Android课程---添加黑名单的练习（课堂讲解）
DBHelper.java
package com.hanqi.test3; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; /** * Created by Administrator on 2016/4/15. */ public class DBHelper extends SQLiteOpenHelper { public DBHelper(Context context) { super(context, "blacklist.db",null, 1); } @Override public void onCreate(SQLiteDatabase db) { db.execSQL("create table black_number (_id integer primary key autoincrement,phone_number varchar)"); Log.e("TAG","onCreate"); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } }
BlackNumber.java
package com.hanqi.test3; /** * Created by Administrator on 2016/4/15. */ public class BlackNumber { private long id; private String phoneNumber; public BlackNumber(long id, String phoneNumber) { this.id = id; this.phoneNumber = phoneNumber; } public BlackNumber() { } public long getId() { return id; } public void setId(long id) { this.id = id; } public String getPhoneNumber() { return phoneNumber; } public void setPhoneNumber(String phoneNumber) { this.phoneNumber = phoneNumber; } public BlackNumber(String phoneNumber) { this.phoneNumber = phoneNumber; } @Override public String toString() { return "BlackNumber{" + "id=" + id + ", phoneNumber='" + phoneNumber + '\'' + '}'; } }
TestActivity1.java
package com.hanqi.test3; import android.app.AlertDialog; import android.content.DialogInterface; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.text.InputType; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.EditText; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import java.util.List; public class TestActivity1 extends AppCompatActivity { private ListView lv_1; private List<BlackNumber> data; private BlackListAdapter dla; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_test1); lv_1 = (ListView)findViewById(R.id.lv_1); //获取数据集合 BlackNumberDAO bd = new BlackNumberDAO(this); data = bd.getAll(); dla = new BlackListAdapter(); //设置适配器 lv_1.setAdapter(dla); } //实现列表的适配器 class BlackListAdapter extends BaseAdapter { @Override public int getCount() { return data.size(); } @Override public Object getItem(int position) { return data.get(position); } @Override public long getItemId(int position) { return data.get(position).getId(); } @Override public View getView(int position, View convertView, ViewGroup parent) { //position:要显示的那条记录 //判断可复用的视图是否为空 if (convertView == null) { //获取视图 convertView = View.inflate(TestActivity1.this,android.R.layout.simple_list_item_1,null); } //给视图绑定数据 TextView tv =(TextView)convertView.findViewById(android.R.id.text1); tv.setText(data.get(position).getPhoneNumber()); return convertView; } } public void bt1_OnClick(View v) { final EditText editText = new EditText(this); editText.setHint("请输入电话号码"); editText.setInputType(InputType.TYPE_CLASS_PHONE); //editText.setLayoutParams(new DrawerLayout.LayoutParams()); //editText.setInputType(); //构造自定义对话框 new AlertDialog.Builder(this) .setTitle("添加黑名单") .setView(editText) .setPositiveButton("添加", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { //构造实体类 BlackNumber blacknumber = new BlackNumber(editText.getText().toString()); //调用数据库操作类DAO，保存数据 BlackNumberDAO blackNumberDAO = new BlackNumberDAO(TestActivity1.this); blackNumberDAO.insert(blacknumber); data.add(blacknumber); //通知刷新 dla.notifyDataSetChanged(); Toast.makeText(TestActivity1.this, "数据保存成功", Toast.LENGTH_SHORT).show(); } }) .setNeutralButton("取消",null) .show(); } }
BlackNumberDAO.java
package com.hanqi.test3; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.util.Log; import java.util.ArrayList; import java.util.List; /** * Created by Administrator on 2016/4/15. */ public class BlackNumberDAO { //定义成成员变量 private DBHelper dbHelper; public BlackNumberDAO(Context context) { //初始化工具类 dbHelper = new DBHelper(context); } //增 public void insert(BlackNumber blackNumber) { //获取数据库连接 SQLiteDatabase sd = dbHelper.getWritableDatabase(); //要添加数据的键值对集合 ContentValues contentValues = new ContentValues(); contentValues.put("phone_number",blackNumber.getPhoneNumber()); //数据添加 contentValues：集合存了键值对 sd.insert("black_number",null,contentValues); //关闭数据库 sd.close(); Log.e("TAG","添加数据成功"); } //删 public void delete(long id) { } //改 public void update(BlackNumber blackNumber) { } //查 //用List（List里面装的是实体类的实例）返回数据 public List<BlackNumber> getAll() { List<BlackNumber> rtn = new ArrayList<BlackNumber>(); // ArrayList:实现类 List：接口 //获取数据库连接 SQLiteDatabase sd = dbHelper.getWritableDatabase(); //查询返回游标 Cursor cursor = sd.query("black_number", null, null, null, null, null, null); //移动游标,获取数据 while (cursor.moveToNext()) { //构造实体类的实例,放入List rtn.add(new BlackNumber(cursor.getLong(0),cursor.getString(1))); } Log.e("TAG","数据数量"+cursor.getCount()); sd.close(); return rtn; } }
activity_test1.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="16dp" android:paddingLeft="16dp" android:paddingTop="16dp" android:paddingRight="16dp" tools:context="com.hanqi.test3.TestActivity1" android:orientation="vertical"> <ListView android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:id="@+id/lv_1"></ListView> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:text="添加" android:onClick="bt1_OnClick"/> </LinearLayout>
效果图：
