activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="change"
android:id="@+id/btn" />
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/btn2"
android:text="replace"
/>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/framelayout"
android:background="#fff000"
/>
</LinearLayout>fragment_blank1.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".BlankFragment1">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="@string/hello_blank_fragment" />
</FrameLayout>fragment_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="@+id/item_number"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/text_margin"
android:textAppearance="?attr/textAppearanceListItem" />
<TextView
android:id="@+id/content"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="@dimen/text_margin"
android:textAppearance="?attr/textAppearanceListItem" />
</LinearLayout>fragment_item_list.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/list"
android:name="com.example.fragmentmanagers.ItemFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginLeft="16dp"
android:layout_marginRight="16dp"
app:layoutManager="LinearLayoutManager"
tools:context=".ItemFragment"
tools:listitem="@layout/fragment_item" />BlankFragment1
package com.example.fragmentmanagers;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
/**
* A simple {@link Fragment} subclass.
* Use the {@link BlankFragment1#newInstance} factory method to
* create an instance of this fragment.
*/
public class BlankFragment1 extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
public BlankFragment1() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment BlankFragment1.
*/
// TODO: Rename and change types and number of parameters
public static BlankFragment1 newInstance(String param1, String param2) {
BlankFragment1 fragment = new BlankFragment1();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_blank1, container, false);
}
}ItemFragment
package com.example.fragmentmanagers;
import android.content.Context;
import android.os.Bundle;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.example.fragmentmanagers.placeholder.PlaceholderContent;
/**
* A fragment representing a list of Items.
*/
public class ItemFragment extends Fragment {
// TODO: Customize parameter argument names
private static final String ARG_COLUMN_COUNT = "column-count";
// TODO: Customize parameters
private int mColumnCount = 1;
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public ItemFragment() {
}
// TODO: Customize parameter initialization
@SuppressWarnings("unused")
public static ItemFragment newInstance(int columnCount) {
ItemFragment fragment = new ItemFragment();
Bundle args = new Bundle();
args.putInt(ARG_COLUMN_COUNT, columnCount);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mColumnCount = getArguments().getInt(ARG_COLUMN_COUNT);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_item_list, container, false);
// Set the adapter
if (view instanceof RecyclerView) {
Context context = view.getContext();
RecyclerView recyclerView = (RecyclerView) view;
if (mColumnCount <= 1) {
recyclerView.setLayoutManager(new LinearLayoutManager(context));
} else {
recyclerView.setLayoutManager(new GridLayoutManager(context, mColumnCount));
}
recyclerView.setAdapter(new MyItemRecyclerViewAdapter(PlaceholderContent.ITEMS));
}
return view;
}
}MainActivity
package com.example.fragmentmanagers;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn =findViewById(R.id.btn);
btn.setOnClickListener(this);
Button btn2= findViewById(R.id.btn2);
btn2.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.btn:
replaceFragment(new BlankFragment1());
break;
case R.id.btn2:
replaceFragment(new ItemFragment());
}
}
private void replaceFragment(Fragment fragment) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.framelayout,fragment);
fragmentTransaction.commit();
}
}MyItemRecyclerViewAdapter
package com.example.fragmentmanagers;
import androidx.recyclerview.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.example.fragmentmanagers.placeholder.PlaceholderContent.PlaceholderItem;
import com.example.fragmentmanagers.databinding.FragmentItemBinding;
import java.util.List;
/**
* {@link RecyclerView.Adapter} that can display a {@link PlaceholderItem}.
* TODO: Replace the implementation with code for your data type.
*/
public class MyItemRecyclerViewAdapter extends RecyclerView.Adapter<MyItemRecyclerViewAdapter.ViewHolder> {
private final List<PlaceholderItem> mValues;
public MyItemRecyclerViewAdapter(List<PlaceholderItem> items) {
mValues = items;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new ViewHolder(FragmentItemBinding.inflate(LayoutInflater.from(parent.getContext()), parent, false));
}
@Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.mItem = mValues.get(position);
holder.mIdView.setText(mValues.get(position).id);
holder.mContentView.setText(mValues.get(position).content);
}
@Override
public int getItemCount() {
return mValues.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public final TextView mIdView;
public final TextView mContentView;
public PlaceholderItem mItem;
public ViewHolder(FragmentItemBinding binding) {
super(binding.getRoot());
mIdView = binding.itemNumber;
mContentView = binding.content;
}
@Override
public String toString() {
return super.toString() + " '" + mContentView.getText() + "'";
}
}
}