黑名单增删改

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <LinearLayout        android:layout_width="match_parent"        android:layout_height="0dp"        android:orientation="vertical"         android:layout_weight="1"        android:gravity="center">        <ListView            android:id="@+id/lv_main_blacks"            android:layout_width="match_parent"            android:layout_height="match_parent"             android:visibility="gone">        </ListView>             <TextView            android:gravity="center"        android:id="@+id/tv_main_empty"        android:layout_width="fill_parent"        android:layout_height="match_parent"        android:text="还没有一个黑名单"         android:textSize="20dp"        android:visibility="visible"/>            </LinearLayout>       <LinearLayout             android:layout_width="match_parent"             android:layout_height="wrap_content"             android:orientation="horizontal"              android:background="#999999">        <EditText            android:id="@+id/et_main_number"            android:layout_width="0dp"            android:layout_height="wrap_content"            android:layout_weight="1">        </EditText>        <Button            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="添 加"             android:onClick="addBlack"/>  </LinearLayout>    </LinearLayout>

Black.java（只列出属性即可，其他省略）

private int id;private String number;

DBHelper.java

package com.example.heimingdan;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;public class DBHelper extends SQLiteOpenHelper {/** * 数据库名字--数据库表名字 */private static String DBNAME = "wyf.db";public static String TABLE_NAME = "black";/** * 初始化创建数据库 */public DBHelper(Context context) {super(context, DBNAME, null, 1);}/** * 创建数据库表 */@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL("create table black(_id integer primary key autoincrement,number)");}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}}

Dao.java

package com.example.heimingdan;import java.util.ArrayList;import java.util.List;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;public class Dao {private DBHelper dbHelper;/* *dao一创建就初始化dbhelper  */public Dao(Context context){dbHelper = new DBHelper(context);}/* * 添加对象 */public void add(Black black){SQLiteDatabase database = dbHelper.getReadableDatabase();//准备数据ContentValues values = new ContentValues();values.put("number", black.getNumber());//执行插入操作long id = database.insert(DBHelper.TABLE_NAME, null, values);//关闭资源database.close();}/* * 删除 */public void deleteById(String id) {SQLiteDatabase database = dbHelper.getReadableDatabase();int deleteCount = database.delete(DBHelper.TABLE_NAME, "_id=?", new String[]{id});database.close();}/* * 更新 */public void update(Black black) {SQLiteDatabase database = dbHelper.getReadableDatabase();//准备数据ContentValues values = new ContentValues();values.put("number", black.getNumber());int updateCount = database.update(DBHelper.TABLE_NAME, values, "_id=?", new String[]{black.getId()+""});database.close();}/* * 查询 */public List<Black> getAll() {List<Black> list = new ArrayList<Black>();SQLiteDatabase database = dbHelper.getReadableDatabase();Cursor cursor = database.query(DBHelper.TABLE_NAME, null, null, null, null, null, null);while(cursor.moveToNext()) {int id = cursor.getInt(0);String number = cursor.getString(1);Black blackNumber = new Black(id, number);list.add(blackNumber);}cursor.close();database.close();return list;}}

MainActivity.java

package com.example.heimingdan;import java.util.List;import android.app.Activity;import android.app.AlertDialog;import android.content.DialogInterface;import android.os.Bundle;import android.view.ContextMenu;import android.view.MenuItem;import android.view.View;import android.view.ViewGroup;import android.view.ContextMenu.ContextMenuInfo;import android.widget.AdapterView.AdapterContextMenuInfo;import android.widget.BaseAdapter;import android.widget.EditText;import android.widget.ListView;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity {private ListView lv_main_blacks;private TextView tv_main_empty;private EditText et_main_number;// 用来对黑名单的增删改以及获取 黑名单集合private Dao dao;private List<Black> data;// 设置存放黑名单的适配器private Myadapter adapter;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);// 获取number视图et_main_number = (EditText) findViewById(R.id.et_main_number);// 获取listview视图lv_main_blacks = (ListView) findViewById(R.id.lv_main_blacks);// 获取textview视图tv_main_empty = (TextView) findViewById(R.id.tv_main_empty);dao = new Dao(this);// 获取所有的黑名单条目data = dao.getAll();// 界面加载时候，如果有黑名单就显示出来if (data != null && data.size() > 0) {// 隐藏textviewtv_main_empty.setVisibility(View.GONE);// 显示列表lv_main_blacks.setVisibility(View.VISIBLE);adapter = new Myadapter();// listview设置适配器lv_main_blacks.setAdapter(adapter);}// 添加listview上下菜单的监听--本类已经实现了接口，需要重写某方法lv_main_blacks.setOnCreateContextMenuListener(this);}// 产生上下文列表@Overridepublic void onCreateContextMenu(ContextMenu menu, View v,ContextMenuInfo menuInfo) {menu.add(0, 1, 0, "更新");menu.add(0, 2, 0, "删除");super.onCreateContextMenu(menu, v, menuInfo);}// 对上下文列表item设置方法@Overridepublic boolean onContextItemSelected(MenuItem item) {// ContextMenuInfo是一个接口，需要实现类AdapterContextMenuInfo menuInfo = (AdapterContextMenuInfo) item.getMenuInfo();// 选择的view的下标int location = menuInfo.position;switch (item.getItemId()) {case 1:showUpdateDialog(location);break;case 2:Black black = data.get(location);// 删除表中的数据dao.deleteById(black.getId() + "");// 删除list中的数据data.remove(location);// 更新界面adapter.notifyDataSetChanged();break;default:break;}return super.onContextItemSelected(item);}/** * 更新黑名单号码的方法 */private void showUpdateDialog(int location) {final Black black = data.get(location);// 需要更新的条目的numberString number = black.getNumber();final EditText editText = new EditText(this);new AlertDialog.Builder(this).setTitle("更新：" + number).setView(editText).setPositiveButton("确定", new DialogInterface.OnClickListener() {@Overridepublic void onClick(DialogInterface dialog, int which) {String newNumber = editText.getText().toString();black.setNumber(newNumber);dao.update(black);// 更新界面adapter.notifyDataSetChanged();}}).setNegativeButton("取消", null).show();}// 添加黑名单public void addBlack(View view) {// 读取数据String number = et_main_number.getText().toString();// 准备对象Black black = new Black();black.setNumber(number);// 保存对象dao.add(black);Toast.makeText(this, "保存成功", 0).show();// 更新黑名单列表data = dao.getAll();// 通知更新adapter.notifyDataSetChanged();}// 自定义适配器private class Myadapter extends BaseAdapter {@Overridepublic int getCount() {return data.size();}@Overridepublic Object getItem(int position) {return data.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (convertView == null) {// 动态加载布局convertView = View.inflate(MainActivity.this,android.R.layout.simple_list_item_1, null);}// 得到当前的记录Black black = data.get(position);// 得到布局文件的视图对象TextView tv = (TextView) convertView.findViewById(android.R.id.text1);// 将记录设置到对应的位置上去tv.setText(black.getNumber());return convertView;}}}