本文实例为大家分享了Android通讯录案例，供大家参考，具体内容如下

实战演练——通讯录

1、功能描述：通过SQLite实现数据库的增删改查

2、技术要点：SQLite的基本操作

3、实现步骤：

① 创建一个类继承SQLiteOpenHelper

② 重写父类构造方法、onCreate()、onUpgrade()

③ 增删改查

4、效果图

5、案例代码

MyHelper.java

package com.example.sqlite;

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

import androidx.annotation.Nullable;

public class MyHelper extends SQLiteOpenHelper {

public MyHelper(@Nullable Context context) {

super(context, "test.db", null, 1);

}

//当数据库第一次创建的时候执行

@Override

public void onCreate(SQLiteDatabase db) {

db.execSQL("CREATE TABLE information(_id INTEGER PRIMARY KEY AUTOINCREMENT ,name VARCHAR(20),phone VARCHAR(20))");

}

@Override

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

}

}

MainActivity.java

package com.example.sqlite;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

private TextView name;

private TextView phone;

private Button btnAdd;

private Button btnDel;

private Button btnUqd;

private Button btnSel;

private String uPhone;

private String uName;

private MyHelper myHelper;

private SQLiteDatabase db;

private TextView show;

private ContentValues contentValues;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

myHelper = new MyHelper(this);

init();

}

private void init() {

show = findViewById(R.id.show);

name = findViewById(R.id.name);

phone = findViewById(R.id.phone);

btnAdd = findViewById(R.id.insert);

btnDel = findViewById(R.id.delete);

btnUqd = findViewById(R.id.update);

btnSel = findViewById(R.id.select);

btnAdd.setOnClickListener(this);

btnDel.setOnClickListener(this);

btnUqd.setOnClickListener(this);

btnSel.setOnClickListener(this);

}

@Override

public void onClick(View v) {

switch (v.getId()) {

case R.id.select:

db = myHelper.getReadableDatabase();

Cursor cursor = db.query("information", null, null, null, null, null, null);

if (cursor.getCount() == 0) {

Toast.makeText(this, "没有数据", Toast.LENGTH_LONG).show();

} else {

cursor.moveToFirst();

show.setText("Name:" + cursor.getString(1) + "Tel:" + cursor.getString(2));

}

while (cursor.moveToNext()) {

show.append("\n" + "Name" + cursor.getString(1) + "Tel" + cursor.getString(2));

}

cursor.close();

db.close();

break;

case R.id.insert:

uName = name.getText().toString();

uPhone = phone.getText().toString();

db = myHelper.getReadableDatabase();

contentValues = new ContentValues();

contentValues.put("name", uName);

contentValues.put("phone", uPhone);

db.insert("information", null, contentValues);

db.close();

break;

case R.id.update:

db = myHelper.getReadableDatabase();

contentValues = new ContentValues();

contentValues.put("phone", uPhone = phone.getText().toString());

db.update("information", contentValues, "name=?", new String[]{name.getText().toString()});

db.close();

break;

case R.id.delete:

db = myHelper.getReadableDatabase();

db.delete("information", null, null);

Toast.makeText(this, "信息已经删除", Toast.LENGTH_LONG).show();

show.setText("");

db.close();

break;

}

}

}

activity_main.xml

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"

tools:context=".MainActivity"

android:background="@drawable/background">

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

>

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal"

>

android:layout_width="160dp"

android:layout_height="120dp"

android:layout_marginTop="50dp"

android:layout_marginLeft="20dp"

android:src="@drawable/expression">

android:layout_width="160dp"

android:layout_height="120dp"

android:layout_marginTop="50dp"

android:layout_marginLeft="20dp"

android:src="@drawable/text">

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal"

android:layout_marginTop="20dp"

android:paddingHorizontal="20dp"

>

android:layout_width="0dp"

android:layout_height="wrap_content"

android:layout_weight="1"

android:text="姓 名 :"

android:textSize="26sp"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent" />

android:id="@+id/name"

android:layout_width="0dp"

android:layout_weight="3"

android:layout_height="wrap_content"

android:hint="请输入姓名"

android:textSize="22sp"

>

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal"

android:layout_marginTop="20dp"

android:paddingHorizontal="20dp"

>

android:layout_width="0dp"

android:layout_height="wrap_content"

android:layout_weight="1"

android:text="电 话 :"

android:textSize="26sp"

app:layout_constraintBottom_toBottomOf="parent"

app:layout_constraintLeft_toLeftOf="parent"

app:layout_constraintRight_toRightOf="parent"

app:layout_constraintTop_toTopOf="parent" />

android:id="@+id/phone"

android:layout_width="0dp"

android:layout_weight="3"

android:layout_height="wrap_content"

android:hint="请输入手机号码"

android:textSize="22sp"

>

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:orientation="horizontal"

android:layout_marginTop="20dp"

android:paddingHorizontal="20dp"

>

android:id="@+id/insert"

android:layout_width="0dp"

android:layout_weight="1"

android:layout_height="wrap_content"

android:text="增加"

android:textSize="26sp"

>

android:id="@+id/select"

android:layout_width="0dp"

android:layout_weight="1"

android:layout_height="wrap_content"

android:text="查询"

android:textSize="26sp"

>

android:id="@+id/update"

android:layout_width="0dp"

android:layout_weight="1"

android:layout_height="wrap_content"

android:text="修改"

android:textSize="26sp"

>

android:id="@+id/delete"

android:layout_width="0dp"

android:layout_weight="1"

android:layout_height="wrap_content"

android:text="删除"

android:textSize="26sp"

>

android:id="@+id/show"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:gravity="center"

android:textSize="18sp"

android:background="#80ffffff"

android:layout_marginHorizontal="20dp"

>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。