Android 备忘录 Android 备忘录的实现流程详解
猪小温 人气:0想了解Android 备忘录的实现流程详解的相关内容吗，猪小温在本文为您仔细讲解Android 备忘录的相关知识和一些Code实例，欢迎阅读和指正，我们先划重点：Android,备忘录,Android,记事本，下面大家一起来学习吧。
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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
总结
有写的各位看起来不适应的可以 评论指导
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