自己写的一个简单的android记事本app |
您所在的位置：网站首页 › 自己写剧本的app › 自己写的一个简单的android记事本app |
自己写的一个简单的android记事本app
|
自己写的一个简单的记事本app，效果如下：
一、首先是第一个界面的编写，最上面是一个TextView，中间是一个Linearlayout中嵌套一个listview布局，最下面是一个button。下面附上第一个页面的简单布局xml文件。 至于button的样式btn_selector就是自己定义的button样式。 二、其次就是设置ListView中数据显示的xml文件，代码如下：
三、编写第二个界面样式，第二个界面是最上面一个linearlayout，里面包含两个button和一个TextView。代码如下： 四、将日志的数据保存在数据库中，使用sqlite来创建数据库，数据库中有三个属性，"_id"、"content"、"date"这三个属性，创建一个NoteDB来创建数据库。 package com.example.datenote; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; public class NotesDB extends SQLiteOpenHelper { public static final String TABLE_NAME_NOTES = "note"; public static final String COLUMN_NAME_ID = "_id"; public static final String COLUMN_NAME_NOTE_CONTENT = "content"; public static final String COLUMN_NAME_NOTE_DATE = "date"; public NotesDB(Context context) { super(context, "note", null, 1); // TODO Auto-generated constructor stub } @Override public void onCreate(SQLiteDatabase db) { String sql = "CREATE TABLE " + TABLE_NAME_NOTES + "(" + COLUMN_NAME_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_NAME_NOTE_CONTENT + " TEXT NOT NULL DEFAULT\"\"," + COLUMN_NAME_NOTE_DATE + " TEXT NOT NULL DEFAULT\"\"" + ")"; Log.d("SQL", sql); db.execSQL(sql); // String sql1="insert into "+TABLE_NAME_NOTES+"values("+"1,"+"'写作业',"+"'晚上要写作业的干活'"+")"; // Log.d("SQL1", sql1); // db.execSQL(sql1); // ContentValues values=new ContentValues(); // values.put("id",1); // values.put("content","写作业"); // values.put("date", "2013-1-2"); // db.insert("note", null, values); } @Override public void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) { // TODO Auto-generated method stub } }五、、实现点击添加事件的跳转,在第一个页面中点击添加备忘录后会跳转到第二个界面，设置点击事件，由一个activity跳转到另外一个activity，我使用的是intent方式。另外，在ListView中点击每个已记录下来的日志也会跳转到第二个界面，只是显示的不是空白的EditText，而是包含日志的EditText。MainActivity如下： package com.example.datenote; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.Activity; import android.app.AlertDialog; import android.app.AlertDialog.Builder; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.view.Window; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.AdapterView.OnItemLongClickListener; import android.widget.Button; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends Activity implements OnScrollListener, OnItemClickListener, OnItemLongClickListener { private Context mContext; private ListView listview; private SimpleAdapter simp_adapter; private List dataList; private Button addNote; private TextView tv_content; private NotesDB DB; private SQLiteDatabase dbread; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.activity_main); tv_content = (TextView) findViewById(R.id.tv_content); listview = (ListView) findViewById(R.id.listview); dataList = new ArrayList(); addNote = (Button) findViewById(R.id.btn_editnote); mContext = this; addNote.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { noteEdit.ENTER_STATE = 0; Intent intent = new Intent(mContext, noteEdit.class); Bundle bundle = new Bundle(); bundle.putString("info", ""); intent.putExtras(bundle); startActivityForResult(intent, 1); } }); DB = new NotesDB(this); dbread = DB.getReadableDatabase(); // 清空数据库中表的内容 //dbread.execSQL("delete from note"); RefreshNotesList(); listview.setOnItemClickListener(this); listview.setOnItemLongClickListener(this); listview.setOnScrollListener(this); } public void RefreshNotesList() { int size = dataList.size(); if (size > 0) { dataList.removeAll(dataList); simp_adapter.notifyDataSetChanged(); listview.setAdapter(simp_adapter); } simp_adapter = new SimpleAdapter(this, getData(), R.layout.item, new String[] { "tv_content", "tv_date" }, new int[] { R.id.tv_content, R.id.tv_date }); listview.setAdapter(simp_adapter); } private List getData() { Cursor cursor = dbread.query("note", null, "content!=\"\"", null, null, null, null); while (cursor.moveToNext()) { String name = cursor.getString(cursor.getColumnIndex("content")); String date = cursor.getString(cursor.getColumnIndex("date")); Map map = new HashMap(); map.put("tv_content", name); map.put("tv_date", date); dataList.add(map); } cursor.close(); return dataList; } @Override public void onScroll(AbsListView arg0, int arg1, int arg2, int arg3) { // TODO Auto-generated method stub } // 滑动listview监听事件 @Override public void onScrollStateChanged(AbsListView arg0, int arg1) { // TODO Auto-generated method stub switch (arg1) { case SCROLL_STATE_FLING: Log.i("main", "用户在手指离开屏幕之前，由于用力的滑了一下，视图能依靠惯性继续滑动"); case SCROLL_STATE_IDLE: Log.i("main", "视图已经停止滑动"); case SCROLL_STATE_TOUCH_SCROLL: Log.i("main", "手指没有离开屏幕，试图正在滑动"); } } // 点击listview中某一项的监听事件 @Override public void onItemClick(AdapterView arg0, View arg1, int arg2, long arg3) { noteEdit.ENTER_STATE = 1; // Log.d("arg2", arg2 + ""); // TextView // content=(TextView)listview.getChildAt(arg2).findViewById(R.id.tv_content); // String content1=content.toString(); String content = listview.getItemAtPosition(arg2) + ""; String content1 = content.substring(content.indexOf("=") + 1, content.indexOf(",")); Log.d("CONTENT", content1); Cursor c = dbread.query("note", null, "content=" + "'" + content1 + "'", null, null, null, null); while (c.moveToNext()) { String No = c.getString(c.getColumnIndex("_id")); Log.d("TEXT", No); // Intent intent = new Intent(mContext, noteEdit.class); // intent.putExtra("data", text); // setResult(4, intent); // // intent.putExtra("data",text); // startActivityForResult(intent, 3); Intent myIntent = new Intent(); Bundle bundle = new Bundle(); bundle.putString("info", content1); noteEdit.id = Integer.parseInt(No); myIntent.putExtras(bundle); myIntent.setClass(MainActivity.this, noteEdit.class); startActivityForResult(myIntent, 1); } } @Override // 接受上一个页面返回的数据，并刷新页面 protected void onActivityResult(int requestCode, int resultCode, Intent data) { // TODO Auto-generated method stub super.onActivityResult(requestCode, resultCode, data); if (requestCode == 1 && resultCode == 2) { RefreshNotesList(); } } // 点击listview中某一项长时间的点击事件 @Override public boolean onItemLongClick(AdapterView arg0, View arg1, int arg2, long arg3) { final int n=arg2; Builder builder = new AlertDialog.Builder(this); builder.setTitle("删除该日志"); builder.setMessage("确认删除吗？"); builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { String content = listview.getItemAtPosition(n) + ""; String content1 = content.substring(content.indexOf("=") + 1, content.indexOf(",")); Cursor c = dbread.query("note", null, "content=" + "'" + content1 + "'", null, null, null, null); while (c.moveToNext()) { String id = c.getString(c.getColumnIndex("_id")); String sql_del = "update note set content='' where _id=" + id; dbread.execSQL(sql_del); RefreshNotesList(); } } }); builder.setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }); builder.create(); builder.show(); return true; } }六、编写第二个跳转后界面的Activity，如下： package com.example.datenote; import java.text.SimpleDateFormat; import java.util.Date; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteStatement; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.view.Window; import android.view.WindowManager; import android.view.inputmethod.InputMethodManager; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; public class noteEdit extends Activity { private TextView tv_date; private EditText et_content; private Button btn_ok; private Button btn_cancel; private NotesDB DB; private SQLiteDatabase dbread; public static int ENTER_STATE = 0; public static String last_content; public static int id; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); // 设置无标题 requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.edit); tv_date = (TextView) findViewById(R.id.tv_date); Date date = new Date(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm"); String dateString = sdf.format(date); tv_date.setText(dateString); et_content = (EditText) findViewById(R.id.et_content); // 设置软键盘自动弹出 getWindow().setSoftInputMode( WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE); DB = new NotesDB(this); dbread = DB.getReadableDatabase(); Bundle myBundle = this.getIntent().getExtras(); last_content = myBundle.getString("info"); Log.d("LAST_CONTENT", last_content); et_content.setText(last_content); // 确认按钮的点击事件 btn_ok = (Button) findViewById(R.id.btn_ok); btn_ok.setOnClickListener(new OnClickListener() { public void onClick(View arg0) { // 获取日志内容 String content = et_content.getText().toString(); Log.d("LOG1", content); // 获取写日志时间 Date date = new Date(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); String dateNum = sdf.format(date); String sql; String sql_count = "SELECT COUNT(*) FROM note"; SQLiteStatement statement = dbread.compileStatement(sql_count); long count = statement.simpleQueryForLong(); Log.d("COUNT", count + ""); Log.d("ENTER_STATE", ENTER_STATE + ""); // 添加一个新的日志 if (ENTER_STATE == 0) { if (!content.equals("")) { sql = "insert into " + NotesDB.TABLE_NAME_NOTES + " values(" + count + "," + "'" + content + "'" + "," + "'" + dateNum + "')"; Log.d("LOG", sql); dbread.execSQL(sql); } } // 查看并修改一个已有的日志 else { Log.d("执行命令", "执行了该函数"); String updatesql = "update note set content='" + content + "' where _id=" + id; dbread.execSQL(updatesql); // et_content.setText(last_content); } Intent data = new Intent(); setResult(2, data); finish(); } }); btn_cancel = (Button) findViewById(R.id.btn_cancel); btn_cancel.setOnClickListener(new OnClickListener() { public void onClick(View arg0) { finish(); } }); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { // TODO Auto-generated method stub super.onActivityResult(requestCode, resultCode, data); // if (requestCode == 3 && resultCode == 4) { // last_content=data.getStringExtra("data"); // Log.d("LAST_STRAING", last_content+"gvg"); // } } }七、其中，对ListView添加OnItemLongclicklistener，长点击之后会弹出一个dialog对话框提醒要不要删除该日志文件。 public boolean onItemLongClick(AdapterView arg0, View arg1, int arg2, long arg3) { final int n=arg2; Builder builder = new AlertDialog.Builder(this); builder.setTitle("删除该日志"); builder.setMessage("确认删除吗？"); builder.setPositiveButton("确定", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { String content = listview.getItemAtPosition(n) + ""; String content1 = content.substring(content.indexOf("=") + 1, content.indexOf(",")); Cursor c = dbread.query("note", null, "content=" + "'" + content1 + "'", null, null, null, null); while (c.moveToNext()) { String id = c.getString(c.getColumnIndex("_id")); String sql_del = "update note set content='' where _id=" + id; dbread.execSQL(sql_del); RefreshNotesList(); } } }); builder.setNegativeButton("取消", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { } }); builder.create(); builder.show(); return true; }注意最后将返回值设为true，否则会和OnItemClickListener产生冲突。 附上长点击删除的效果。
由于Android6.0以上读写权限需要手动申请，可能会导致保存之后显示不出来，需要手动加上权限申请： //android6.0之后要动态获取权限 private void checkPermission() { // Storage Permissions final int REQUEST_EXTERNAL_STORAGE = 1; String[] PERMISSIONS_STORAGE = { Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE}; try { //检测是否有写的权限 int permission = ActivityCompat.checkSelfPermission(MainActivity.this, "android.permission.WRITE_EXTERNAL_STORAGE"); if (permission != PackageManager.PERMISSION_GRANTED) { // 没有写的权限，去申请写的权限，会弹出对话框 ActivityCompat.requestPermissions(MainActivity.this, PERMISSIONS_STORAGE, REQUEST_EXTERNAL_STORAGE); } } catch (Exception e) { e.printStackTrace(); } }已更新到github上，自行下载。 由于很多人去csdn下载资源分不够，现将代码上传到github，大家自行下载。 |
【本文地址】