android studio开发记事本app的代码
时间: 2023-12-05 20:04:45 浏览: 64
好的,以下是一个简单的Android Studio记事本应用程序的代码:
1. 首先,在布局文件中创建一个EditText组件用于用户输入:
```
<EditText
android:id="@+id/editText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter your notes..."
android:textSize="16sp" />
```
2. 在MainActivity.java文件中,获取EditText组件并将其内容保存到本地文件中:
```
public class MainActivity extends AppCompatActivity {
private EditText editText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = findViewById(R.id.editText);
// Load saved notes
String savedNotes = loadNotes();
editText.setText(savedNotes);
}
// Save notes to local file
private void saveNotes() {
try {
FileOutputStream fileOutputStream = openFileOutput("notes.txt", MODE_PRIVATE);
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);
outputStreamWriter.write(editText.getText().toString());
outputStreamWriter.close();
} catch (Exception e) {
e.printStackTrace();
}
}
// Load saved notes from local file
private String loadNotes() {
String notes = "";
try {
FileInputStream fileInputStream = openFileInput("notes.txt");
InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String line;
while ((line = bufferedReader.readLine()) != null) {
notes += line;
}
bufferedReader.close();
} catch (Exception e) {
e.printStackTrace();
}
return notes;
}
// Save notes when user leaves the app
@Override
protected void onPause() {
super.onPause();
saveNotes();
}
}
```
3. 最后,在AndroidManifest.xml文件中添加以下权限:
```
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
```
这个简单的记事本应用程序现在就可以在Android设备上运行了。