Android studio做一个个人笔记小程序详细代码

以下是一个简单的Android Studio个人笔记小程序的代码实现，代码注释已经做了详细说明，希望对你有所帮助：

1. MainActivity.java

package com.example.notes;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private Button addNoteButton;
    private ArrayList<Note> notesList; // 用于存储笔记数据的列表
    private NotesAdapter notesAdapter; // 用于将数据绑定到recyclerview上的适配器

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = findViewById(R.id.recyclerView);
        addNoteButton = findViewById(R.id.addNoteButton);

        // 设置recyclerview的布局管理器
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        // 初始化笔记列表
        notesList = new ArrayList<>();

        // 创建适配器并将其绑定到recyclerview上
        notesAdapter = new NotesAdapter(notesList);
        recyclerView.setAdapter(notesAdapter);

        // 监听添加笔记按钮的点击事件
        addNoteButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this, AddNoteActivity.class);
                startActivityForResult(intent, 1);
            }
        });
    }

    // 处理添加笔记界面返回的数据
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 1 && resultCode == RESULT_OK) {
            String title = data.getStringExtra("title");
            String content = data.getStringExtra("content");

            // 将新笔记添加到列表中
            notesList.add(new Note(title, content));
            notesAdapter.notifyDataSetChanged(); // 刷新recyclerview
        }
    }
}

2. Note.java

package com.example.notes;

public class Note {
    private String title;
    private String content;

    public Note(String title, String content) {
        this.title = title;
        this.content = content;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

3. NotesAdapter.java

package com.example.notes;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;

public class NotesAdapter extends RecyclerView.Adapter<NotesViewHolder> {

    private ArrayList<Note> notesList;

    public NotesAdapter(ArrayList<Note> notesList) {
        this.notesList = notesList;
    }

    @NonNull
    @Override
    public NotesViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.note_item, parent, false);
        return new NotesViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull NotesViewHolder holder, int position) {
        Note note = notesList.get(position);
        holder.bind(note);
    }

    @Override
    public int getItemCount() {
        return notesList.size();
    }
}

4. NotesViewHolder.java

package com.example.notes;

import android.view.View;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

public class NotesViewHolder extends RecyclerView.ViewHolder {

    private TextView titleTextView;
    private TextView contentTextView;

    public NotesViewHolder(@NonNull View itemView) {
        super(itemView);

        titleTextView = itemView.findViewById(R.id.titleTextView);
        contentTextView = itemView.findViewById(R.id.contentTextView);
    }

    public void bind(Note note) {
        titleTextView.setText(note.getTitle());
        contentTextView.setText(note.getContent());
    }
}

5. AddNoteActivity.java

package com.example.notes;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class AddNoteActivity extends AppCompatActivity {

    private EditText titleEditText;
    private EditText contentEditText;
    private Button saveButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add_note);

        titleEditText = findViewById(R.id.titleEditText);
        contentEditText = findViewById(R.id.contentEditText);
        saveButton = findViewById(R.id.saveButton);

        saveButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.putExtra("title", titleEditText.getText().toString());
                intent.putExtra("content", contentEditText.getText().toString());
                setResult(RESULT_OK, intent); // 设置结果码和返回数据
                finish(); // 关闭当前activity
            }
        });
    }
}

6. note_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

    <TextView
        android:id="@+id/titleTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/contentTextView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:textSize="16sp" />

</LinearLayout>

7. activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/addNoteButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Add Note"
        android:layout_margin="16dp"/>

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</LinearLayout>

8. activity_add_note.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".AddNoteActivity">

    <EditText
        android:id="@+id/titleEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Title"
        android:textSize="20sp"
        android:textStyle="bold"
        android:padding="16dp" />

    <EditText
        android:id="@+id/contentEditText"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:hint="Content"
        android:textSize="16sp"
        android:padding="16dp" />

    <Button
        android:id="@+id/saveButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Save"
        android:layout_gravity="end"
        android:layout_margin="16dp"/>

</LinearLayout>

以上就是一个简单的Android Studio个人笔记小程序的代码实现，希望对你有所帮助。