GreenDao单个点击添加到数据库，并查询展示

最新推荐文章于 2021-05-27 13:04:31 发布

原创最新推荐文章于 2021-05-27 13:04:31 发布 · 318 阅读

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本文介绍了如何使用GreenDao库在Android应用中实现单个数据的添加到数据库操作，并详细讲解了查询及展示数据的步骤，包括在工具类中编写数据库操作，确保在App级别进行配置，以及在适配器中添加点击事件来显示数据。

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先把GreenDao数据设置完成，然后再工具类里添加操作

 public void init(Context context){
        DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(context, "result");
        SQLiteDatabase db = helper.getWritableDatabase();
        DaoMaster daoMaster = new DaoMaster(db);
        dao = daoMaster.newSession().getResultBeanDao();
    }
    //添加
    public void add(ResultBean bean){
        List<ResultBean> list = dao.loadAll();
        for (int i = 0; i <list.size() ; i++) {
            ResultBean bean1 = list.get(i);
            if(bean.getCommodityId() == bean1.getCommodityId()){
                dao.delete(bean1);
            }
        }
        dao.insert(bean);
    }
    //查询全部
    public List<ResultBean> loadAll(){
        List<ResultBean> listTemp = new ArrayList<>();
        List<ResultBean> list = dao.loadAll();
        for (int i = 0; i < list.size(); i++) {
            ResultBean bean = list.get(i);
            listTemp.add(0,bean);
        }
        return listTemp;
    }

工具类写完之后，切记不要忘了在App里适配

RetrofitUtils.getmInstance().init(this);

App设置完后，在适配器里添加条目点击事件

 //条目点击事件
        viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                RetrofitUtils.getmInstance().add(list.get(i));
            }
        });

最后在相应的页面展示数据

package jiaoyibo.bawei.com.molizhoukao01.fragment;

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.GridLayoutManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

import com.jcodecraeer.xrecyclerview.XRecyclerView;

import java.util.List;

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;
import butterknife.Unbinder;
import jiaoyibo.bawei.com.molizhoukao01.R;
import jiaoyibo.bawei.com.molizhoukao01.adapter.UserAdapter;
import jiaoyibo.bawei.com.molizhoukao01.bean.ResultBean;
import jiaoyibo.bawei.com.molizhoukao01.net.RetrofitUtils;

/**
 * <p>文件描述：<p>
 * <p>作者：JYB<p>
 * <p>创建时间：2019/4/14<p>
 * <p>更改时间：2019/4/14<p>
 * <p>版本号：1<p>
 */
public class FragmentTwo extends Fragment {
    @BindView(R.id.button_01)
    Button mButton01;
    @BindView(R.id.xrec1)
    XRecyclerView mXrec1;
    private View view;
    private Unbinder unbinder;
    private UserAdapter userAdapter;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_02, container, false);
        unbinder = ButterKnife.bind(this, view);
        mXrec1.setLayoutManager(new GridLayoutManager(getContext(),2));
        userAdapter = new UserAdapter(getContext());
        mXrec1.setAdapter(userAdapter);
        return view;
    }

    @OnClick(R.id.button_01)
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.button_01:
                List<ResultBean> list = RetrofitUtils.getmInstance().loadAll();
                userAdapter.setList(list);
                break;
        }
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        unbinder.unbind();
    }
}