Android便签开发源码

Android 便签开发源码

首先我们来看一下app截图：

因为代码比较多，这里我把主要的代码贴出来， 源码链接：https://download.csdn.net/download/qq_40748996/11202859 GitHub：https://github.com/bbcode1/Notepad 程序结构图 activity_main.xml:

<?xml version="1.0" encoding="utf-8"?> <android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:fitsSystemWindows="true" tools:context="com.example.notes_2.MainActivity"> <RelativeLayout android:layout_width="match_parent" android:layout_height="match_parent"> <android.support.design.widget.AppBarLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:theme="@style/AppTheme.AppBarOverlay" android:id="@+id/aaa"> <android.support.v7.widget.Toolbar android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize" android:background="?attr/colorPrimary" app:popupTheme="@style/AppTheme.PopupOverlay" /> </android.support.design.widget.AppBarLayout> <ListView android:layout_below="@+id/aaa" android:id="@+id/listview_title" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1"> </ListView> <android.support.design.widget.FloatingActionButton android:id="@+id/fab" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="bottom|end" android:src="@android:drawable/ic_menu_add" android:layout_marginLeft="@dimen/fab_margin" android:layout_marginRight="@dimen/fab_margin" android:layout_alignBottom="@+id/listview_title" android:layout_centerHorizontal="true" /> </RelativeLayout> </android.support.design.widget.CoordinatorLayout>

content.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:orientation="vertical" > <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@color/colorPrimary" > <Button android:id="@+id/btn_ok" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="完成" android:background="@color/colorPrimary" /> <TextClock android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:format12Hour="yyyy年dd月MM日 HH:mm" /> <Button android:id="@+id/btn_cancle" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="取消" android:background="@color/colorPrimary" /> </LinearLayout> <EditText android:id="@+id/et_content" android:layout_width="fill_parent" android:layout_height="match_parent" android:hint="Type something here" /> </LinearLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" app:layout_behavior="@string/appbar_scrolling_view_behavior" tools:context="com.example.notes_2.MainActivity"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:paddingLeft="10sp" android:paddingRight="10sp" android:id="@+id/time" /> <TextView android:id="@+id/content" android:layout_below="@+id/time" android:layout_width="wrap_content" android:layout_height="wrap_content" android:singleLine="true" android:ellipsize="end" android:paddingLeft="10sp" android:paddingRight="10sp" android:paddingTop="15sp" android:paddingBottom="15sp" /> </RelativeLayout>

modify.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:orientation="vertical" > <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@color/colorPrimary" > <Button android:id="@+id/btn_update" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="保存" android:background="@color/colorPrimary" /> <TextClock android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:format12Hour="yyyy年dd月MM日 HH:mm" /> <Button android:id="@+id/btn_back" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="返回" android:background="@color/colorPrimary" /> <Button android:id="@+id/btn_delete" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="删除" android:background="@color/colorPrimary" /> </LinearLayout> <EditText android:id="@+id/et_modify" android:layout_width="fill_parent" android:layout_height="match_parent" /> </LinearLayout>

Content.java

package com.example.notes_2; import android.app.Activity; import android.content.DialogInterface; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; import java.sql.Time; import java.text.SimpleDateFormat; import java.util.Date; public class Content extends Activity implements View.OnClickListener { private Button okButton,cancleButton; private EditText contentWrite; private DBHelper dbHelper; private Cursor cursor; private int _id=0; private Time time; @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.content); SimpleDateFormat formatter=new SimpleDateFormat("yyyy年MM月dd日 HH:mm:ss"); Date curDate = new Date(System.currentTimeMillis()); String string=formatter.format(curDate); Log.e("0",string); init(); } private void init(){ dbHelper=new DBHelper(this); cursor=dbHelper.select(); okButton = (Button) findViewById(R.id.btn_ok); cancleButton = (Button) findViewById(R.id.btn_cancle); contentWrite = (EditText) findViewById(R.id.et_content); okButton.setOnClickListener(this); cancleButton.setOnClickListener(this); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.btn_ok: addData() ; Intent intent = new Intent(this,MainActivity.class); startActivity(intent); finish(); break; case R.id.btn_cancle: Intent intent1 = new Intent(this,MainActivity.class); startActivity(intent1); finish(); break; } } private void addData(){ if (contentWrite.getText().toString().equals("")){ Toast.makeText(Content.this,"内容不能为空",Toast.LENGTH_SHORT).show(); }else{ dbHelper.insert(contentWrite.getText().toString()); cursor.requery(); contentWrite.setText(""); _id=0; } } }

DBHelper.java

package com.example.notes_2; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public class DBHelper extends SQLiteOpenHelper { private final static String DB_NAME="my.db"; private final static int DB_VERSION=1; private final static String TABLE_NAME="info"; private final static String CONTENT="content"; private final static String ID="_id"; SQLiteDatabase database=getWritableDatabase(); public DBHelper(Context context){ super(context,DB_NAME,null,DB_VERSION); } @Override public void onCreate(SQLiteDatabase database){ database.execSQL("create table " + TABLE_NAME + "(" + ID + " integer primary key autoincrement," + CONTENT + " text)"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } public long insert(String text){ ContentValues contentValues=new ContentValues(); contentValues.put("content",text); long row=database.insert(TABLE_NAME,null,contentValues); return row; } public void update(int _id,String text){ ContentValues contentValues=new ContentValues(); contentValues.put("content",text); database.update(TABLE_NAME,contentValues,ID+"=?",new String[]{Integer.toString(_id)}); } public void delete(int _id){ database.delete(TABLE_NAME, ID + "=?", new String[]{Integer.toString(_id)}); } public Cursor select(){ Cursor cursor=database.query(TABLE_NAME,null,null,null,null,null,null); return cursor; } }

MainActivity.java

package com.example.notes_2; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.widget.AdapterView; import android.widget.ListView; import android.widget.SimpleCursorAdapter; public class MainActivity extends AppCompatActivity { private ListView listView; private Cursor cursor; private DBHelper dbHelper; private int _id=0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); dbHelper=new DBHelper(this); cursor=dbHelper.select(); listView=(ListView)findViewById (R.id.listview_title); SimpleCursorAdapter adapter=new SimpleCursorAdapter(this,R.layout.list_item,cursor, new String[]{"content"},new int[]{R.id.content}); listView.setAdapter(adapter); listView.invalidateViews(); listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { cursor.moveToPosition(position); _id=cursor.getInt(0); Intent intent=new Intent(MainActivity.this,Modify.class); intent.putExtra("id",_id); intent.putExtra("data",cursor.getString(1));//getString(1)显示cursor该列的内容 startActivity(intent); finish(); } }); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); fab.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(MainActivity.this,Content.class); startActivity(intent); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } }

Modify.java

package com.example.notes_2; import android.app.Activity; import android.content.Intent; import android.database.Cursor; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class Modify extends Activity implements View.OnClickListener { private EditText et_show; private Button updateButton, deleteButton, backButton; private DBHelper dbHelper; private Cursor cursor; private int id; @Override protected void onCreate(Bundle s) { super.onCreate(s); setContentView(R.layout.modify); init(); } private void init() { et_show = (EditText) findViewById(R.id.et_modify); Intent intent = getIntent(); String data = intent.getStringExtra("data"); id = intent.getIntExtra("id", id); et_show.setText(data); dbHelper = new DBHelper(this); cursor = dbHelper.select(); updateButton = (Button) findViewById(R.id.btn_update); deleteButton = (Button) findViewById(R.id.btn_delete); backButton = (Button) findViewById(R.id.btn_back); updateButton.setOnClickListener(this); deleteButton.setOnClickListener(this); backButton.setOnClickListener(this); } public void updateData() { if (id == 0) { Toast.makeText(Modify.this, "内容不能为空", Toast.LENGTH_SHORT).show(); } else { dbHelper.update(id, et_show.getText().toString()); cursor.requery(); id = 0; } } public void deleteData(){ if (id==0){ Toast.makeText(Modify.this, "内容不能为空", Toast.LENGTH_SHORT).show(); }else{ dbHelper.delete(id); cursor.requery(); id=0; } } @Override public void onClick(View arg0) { switch (arg0.getId()) { case R.id.btn_update: updateData(); Intent intent1 = new Intent(this,MainActivity.class); startActivity(intent1); finish(); break; case R.id.btn_delete: deleteData(); Intent intent = new Intent(this,MainActivity.class); startActivity(intent); finish(); break; case R.id.btn_back: Intent intent2 = new Intent(this,MainActivity.class); startActivity(intent2); finish(); break; } } }