android studio记事本源码

以下是一个简单的 Android Studio 记事本应用程序的源代码示例：

package com.example.notebook;

import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class MainActivity extends AppCompatActivity {
    EditText editText;

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

        editText = findViewById(R.id.editText);

        try {
            FileInputStream fileInputStream = openFileInput("notes.txt");
            InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String line;
            StringBuilder stringBuilder = new StringBuilder();

            while ((line = bufferedReader.readLine()) != null) {
                stringBuilder.append(line).append("\n");
            }

            editText.setText(stringBuilder.toString());

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void save(View view) {
        try {
            FileOutputStream fileOutputStream = openFileOutput("notes.txt", MODE_PRIVATE);
            fileOutputStream.write(editText.getText().toString().getBytes());
            fileOutputStream.close();
            Toast.makeText(this, "Saved", Toast.LENGTH_SHORT).show();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

请注意，这只是一个简单的示例，没有考虑许多实际应用程序中需要考虑的因素。