家庭记账本第一次

package com.example.jizhangben;

import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity implements View.OnClickListener  {
    private CostDB mCostDB;
    private CostListAdapter mAdapter;
    private SQLiteDatabase dbReader;
    private ListView costList;
    private Intent i;
    private Button bt_shouru,bt_zhichu;

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

        initCost();

    }
    private void initCost() {
        mCostDB=new CostDB(this);
        bt_shouru = (Button)this.findViewById(R.id.fabt_shouru);
        bt_zhichu = (Button)this.findViewById(R.id.fabt_zhichu);
        costList = (ListView)this.findViewById(R.id.lv_list);
        dbReader = mCostDB.getReadableDatabase();
    }
    public void selectDB(){
        Cursor cursor = dbReader.query(CostDB.TABLE_NAME,null,null,null,null,null,null);
        mAdapter = new CostListAdapter(this,cursor);
        costList.setAdapter(mAdapter);
    }

    @Override
    protected void onResume() {
        super.onResume();
        selectDB();
    }

    @Override
    public void onClick(View v) {
        i=new Intent(this,addcost.class);
        startActivity(i);
    }
}