android Studio.
I get the error:
PagerAdapter() cannot be applied to android.app FragmentManager
at the line super(fm);
Here is my code for the adapter. Do I need to change anything?
package com.example.admin.usthweather;
import android.app.Fragment;
import android.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.view.View;
/**
* Created by Admin on 11/15/2017.
*/
public class HomeFragmentAdapter extends PagerAdapter {
private final int PAGE_COUNT = 3;
private String titles[] = new String[] {"Hanoi","Paris", "Saigon"};
public HomeFragmentAdapter(FragmentManager fm){
super(fm);
}
#Override
public int getCount() {
return PAGE_COUNT;
}
// Override
public Fragment getItem(int page) {
// returns an instance of Fragment corresponding to the specified page
Fragment frag=null;
switch (page){
case 0:
frag=new Hanoi();
break;
case 1:
frag=new Paris();
break;
case 2:
frag=new Saigon();
break;
}
return frag;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return false;
}
}
There is no constructor in PagerAdapter with FragmentManager as parameter. You're code is similar for FragmentPagerAdapter or FragmentStatePagerAdapter so you can use one of them. It will be something like this:
public class HomeFragmentAdapter extends FragmentStatePagerAdapter {
private final int PAGE_COUNT = 3;
private String titles[] = new String[] {"Hanoi","Paris", "Saigon"};
public HomeFragmentAdapter(FragmentManager fm){
super(fm);
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public Fragment getItem(int page) {
Fragment frag=null;
switch (page){
case 0:
frag=new Hanoi();
break;
case 1:
frag=new Paris();
break;
case 2:
frag=new Saigon();
break;
}
return frag;
}
}
Please remember to use the correct import file for Fragment and FragmentManager from Support library:
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
fm in super(fm); is wrong. Therefore none of this is necessary:
public HomeFragmentAdapter(FragmentManager fm){
super(fm);
}
However, I suspect that you did not want to subclass PagerAdapter, but either or FragmentStatePagerAdapter. As the docs say:
Base class providing the adapter to populate pages inside of a ViewPager. You will most likely want to use a more specific implementation of this, such as FragmentPagerAdapter or FragmentStatePagerAdapter.
Instead of providing a View recycling mechanism directly ViewPager uses callbacks to indicate the steps taken during an update.
Related
My application is working fine when I use getChildFragmentManager() but unfortunately, it will only work with API 17 and above. Now when I switch it over to getFragmentManager(), everything works fine except for one thing. Whenever I load my tablayout in horizontal view, both pages are empty and swiping is sluggish. Vertically it is fine and they won't be empty if I first load them vertically and then switch to horizontally, because I'm using a saved instance. I have no idea what is causing this. All I know is that as soon as I switch the code above around, it happens. Let me know what is required to find the issue and I will gladly post it. I am using the support-v13 library's FragmentPagerAdapter. I am doing this so I don't have to use support-v4's way of creating fragments. I do import the ViewPager from v4 in my tablayout fragment.
Edit:
Okay when the tablayout is created for the first time, it works fine. When called again it will be blank and sluggish. It had nothing to do with orientation.
Edit:
Tablayout code Keep in mind that this code is functional. But when I change getChildFragmentManager() to getFragmentManager() it gets sluggish and only works on first oncreate:
import android.app.Fragment;
import android.app.FragmentManager;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.support.v13.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class TabFragment extends Fragment {
public static TabLayout tabLayout;
public static ViewPager viewPager;
public static int int_items = 2;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View x = inflater.inflate(R.layout.tab_layout, null);
tabLayout = (TabLayout) x.findViewById(R.id.tabs);
viewPager = (ViewPager) x.findViewById(R.id.viewpager);
viewPager.setAdapter(new MyAdapter(getChildFragmentManager()));
tabLayout.post(new Runnable() {
#Override
public void run() {
tabLayout.setupWithViewPager(viewPager);
}
});
return x;
}
class MyAdapter extends FragmentPagerAdapter {
public MyAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new FragmentOne();
case 1:
return new FragmentTwo();
}
return null;
}
#Override
public int getCount() {
return int_items;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return "TAB1";
case 1:
return "TAB2";
}
return null;
}
}
}
So I want to make an app that has multiple tabs that I can slide between.
I choose the Tabbed Acitivity with Action Bar Tabs (with ViewPager) navigation tabs.
I am trying to make each tab correspond with a fragment. So I can change the lay-out of each fragment etc.
A part of my fragment code is:
public class Page1Fragment extends Fragment {
private OnFragmentInteractionListener mListener;
public Page1Fragment() {
// Required empty public constructor
}
*This is not the complete code
In my SeciontsPagerAdapter, this is my getItem method.
#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).
// return MainActivity.PlaceholderFragment.newInstance(position + 1);
switch(position){
case 0:
return new Page1Fragment();
case 1:
return new Page2Fragment();
case 2:
return new Page3Fragment();
case 3:
return new Page4Fragment();
}
return null;
}
But I get an error? It says Page1Fragment can't be converted to a Fragment?
But I let Page1Fragment extends from Fragment?
Does anyone have any idea why this doesn't work?
Try this:
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class TabsPagerAdapter extends FragmentPagerAdapter {
public TabsPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
return new GamesFragment1();//.newInstance(0);
case 1:
return new GamesFragment2();//.newInstance(1);
case 2:
return new GamesFragment3();//.newInstance(2);
}
return null;
}
#Override
public int getCount() {
// get item count - equal to number of tabs
return 3;
}
}
Page1Fragment:
import android.support.v4.app.Fragment;
import android.support.v4.view.ViewPager.PageTransformer;
There are two fragment classes either you have to use support library class or app.fragment class. don't mix it up
You need to import below
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
Did you add this ?
import android.support.v4.app.FragmentStatePagerAdapter;
SetFragmentStatePagerAdapter instead of FragmentPagerAdapter
I'm trying to make an application that has two fragments that are both different in function and you can swipe right to go between them. I've looked into how to do this, but no solution seems to work.
Tabs and Swipe - editing the getItem to display 3 different fragments
Im trying to implement a getitem similar to this, but as you can see in this code:
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* Created by cwallace on 11/10/14.
*/
//Implement PagerAdapter Class to handle individual page creation
class MyPagesAdapter extends FragmentPagerAdapter {
public MyPagesAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return 2;
}
#Override
public Fragment getItem(int position) {
Fragment fragment = new InitialFragment();
return fragment;
}
}
I want to return a different type of fragment than the function wants, and I can't cast my Initial Fragment to the Fragment class. Am I even attempting to do this the correct way?
Let's point out some things.
can't cast my Initial Fragment, make sure that your initialFragment class extends the Fragment.
As #hitch.united suggest, in getItem() of adapter , you can return the fragment by the id in a if-else. But remember that: You should not use this function to retrieve the fragment!
I can suggest you by using the ViewPager for swipe operation.
Try this way:
class MyPagesAdapter extends FragmentPagerAdapter {
public MyPagesAdapter(FragmentManager fm) {
super(fm);
}
#Override
public int getCount() {
return 2;
}
#Override
public Fragment getItem(int position) {
Fragment fragment = null;
switch(position) {
case 0:
fragment = new InitialFragment();
break;
case 1:
fragment = new YourSecondFragment();
break;
}
return fragment;
}
}
In my MainActivity i have this code:
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
public class MainActivity extends FragmentActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myViewPager.setCurrentItem(1);
ViewPager pager = (ViewPager) findViewById(R.id.viewPager);
pager.setAdapter(new MyPagerAdapter(getSupportFragmentManager()));
}
private class MyPagerAdapter extends FragmentPagerAdapter {
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int pos) {
switch(pos) {
case 2: return FirstFragment.newInstance("FirstFragment, Instance 1");
case 1: return SecondFragment.newInstance("SecondFragment, Instance 1");
case 0: return ThirdFragment.newInstance("ThirdFragment, Instance 1");
default: return ThirdFragment.newInstance("ThirdFragment, Default");
}
}
#Override
public int getCount() {
return 3;
}
}
}
The fragments are working fine and when i run MainActivity i want to open the SecondFragment first, so i tried using:
myViewPager.setCurrentItem(1);
But then i get the error "myViewPager cannot be resolved", i have tried updating SDK and adding support library, but nothing seems to help, any idea how to fix it?
You have not declared myViewPager and you also need to initialize it before myViewPager.setCurrentItem(1);.
You probably meant pager.setCurrentItem(1);
I'm trying to make a slidescreen with viewpager and fragments so that I can load different layouts per fragment and give each page different functionality.
I followed a tutorial to accomplish this.
The error I'm getting when hovering over public Fragment getItem(int arg0): The return type is incompatible with FragmentPagerAdapter.getItem(int)
and error #2: The constructor FragmentPagerAdapter(FragmentManager) is undefined
--> getting this one when hovering super(fm);
package com.example.spui;
import android.os.Bundle;
import android.app.Fragment;
import android.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class MyFragmentPagerAdapter extends FragmentPagerAdapter{
final int PAGE_COUNT = 5;
/** Constructor of the class */
public MyFragmentPagerAdapter(FragmentManager fm) {
super(fm);
}
/** This method will be invoked when a page is requested to create */
#Override
public Fragment getItem(int arg0) {
MyFragment myFragment = new MyFragment();
Bundle data = new Bundle();
data.putInt("current_page", arg0+1);
myFragment.setArguments(data);
return myFragment;
}
/** Returns the number of pages */
#Override
public int getCount() {
return PAGE_COUNT;
}
}
You are using the wrong FragmentManager import. Use android.support.v4.app.FragmentManager instead.
Same problem with Fragment - use android.support.v4.app.Fragment
Note: if you are building an API11+ only application and want to use the native Fragments, then you should instead change your FragmentPagerAdapter import to android.support.v13.app.FragmentPagerAdapter.