1. Function Description#
Edit Function
Delete Function
View Detail Page
2. Core Code#
XML Part#
item.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"
android:id="@+id/linearLayout_item1"
android:layout_width="match_parent"
android:layout_height="80dp"
android:background="@drawable/underline_list"
android:orientation="horizontal">
<ImageView
android:id="@+id/imageView_item1"
android:layout_width="72dp"
android:layout_height="53dp"
android:layout_gravity="center"
app:srcCompat="@drawable/ic___wx_this" />
<TextView
android:id="@+id/textView_item1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:text="Number"
android:textSize="16dp" />
<TextView
android:id="@+id/textView_item2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:text="Content"
android:textSize="16dp" />
</LinearLayout>
tab02.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:background="@color/hui"
android:layout_height="match_parent"
android:orientation="horizontal">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recyclerView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="never"
android:scrollbars="none"
android:visibility="visible"
/>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:layout_gravity="end|bottom"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="36dp"
android:layout_marginBottom="41dp"
android:contentDescription="add"
android:src="@drawable/ic_action_name" />
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/constraintlayout_none"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="2dp"
android:layout_marginTop="48dp"
android:layout_marginEnd="-2dp"
android:layout_marginBottom="461dp"
android:background="@color/hui"
android:visibility="gone">
<EditText
android:id="@+id/text_add"
android:layout_width="294dp"
android:layout_height="58dp"
android:layout_marginTop="4dp"
android:ems="10"
android:hint="Please enter..."
android:imeOptions="actionNext"
android:inputType="text"
android:minHeight="48dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/button_cl"
android:layout_width="117dp"
android:layout_height="wrap_content"
android:layout_marginTop="36dp"
android:text="Cancel"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/button_ok"
app:layout_constraintHorizontal_bias="0.444"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/text_add"
app:layout_constraintVertical_bias="0.0" />
<Button
android:id="@+id/button_ok"
android:layout_width="137dp"
android:layout_height="48dp"
android:layout_marginTop="36dp"
android:layout_marginEnd="32dp"
android:text="Confirm"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@+id/text_add"
app:layout_constraintVertical_bias="0.0" />
</androidx.constraintlayout.widget.ConstraintLayout>
</RelativeLayout>
The input box starts in a hidden state
Java Part#
Set the content of three components in onBindViewHolder
holder.textView1.setText("" + position);//Convert to string
holder.textView2.setText(list.get(position));
holder.imageView_item1.setImageResource(addimg(position));
Listener in onBindViewHolder
holder.linearLayout_item1.setOnTouchListener(new View.OnTouchListener() {
private int X;
private int lastX;
private int Y;
@SuppressLint("ResourceAsColor")
@Override
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN://Triggered when the first touch point is detected on the screen.
lastX = (int) event.getRawX();
Y = (int) event.getRawY();
X = (int) event.getRawX();
break;
case MotionEvent.ACTION_UP://Triggered when the touch point is released.
if (Math.abs((int) event.getRawX() - X)<2){//Single click, no change in click coordinates
Intent intent = new Intent(holder.itemView.getContext(), MainActivity2.class);
intent.putExtra("msg","position:"+position+"\n"+list.get(position));
context.startActivity(intent);
}
if(Math.abs(((int) event.getRawX() - X))<200){
holder.linearLayout_item1.setLeft(0);
}else{
onSwiped(position);
holder.linearLayout_item1.setLeft(0);
}
break;
case MotionEvent.ACTION_MOVE:
int dx = (int) event.getRawX() - lastX;
int left = view.getLeft() + dx;
holder.linearLayout_item1.setLeft(left);
lastX = (int) event.getRawX();
break;
}
return true;
}
});
Several triggered events of MotionEvent, currently there is a bug. The judgment of vertical scrolling and horizontal sliding
Judgment of dragging or clicking: based on the difference in coordinates between touch and release within a certain range
Delete Data
// Delete data
@SuppressLint("NotifyDataSetChanged")
public void onSwiped(int p) {
list.remove(p);
notifyItemRemoved(p);
notifyDataSetChanged();
}
In Fragment.java, Viewinit() function
private void Viewinit() {
context = this.getActivity();
//fullview=getView();
myadapter = new Adapter(context);
//Set LayoutManager
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(context);
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setHasFixedSize(true);
recyclerView.setAdapter(myadapter);
myadapter.list(list);
}
Adding to the list
@SuppressLint("NotifyDataSetChanged")
@Override
public void onStart() {
super.onStart();
fab=getActivity().findViewById(R.id.fab);
ConstraintLayout constraintlayout_none=getActivity().findViewById(R.id.constraintlayout_none);
EditText text_add=getActivity().findViewById(R.id.text_add);
Button button_cl=getActivity().findViewById(R.id.button_cl);
Button button_ok=getActivity().findViewById(R.id.button_ok);
InputMethodManager imm = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE); ;
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
constraintlayout_none.setVisibility(View.VISIBLE);
recyclerView.setVisibility(View.INVISIBLE);
imm.showSoftInput(text_add, 0);
text_add.setText("");
button_ok.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String s=text_add.getText().toString();
constraintlayout_none.setVisibility(View.GONE);
list.add(s);
Log.d("add","+1");
imm.hideSoftInputFromWindow(text_add.getWindowToken(), 0);
myadapter.notifyDataSetChanged();
recyclerView.scrollToPosition(myadapter.getItemCount() - 1);
Toast.makeText(context, "Added successfully", Toast.LENGTH_SHORT).show();
recyclerView.setVisibility(View.VISIBLE);
}
});
button_cl.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
constraintlayout_none.setVisibility(View.GONE);
Toast.makeText(context, "Add canceled", Toast.LENGTH_SHORT).show();
recyclerView.setVisibility(View.VISIBLE);
imm.hideSoftInputFromWindow(text_add.getWindowToken(), 0);
}
});
//list.add("111111");
//Log.d("add",list.toString());
}
});
}
The idea is to show the input layout after clicking the add button, hide the RecyclerView, and open the keyboard.
-
If you click
Confirm, the input value will be added to the list, refresh the RecyclerView, hide the input layout, close the keyboard, and show the RecyclerView. -
If you click
Cancel, directly restore the view (i.e., hide the input layout, show the RecyclerView...)
Complete Code#
Adapter.java
package com.example.applicationtest;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;
public class Adapter extends RecyclerView.Adapter<Adapter.Myholder> {
private View itemview;
private Context context;
private List<String> list;
public int addimg(int i) {
if (i % 4 == 0) {
return R.drawable.num_a;
} else if (i % 4 - 1 == 0) {
return R.drawable.num_b;
} else if (i % 4 - 2 == 0) {
return R.drawable.num_c;
} else if (i % 4 - 3 == 0) {
return R.drawable.num_d;
} else {
return R.drawable.ic___fx;
}
}
public Adapter(Context context) {
this.context = context;
}
public void list(List<String> list) {
this.list = list;
notifyDataSetChanged();
}
@NonNull
@Override
public Myholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
itemview = LayoutInflater.from(context).inflate(R.layout.item1, parent, false);
Myholder holder;
holder = new Myholder(itemview);
return holder;
}
@SuppressLint({"SetTextI18n", "ClickableViewAccessibility"})
@Override
public void onBindViewHolder(@NonNull Myholder holder, @SuppressLint("RecyclerView") int position) {
holder.textView1.setText("" + position);//Convert to string
holder.textView2.setText(list.get(position));
holder.imageView_item1.setImageResource(addimg(position));
// holder.linearLayout_item1.setOnClickListener(new View.OnClickListener() {
// @Override
// public void onClick(View view) {
// //Toast.makeText(itemview.getContext(), position + "号:" + list.get(position), Toast.LENGTH_SHORT).show();
// Intent intent = new Intent(holder.itemView.getContext(), MainActivity2.class);
// intent.putExtra("msg","position:"+position+"\n"+list.get(position));
// context.startActivity(intent);
// //onSwiped(position);
// }
// });
holder.linearLayout_item1.setOnTouchListener(new View.OnTouchListener() {
private int X;
private int lastX;
private int Y;
@SuppressLint("ResourceAsColor")
@Override
public boolean onTouch(View view, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN://Triggered when the first touch point is detected on the screen.
lastX = (int) event.getRawX();
Y = (int) event.getRawY();
X = (int) event.getRawX();
break;
case MotionEvent.ACTION_UP://Triggered when the touch point is released.
if (Math.abs((int) event.getRawX() - X)<2){//Single click, no change in click coordinates
Intent intent = new Intent(holder.itemView.getContext(), MainActivity2.class);
intent.putExtra("msg","position:"+position+"\n"+list.get(position));
context.startActivity(intent);
}
if(Math.abs(((int) event.getRawX() - X))<200){
holder.linearLayout_item1.setLeft(0);
}else{
onSwiped(position);
holder.linearLayout_item1.setLeft(0);
}
break;
case MotionEvent.ACTION_MOVE:
int dx = (int) event.getRawX() - lastX;
int left = view.getLeft() + dx;
holder.linearLayout_item1.setLeft(left);
lastX = (int) event.getRawX();
break;
}
return true;
}
});
}
// Delete data
@SuppressLint("NotifyDataSetChanged")
public void onSwiped(int p) {
list.remove(p);
notifyItemRemoved(p);
notifyDataSetChanged();
}
@Override
public int getItemCount() {
return list.size();
}
public static class Myholder extends RecyclerView.ViewHolder {
private TextView textView1, textView2;
private ImageView imageView_item1;
private LinearLayout linearLayout_item1;
public Myholder(@NonNull View itemView) {
super(itemView);
textView1 = itemView.findViewById(R.id.textView_item1);
textView2 = itemView.findViewById(R.id.textView_item2);
imageView_item1 = itemView.findViewById(R.id.imageView_item1);
linearLayout_item1 = itemView.findViewById(R.id.linearLayout_item1);
}
}
}
Fragment2.java
package com.example.applicationtest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.text.InputType;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import androidx.constraintlayout.widget.ConstraintLayout;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import javax.security.auth.PrivateCredentialPermission;
public class Fragment2 extends Fragment {
private RecyclerView recyclerView;
private Context context;
private FloatingActionButton fab;
private Adapter myadapter;
private List<String> list = new ArrayList<>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view;
view = inflater.inflate(R.layout.tab02, container, false);
recyclerView = view.findViewById(R.id.recyclerView1);
listdata();
Viewinit();
return view;
}
@SuppressLint("NotifyDataSetChanged")
@Override
public void onStart() {
super.onStart();
fab=getActivity().findViewById(R.id.fab);
ConstraintLayout constraintlayout_none=getActivity().findViewById(R.id.constraintlayout_none);
EditText text_add=getActivity().findViewById(R.id.text_add);
Button button_cl=getActivity().findViewById(R.id.button_cl);
Button button_ok=getActivity().findViewById(R.id.button_ok);
InputMethodManager imm = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE); ;
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
constraintlayout_none.setVisibility(View.VISIBLE);
recyclerView.setVisibility(View.INVISIBLE);
imm.showSoftInput(text_add, 0);
text_add.setText("");
button_ok.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
String s=text_add.getText().toString();
constraintlayout_none.setVisibility(View.GONE);
list.add(s);
Log.d("add","+1");
imm.hideSoftInputFromWindow(text_add.getWindowToken(), 0);
myadapter.notifyDataSetChanged();
recyclerView.scrollToPosition(myadapter.getItemCount() - 1);
Toast.makeText(context, "Added successfully", Toast.LENGTH_SHORT).show();
recyclerView.setVisibility(View.VISIBLE);
}
});
button_cl.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
constraintlayout_none.setVisibility(View.GONE);
Toast.makeText(context, "Add canceled", Toast.LENGTH_SHORT).show();
recyclerView.setVisibility(View.VISIBLE);
imm.hideSoftInputFromWindow(text_add.getWindowToken(), 0);
}
});
//list.add("111111");
//Log.d("add",list.toString());
}
});
}
private void Viewinit() {
context = this.getActivity();
//fullview=getView();
myadapter = new Adapter(context);
//Set LayoutManager
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(context);
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setHasFixedSize(true);
recyclerView.setAdapter(myadapter);
myadapter.list(list);
}
private void listdata() {
list.add("Bright sunshine and bright girls······ do they match well?");
list.add("Don't move, let me borrow your eyes to look in the mirror. Do you feel nostalgic?");
list.add("Are my eyes beautiful? This is not colored contact lenses, it's the magic of a beautiful girl.");
...
}
}
3. Experiment Summary#
-
Inherit from
RecyclerView.ViewHolderand write your ownViewHolder. -
Implement
onCreateViewHolder(ViewGroup parent, int viewType)
This method will be called when the RecyclerView needs us to provide a new ViewHolder of type viewType. Instantiate the root layout ofItemand return a ViewHolder bound to it. -
Implement
onBindViewHolder(VH viewHolder, int position)
This method will be called when the RecyclerView needs to display the data corresponding to the position. Update the view through the View held by the viewHolder at the corresponding position. -
Implement getItemCount()
Return the total number of Items.