Android备忘录（笔记）简单实现有源码注释详细_猪小温_android studio备忘录代码

大大的周 02-07 4446

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文章目录一、首先创建保存数据的表二、主界面2.1 activity_main.xml 三、:EditActivity.java3.1 edit_layout.xml 四、对笔记进行增删查改4.1 note_layout.xml 五、演示效果5.1 登录界面5.2笔记界面5.3 增加记录5.4删除记录5.5 查找记录5.6源码总结

一、首先创建保存数据的表

Notedatabase,java

package com.example.biji_1; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public class NoteDatabase extends SQLiteOpenHelper { public static final String TABLE_NAME ="notes"; public static final String CONTENT ="content"; public static final String ID ="_id"; public static final String TIME ="time"; public static final String MODE ="mode"; public NoteDatabase(Context context){ super(context,"notes",null,1); } @Override public void onCreate(SQLiteDatabase db){ db.execSQL("CREATE TABLE " + TABLE_NAME + "(" + ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + CONTENT + " TEXT NOT NULL, " + TIME + " TEXT NOT NULL, " + MODE + " INTEGER DEFAULT 1)"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion,int newVersion){ } } 二、主界面

MainAcitivity.java

public class MainActivity extends BaseActivity implements AdapterView.OnItemClickListener { //test gittt private NoteDatabase dbHelper; private Context context = this; final String TAG = "tag"; FloatingActionButton btn; private ListView lv; private NoteAdapter adapter; private List<Note> noteList = new ArrayList<Note>(); private Toolbar myToolbar; //弹出菜单 private PopupWindow popupWindow; private PopupWindow popupCover; private ViewGroup customView; private ViewGroup coverView; private LayoutInflater layoutInflater; private RelativeLayout main; private WindowManager wm; private DisplayMetrics metrics; private TextView setting_text; private ImageView setting_image; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initPrefs(); btn = (FloatingActionButton) findViewById(R.id.fab); lv = findViewById(R.id.lv); myToolbar = findViewById(R.id.myToolbar); adapter = new NoteAdapter(getApplicationContext(), noteList); refreshListView(); lv.setAdapter(adapter); setSupportActionBar(myToolbar); getSupportActionBar().setHomeButtonEnabled(true); getSupportActionBar().setDisplayHomeAsUpEnabled(true); //设置toolbar取代actionbar initPopUpView(); myToolbar.setNavigationIcon(R.drawable.ic_baseline_menu_24); myToolbar.setNavigationOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Log.d(TAG, "onClick: shit"); showPopUpView(); } }); lv.setOnItemClickListener(this); btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(MainActivity.this, EditActivity.class); intent.putExtra("mode", 4); startActivityForResult(intent, 0); } }); } public void initPopUpView(){ layoutInflater = (LayoutInflater) MainActivity.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE); customView = (ViewGroup) layoutInflater.inflate(R.layout.setting_layout, null); coverView = (ViewGroup) layoutInflater.inflate(R.layout.setting_cover, null); main = findViewById(R.id.main_layout); wm = getWindowManager(); metrics = new DisplayMetrics(); wm.getDefaultDisplay().getMetrics(metrics); } public void showPopUpView(){ int width = metrics.widthPixels; int height = metrics.heightPixels; popupCover = new PopupWindow(coverView, width, height, false); popupWindow = new PopupWindow(customView, (int) (width * 0.7), height, true); popupWindow.setBackgroundDrawable(new ColorDrawable(Color.WHITE)); //在主界面加载成功之后显示弹出 findViewById(R.id.main_layout).post(new Runnable() { @Override public void run() { popupCover.showAtLocation(main, Gravity.NO_GRAVITY, 0, 0); popupWindow.showAtLocation(main, Gravity.NO_GRAVITY, 0, 0); setting_image = customView.findViewById(R.id.setting_settings_image); setting_text = customView.findViewById(R.id.setting_settings_text); setting_image.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { startActivity(new Intent(MainActivity.this, UserSettingsActivity.class)); } }); setting_text.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { startActivity(new Intent(MainActivity.this, UserSettingsActivity.class)); } }); coverView.setOnTouchListener(new View.OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { popupWindow.dismiss(); return true; } }); popupWindow.setOnDismissListener(new PopupWindow.OnDismissListener() { @Override public void onDismiss() { popupCover.dismiss(); Log.d(TAG, "onDismiss: test"); } }); } }); } public void initPrefs(){ SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getBaseContext()); SharedPreferences.Editor editor = sharedPreferences.edit(); if (!sharedPreferences.contains("nightMode")) { editor.putBoolean("nightMode", false); editor.commit(); } } // 接受startActivityForResult的结果 @Override protected void onActivityResult(int requestCode, int resultCode, Intent data){ int returnMode; long note_Id; returnMode = data.getExtras().getInt("mode", -1); note_Id = data.getExtras().getLong("id", 0); if (returnMode == 1) { //update current note String content = data.getExtras().getString("content"); String time = data.getExtras().getString("time"); int tag = data.getExtras().getInt("tag", 1); Note newNote = new Note(content, time, tag); newNote.setId(note_Id); CRUD op = new CRUD(context); op.open(); op.updateNote(newNote); op.close(); } else if (returnMode == 0) { // create new note String content = data.getExtras().getString("content"); String time = data.getExtras().getString("time"); int tag = data.getExtras().getInt("tag", 1); Note newNote = new Note(content, time, tag); CRUD op = new CRUD(context); op.open(); op.addNote(newNote); op.close(); } else if (returnMode == 2) { // delete Note curNote = new Note(); curNote.setId(note_Id); CRUD op = new CRUD(context); op.open(); op.removeNote(curNote); op.close(); } else{ } refreshListView(); super.onActivityResult(requestCode, resultCode, data); } //判断笔记状态 @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main_menu, menu); //search setting MenuItem mSearch = menu.findItem(R.id.action_search); SearchView mSearchView = (SearchView) mSearch.getActionView(); mSearchView.setQueryHint("请输入搜索内容"); mSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() { @Override public boolean onQueryTextSubmit(String query) { return false; } @Override public boolean onQueryTextChange(String newText) { adapter.getFilter().filter(newText); return false; } }); return super.onCreateOptionsMenu(menu); } //搜索 @Override public boolean onOptionsItemSelected(MenuItem item){ switch (item.getItemId()){ case R.id.menu_clear: new AlertDialog.Builder(MainActivity.this) .setMessage("删除全部吗？") .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dbHelper = new NoteDatabase(context); SQLiteDatabase db = dbHelper.getWritableDatabase(); db.delete("notes", null, null); db.execSQL("update sqlite_sequence set seq=0 where name='notes'"); refreshListView(); } }).setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }).create().show(); break; } return super.onOptionsItemSelected(item); } //主界面删除 public void refreshListView(){ CRUD op = new CRUD(context); op.open(); // set adapter if (noteList.size() > 0) noteList.clear(); noteList.addAll(op.getAllNotes()); op.close(); adapter.notifyDataSetChanged(); } //刷新list @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { switch (parent.getId()) { case R.id.lv: Note curNote = (Note) parent.getItemAtPosition(position); Intent intent = new Intent(MainActivity.this, EditActivity.class); intent.putExtra("content", curNote.getContent()); intent.putExtra("id", curNote.getId()); intent.putExtra("time", curNote.getTime()); intent.putExtra("mode", 3); // MODE of 'click to edit' intent.putExtra("tag", curNote.getTag()); startActivityForResult(intent, 1); //collect data from edit Log.d(TAG, "onItemClick: " + position); break; } } //携带数据 } 2.1 activity_main.xml 三、:EditActivity.java package com.example.biji_1; import android.content.DialogInterface; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.KeyEvent; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.EditText; import androidx.appcompat.app.AlertDialog; import androidx.appcompat.widget.Toolbar; import java.text.SimpleDateFormat; import java.util.Date; public class EditActivity extends BaseActivity { EditText et; private Toolbar myToolbar; private String old_content = ""; private String old_time = ""; private int old_Tag = 1; private long id = 0; private int openMode = 0; private int tag = 1; public Intent intent = new Intent(); // message to be sent private boolean tagChange = false; private final String TAG = "tag"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.edit_layout); myToolbar = findViewById(R.id.myToolbar); setSupportActionBar(myToolbar); getSupportActionBar().setHomeButtonEnabled(true); getSupportActionBar().setDisplayHomeAsUpEnabled(true); //设置toolbar取代actionbar myToolbar.setNavigationOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { autoSetMessage(); setResult(RESULT_OK, intent); finish(); } }); myToolbar.setNavigationOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { autoSetMessage(); setResult(RESULT_OK, intent); finish(); } }); et = findViewById(R.id.et_1); Intent getIntent = getIntent(); openMode = getIntent.getIntExtra("mode", 0); if (openMode == 3) {//打开已存在的note id = getIntent.getLongExtra("id", 0); old_content = getIntent.getStringExtra("content"); old_time = getIntent.getStringExtra("time"); old_Tag = getIntent.getIntExtra("tag", 1); et.setText(old_content); et.setSelection(old_content.length()); Log.d("TAG","打开"); } } //渲染菜单栏 @Override public boolean onCreateOptionsMenu(Menu menu_1) { getMenuInflater().inflate(R.menu.edit_menu,menu_1); return super.onCreateOptionsMenu(menu_1); } @Override public boolean onOptionsItemSelected(MenuItem item){ switch (item.getItemId()){ case R.id.delete: new AlertDialog.Builder(EditActivity.this) .setMessage("删除吗？") .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { if (openMode == 4){ // new note intent.putExtra("mode", -1); setResult(RESULT_OK, intent); } else { // existing note intent.putExtra("mode", 2); intent.putExtra("id", id); setResult(RESULT_OK, intent); } finish(); } }).setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }).create().show(); break; } return super.onOptionsItemSelected(item); } public boolean onKeyDown(int keyCode, KeyEvent event){ if (keyCode == KeyEvent.KEYCODE_HOME){ return true; } else if (keyCode == KeyEvent.KEYCODE_BACK){ autoSetMessage(); setResult(RESULT_OK, intent); finish(); return true; } return super.onKeyDown(keyCode, event); } public void autoSetMessage(){ if(openMode == 4){ if(et.getText().toString().length() == 0){ intent.putExtra("mode", -1); //nothing new happens. } else{ intent.putExtra("mode", 0); // new one note; intent.putExtra("content", et.getText().toString()); intent.putExtra("time", dateToStr()); intent.putExtra("tag", tag); } } else { if (et.getText().toString().equals(old_content) && !tagChange) intent.putExtra("mode", -1); // edit nothing else { intent.putExtra("mode", 1); //edit the content intent.putExtra("content", et.getText().toString()); intent.putExtra("time", dateToStr()); intent.putExtra("id", id); intent.putExtra("tag", tag); } } } public String dateToStr(){ Date date = new Date(); SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); return simpleDateFormat.format(date); } } 3.1 edit_layout.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:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <androidx.appcompat.widget.Toolbar android:id="@+id/myToolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" android:elevation="4dp" app:titleTextColor="#FFEBCD" app:popupTheme="@style/ThemeOverlay.AppCompat.Light" /> <EditText android:id="@+id/et_1" android:layout_width="match_parent" android:layout_height="100dp" android:gravity="top" /> </LinearLayout> 四、对笔记进行增删查改

CRUD.java

package com.example.biji_1; import android.annotation.SuppressLint; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import java.util.ArrayList; import java.util.List; public class CRUD { SQLiteOpenHelper dbHandler; SQLiteDatabase db; private static final String[] columns = { NoteDatabase.ID, NoteDatabase.CONTENT, NoteDatabase.TIME, NoteDatabase.MODE }; public CRUD(Context context){ dbHandler = new NoteDatabase(context); } public void open(){ db = dbHandler.getWritableDatabase(); } public void close(){ dbHandler.close(); } //把note 加入到database里面 public Note addNote(Note note){ //add a note object to database ContentValues contentValues = new ContentValues(); contentValues.put(NoteDatabase.CONTENT, note.getContent()); contentValues.put(NoteDatabase.TIME, note.getTime()); contentValues.put(NoteDatabase.MODE, note.getTag()); long insertId = db.insert(NoteDatabase.TABLE_NAME, null, contentValues); note.setId(insertId); return note; } public Note getNote(long id){ //get a note from database using cursor index Cursor cursor = db.query(NoteDatabase.TABLE_NAME,columns,NoteDatabase.ID + "=?", new String[]{String.valueOf(id)},null,null, null, null); if (cursor != null) cursor.moveToFirst(); Note e = new Note(cursor.getString(1),cursor.getString(2), cursor.getInt(3)); return e; } @SuppressLint("Range") public List<Note> getAllNotes(){ Cursor cursor = db.query(NoteDatabase.TABLE_NAME,columns,null,null,null, null, null); List<Note> notes = new ArrayList<>(); if(cursor.getCount() > 0){ while(cursor.moveToNext()){ Note note = new Note(); note.setId(cursor.getLong(cursor.getColumnIndex(NoteDatabase.ID))); note.setContent(cursor.getString(cursor.getColumnIndex(NoteDatabase.CONTENT))); note.setTime(cursor.getString(cursor.getColumnIndex(NoteDatabase.TIME))); note.setTag(cursor.getInt(cursor.getColumnIndex(NoteDatabase.MODE))); notes.add(note); } } return notes; } //查找笔记 public int updateNote(Note note) { //update the info of an existing note ContentValues values = new ContentValues(); values.put(NoteDatabase.CONTENT, note.getContent()); values.put(NoteDatabase.TIME, note.getTime()); values.put(NoteDatabase.MODE, note.getTag()); // updating row return db.update(NoteDatabase.TABLE_NAME, values, NoteDatabase.ID + "=?",new String[] { String.valueOf(note.getId())}); } //更新笔记 public void removeNote(Note note) { //remove a note according to ID value db.delete(NoteDatabase.TABLE_NAME, NoteDatabase.ID + "=" + note.getId(), null); } //删除笔记 } 4.1 note_layout.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="match_parent" android:paddingLeft="10dp" android:paddingRight="10dp" android:paddingTop="5dp" android:paddingBottom="12dp" android:orientation="vertical" android:background="@drawable/note_shape"> <TextView android:id="@+id/tv_content" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Content" android:textSize="20dp" android:textColor=" #00F5FF" android:singleLine="true" /> <TextView android:id="@+id/tv_time" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Time" android:textSize="16dp" android:textColor=" #00F5FF"/> </LinearLayout> 五、演示效果 5.1 登录界面

哈哈界面随自己走各位别喷

5.2笔记界面

之前自己写的

5.3 增加记录

5.4删除记录

在主界面那个删除是删除全部会提示你然后你点击进去之后还有一个删除那条记录的删除键这里就不做演示了

5.5 查找记录

哈哈 ##5.6 改记录改之前改之后可以看到时间变化

其它效果靠这样演示不出来，源码在下面可以自取

5.6源码

上面给的代码不全 https://github.com/xiekangssq/local.git 有任何需要的可以私聊QQ 1833226220

总结