Android开发之记账本开发第二天

一、说在前面

昨天完成了对BaseAdapter的学习，今天主要完成前期的准备和计划，并且完成了适配器的配置和测试。今天完成的内容较少，晚上早点睡明天完成数据库的部署和对业务逻辑的初步整理。

二、今天完成的源程序代码

package com.example.daliy;

import android.os.Bundle;

import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private List<CostBean> costBeanList;
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        costBeanList=new ArrayList<>();
        ListView costList=findViewById(R.id.lv_main);
        initCostData();

        costList.setAdapter(new CostAdapter(this,costBeanList));

        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
    }

    private void initCostData() {
        for(int i=0;i<6;i++) {

            CostBean cb=new CostBean();
            cb.costDate="12-12";
            cb.costMoney="50";
            cb.costTitle="heih";
            costBeanList.add(cb);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="80dp">

    <TextView
        android:layout_width="100dp"
        android:layout_marginLeft="10dp"
        android:layout_alignParentLeft="true"
        android:text="CostTitlesdfsdf"
        android:textSize="35sp"
        android:gravity="center"
        android:ellipsize="marquee"
        android:singleLine="true"
        android:id="@+id/tv_costTitle"
        android:layout_height="80dp"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="80dp"
        android:layout_toRightOf="@id/tv_costTitle"
        android:textSize="30dp"
        android:gravity="center"
        android:id="@+id/tv_costDate"
        android:layout_marginLeft="15dp"
        android:text="costDate"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="80dp"
        android:gravity="center"
        android:textSize="30sp"
        android:layout_marginRight="20dp"
        android:layout_alignParentRight="true"
        android:id="@+id/tv_costMoney"
        android:text="30"/>


</RelativeLayout>

package com.example.daliy;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

public class CostAdapter extends BaseAdapter {

    private List<CostBean> mlist;
    private LayoutInflater minflater;
    private Context mcontext;

    public CostAdapter(Context context, List<CostBean> list) {
        mlist = list;
        mcontext = context;
        minflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return mlist.size();
    }

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

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            viewHolder = new ViewHolder();
            convertView = minflater.inflate(R.layout.list_item, null);
            viewHolder.mTvcostTitle = convertView.findViewById(R.id.tv_costTitle);
            viewHolder.mTvcostMoney = convertView.findViewById(R.id.tv_costMoney);
            viewHolder.mTvcostDate = convertView.findViewById(R.id.tv_costDate);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }
        CostBean bean = mlist.get(position);
        viewHolder.mTvcostTitle.setText(bean.costTitle);
        viewHolder.mTvcostMoney.setText(bean.costMoney);
        viewHolder.mTvcostDate.setText(bean.costDate);
        return convertView;
    }

    private static class ViewHolder {
        public TextView mTvcostTitle;
        public TextView mTvcostDate;
        public TextView mTvcostMoney;
    }


}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    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"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context=".MainActivity"
    tools:showIn="@layout/activity_main">

    <ListView
        android:id="@+id/lv_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

三、效果

item封装的效果，用来显示花费的备注，日期和钱

 编写完适配器之后的测试结果。

四、心得体会

发现自己的学习效率比较低，看视频总得看好几遍才能明白讲师的意思，所以明天需要作出一些改变了！