GreenDao配置以及使用

在App工程build最上面添加

apply plugin: 'org.greenrobot.greendao'

然后在app工程build里在buildTypes里面配置greendao，，切记daoPackage一定要写自己工程的目录

 greendao {
        schemaVersion 1
        daoPackage 'com.example.greendao_lianxi.gen'
        targetGenDir 'src/main/java'
    }

然后添加greendao依赖

compile'org.greenrobot:greendao:3.2.2'

然后在项目build里buildscript下配置，配置完记得编译才有下面的注解

mavenCentral()

看好再添加 
classpath 'org.greenrobot:greendao-gradle-plugin:3.2.2'

自己写实体类，定义自己需要的参数，记得注解

package com.example.greendao_lianxi;

import org.greenrobot.greendao.annotation.Entity;
import org.greenrobot.greendao.annotation.Id;
import org.greenrobot.greendao.annotation.Property;

/**
 * Created by Administrator on 2017/12/1.
 */
@Entity
public class Use {
   @Id(autoincrement=true)
    private long id;
    @Property(nameInDb = "name")
    private String name;

@Transient//这个注解意思为这个属性不会保存到数据库为属性 在数据库中不对这个属性进行操作

privateint tempUsageCount;// not persisted

 }

然后点击这个按钮会自动生成三个类

再定义一个类通过单例创建数据库

package com.example.greendao_lianxi;

import android.app.Application;
import android.database.sqlite.SQLiteDatabase;

import com.example.greendao_lianxi.gen.DaoMaster;
import com.example.greendao_lianxi.gen.DaoSession;

/**
 * Created by Administrator on 2017/12/1.
 */

public class Api extends Application{
    //配置GreenDao
    private static Api  myApi;
    private DaoSession daoSession;

    @Override
    public void onCreate() {
        super.onCreate();
        myApi = this;
        setDb();
    }



    //单例模式
   public static Api getmyapi(){
        return myApi;
    }

    private void setDb() {
        //创建数据库名
        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(this, "bw,db", null);
        //读取数据库
        SQLiteDatabase database = helper.getWritableDatabase();
        //
        DaoMaster daoMaster = new DaoMaster(database);
        //放入用户信息DaoSession
        daoSession = daoMaster.newSession();

    }
    //返回daoSession
    public DaoSession getDaoSession(){
        return daoSession;
    }
}

然后在MainActivity里写增删改查方法

package com.example.greendao_lianxi1;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.example.greendao_lianxi1.gen.BeanDao;
import com.example.greendao_lianxi1.gen.DaoSession;

import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    private EditText et_name;
    private EditText et_xiu;
    private BeanDao beanDao;
    private TextView tv;
 

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button bt_tian =  findViewById(R.id.bt_tian);
        Button bt_shan =  findViewById(R.id.bt_shan);
        Button bt_gai =  findViewById(R.id.bt_gai);
        Button bt_cha =  findViewById(R.id.bt_cha);
        tv = findViewById(R.id.tv);
        et_name = findViewById(R.id.et_name);
        et_xiu = findViewById(R.id.et_xiu);
        bt_tian.setOnClickListener(this);
        bt_shan.setOnClickListener(this);
        bt_gai.setOnClickListener(this);
        bt_cha.setOnClickListener(this);

        //获取MyGreenDao_Api单例里面返回的方法
        DaoSession daoSession = MyGreenDao_Api.getMyGreenDao_api().getDaoSession();
        beanDao = daoSession.getBeanDao();

    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            //添加
            case  R.id.bt_tian:
                    Bean bean = new Bean(null, et_name.getText().toString().trim());

                    //或者这样添加id
                    Bean bean = new Bean(System.currentTimeMillis(),et_name.getText().toString.trim()); 

                   //添加方法
                    beanDao.insert(bean);
                Toast.makeText(this, "添加成功", Toast.LENGTH_SHORT).show();
                break;

            //删除
            case  R.id.bt_shan:
                //查询
                Bean shanchu_id = beanDao.load(Long.valueOf(1));
                //删除
                beanDao.delete(shanchu_id);
                Toast.makeText(this, "删除成功", Toast.LENGTH_SHORT).show();
                break;
                //修改
            case  R.id.bt_gai:
                //查找指定id
                Bean xiugai_id = beanDao.load(Long.valueOf(2));
                //输入修改内容
                xiugai_id.setName(et_xiu.getText().toString().trim());
                //修改方法
                beanDao.update(xiugai_id);
                Toast.makeText(this, "修改成功", Toast.LENGTH_SHORT).show();
                break;

            //查找
            case  R.id.bt_cha:
                //  load查询单个
                //Bean load = beanDao.load(Long.valueOf(1));
                //  loadAll查询全部
                List<Bean> list = beanDao.loadAll();
                String s="";
                for (int i = 0; i < list.size(); i++) {
                    s+=list.get(i).getName()+"/n";
                }
                tv.setText(s);

                break;
        }
    }
}