通讯录作业

package com.example.wang.tongxunlu;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

import com.example.wang.tongxunlu.com.wang.tongxunlu.orm.TongXunLu;
import com.example.wang.tongxunlu.com.wang.tongxunlu.orm.TongXunLuDAO;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    ListView lv_1;

    //数据访问对象
    TongXunLuDAO tongXunLuDAO=new TongXunLuDAO(this);

    //数据集合
    ArrayList<TongXunLu> arrayList;

    MyAdapter myAdapter;

    int index;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        lv_1=(ListView)findViewById(R.id.lv_1);

        arrayList=tongXunLuDAO.getAll();

        myAdapter=new MyAdapter();

        lv_1.setAdapter(myAdapter);

        lv_1.setOnCreateContextMenuListener(this);
    }

    //增加
    public void bt_OnClick(View v)
    {
       final View view= View.inflate(this, R.layout.tongxunlu_activity, null);

        AlertDialog alertDialog=new AlertDialog.Builder(this)
                .setTitle("添加联系人信息")
                .setView(view)
                .setPositiveButton("保存", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        EditText et_name=(EditText)view.findViewById(R.id.et_name);
                        EditText et_phone=(EditText)view.findViewById(R.id.et_phone);

                       TongXunLu tongXunLu=new TongXunLu(et_name.getText().toString(),
                               et_phone.getText().toString());

                        long l=tongXunLuDAO.insert(tongXunLu);

                        if (l>0)
                        {
                            Toast.makeText(MainActivity.this, "添加成功", Toast.LENGTH_SHORT).show();
                        }
                        else
                        {
                            Toast.makeText(MainActivity.this, "添加失败", Toast.LENGTH_SHORT).show();
                        }

                        arrayList.add(0, tongXunLu);

                        myAdapter.notifyDataSetChanged();

                    }
                })
                .setNegativeButton("取消",null)
                .show();
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);

        menu.add(0, 1, 1, "修改");
        menu.add(0,2,2,"删除");

        AdapterView.AdapterContextMenuInfo m=(AdapterView.AdapterContextMenuInfo)menuInfo;

        index=m.position;
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {

        Log.e("TAG","index="+index);
        switch (item.getItemId())
        {
            case 1:
                //修改
                View view= View.inflate(this, R.layout.tongxunlu_activity, null);

                final EditText et_name=(EditText)view.findViewById(R.id.et_name);
                et_name.setText(arrayList.get(index).getName());

                final EditText et_phone=(EditText)view.findViewById(R.id.et_phone);
                et_phone.setText(arrayList.get(index).getPhone_number());

                new AlertDialog.Builder(this)
                        .setTitle("修改联系人信息")
                        .setView(view)
                        .setPositiveButton("修改", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {

                                TongXunLu tongxunlu = arrayList.get(index);

                                tongxunlu.setName(et_name.getText().toString());
                                tongxunlu.setPhone_number(et_phone.getText().toString());

                                if (tongXunLuDAO.updata(tongxunlu) > 0) {
                                    Toast.makeText(MainActivity.this, "修改成功", Toast.LENGTH_SHORT).show();
                                } else {
                                    Toast.makeText(MainActivity.this, "修改失败", Toast.LENGTH_SHORT).show();
                                }
                                //刷新列表
                                myAdapter.notifyDataSetChanged();
                            }
                        })
                        .setNegativeButton("取消", null)
                        .show();

                break;

            case 2:

                //删除
                new  AlertDialog.Builder(this)
                        .setTitle("确定要删除？")
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {

                                //删除
                                if ( tongXunLuDAO.delete(arrayList.get(index).getId())>0)
                                {
                                    Toast.makeText(MainActivity.this, "删除成功", Toast.LENGTH_SHORT).show();

                                    //更新List
                                    arrayList.remove(index);

                                    //刷新列表
                                    myAdapter.notifyDataSetChanged();
                                }
                                else
                                {
                                    Toast.makeText(MainActivity.this, "删除失败", Toast.LENGTH_SHORT).show();
                                }

                            }
                        })
                        .setNegativeButton("取消",null)
                        .show();

                break;

        }

        return super.onContextItemSelected(item);
    }

    class MyAdapter extends BaseAdapter
    {
        @Override
        public int getCount() {
            return arrayList.size();
        }

        @Override
        public Object getItem(int position) {
            return arrayList.get(position);
        }

        @Override
        public long getItemId(int position) {
            return arrayList.get(position).getId();
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            TongXunLu tongXunLu=arrayList.get(position);

            if (convertView==null)
            {
                convertView=View.inflate(MainActivity.this,R.layout.tongxunlu_activity,null);
            }

            EditText editText=(EditText)convertView.findViewById(R.id.et_name);

            editText.setText(tongXunLu.getName());

            EditText editText1=(EditText)convertView.findViewById(R.id.et_phone);

            editText1.setText(tongXunLu.getPhone_number());

            return convertView;
        }
    }
}

MainActivity

package com.example.wang.tongxunlu.com.wang.tongxunlu.orm;

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;

//数据库操作类
public class TongXunLuDAO {

    private  DBHelper dh;

    private  final String  TABLENAME="t_tongxunl";

    public TongXunLuDAO(Context context)
    {
        // this.context=context;

        dh=new DBHelper(context);
    }

    //增
    //传入参数:实体类的实例
    public long insert(TongXunLu tongxunlu)
    {
        long rtn=0;
        //连接数据库
        SQLiteDatabase sd=dh.getWritableDatabase();

        ContentValues cv=new ContentValues();

        cv.put("name",tongxunlu.getName());

        cv.put("phone_number",tongxunlu.getPhone_number());

        rtn=sd.insert(TABLENAME,null,cv);

        sd.close();
        return rtn;
    }

    //删
    public int delete(long id)
    {
        int rtn=0;

        SQLiteDatabase sd=dh.getWritableDatabase();

        rtn=sd.delete(TABLENAME,"_id=?",new String[]{id+""});

        sd.close();
        return rtn;
    }

    //改
    public int updata(TongXunLu tongxunlu)
    {
        int rtn=0;

        SQLiteDatabase sd=dh.getWritableDatabase();

        ContentValues cv=new ContentValues();

        cv.put("name",tongxunlu.getName());

        cv.put("phone_number",tongxunlu.getPhone_number());

        rtn=sd.update(TABLENAME,cv,"_id=?",new String[]{tongxunlu.getId()+""});

        Log.e("TAG","rtn="+rtn);

        sd.close();
        return  rtn;
    }
    //查
    //返回查询结果
    public ArrayList<TongXunLu> getAll()
    {
        ArrayList<TongXunLu>  tongxunlus=new ArrayList<>();

        //连接数据库
        SQLiteDatabase sd=dh.getWritableDatabase();

        //查询之后得到游标结果集
        Cursor cursor=sd.query(TABLENAME, null, null, null, null, null, "_id desc");

        //遍历结果集
        while (cursor.moveToNext())
        {
            //1.把数据转成实体类的实例
            TongXunLu bl=new TongXunLu(cursor.getLong(0),cursor.getString(1),cursor.getString(2));

            tongxunlus.add(bl);

        }

        cursor.close();

        sd.close();
        return tongxunlus;
    }

}

TongXunLuDAO

package com.example.wang.tongxunlu.com.wang.tongxunlu.orm;

public class TongXunLu {

    private long id;
    private String name;
    private  String phone_number;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getPhone_number() {
        return phone_number;
    }

    public void setPhone_number(String phone_number) {
        this.phone_number = phone_number;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public TongXunLu(long id, String name, String phone_number) {
        this.id = id;
        this.phone_number = phone_number;
        this.name = name;
    }

    public TongXunLu(String name, String phone_number) {
        this.phone_number = phone_number;
        this.name = name;
    }
}

TongXunLu

package com.example.wang.tongxunlu.com.wang.tongxunlu.orm;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DBHelper extends SQLiteOpenHelper {

    @Override
    public void onCreate(SQLiteDatabase db) {

        String sql= "CREATE TABLE t_tongxunl (_id  INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL," +
                        "name  TEXT,phone_number  INTEGER)";
        db.execSQL(sql);

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }

    public DBHelper(Context context) {
        super(context, "TongXunl.db", null, 1);
    }
}

DBHelper

<?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="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.wang.tongxunlu.MainActivity"
    android:orientation="vertical">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:id="@+id/lv_1"
        android:layout_weight="1"></ListView>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="添加联系人"
        android:id="@+id/bt_1"
        android:onClick="bt_OnClick"/>

</LinearLayout>

activity_main

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="姓名:"
            android:id="@+id/tv_name"/>
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/et_name"/>
    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="电话:"
            android:id="@+id/tv_phone"/>
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/et_phone"/>
    </LinearLayout>

</LinearLayout>

tongxunlu_activity