Android开发实战——记账本（3）

开发日志（3）——适配器

昨天将bean类还有DatabaseHelper类写完。为了在MainActivity中调用，将数据保存到数据库中并显示出来。所以要先编写适配器CostListAdapter

CostListAdapter

package com.example.firstapplication;

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 CostListAdapter extends BaseAdapter {
    private List<CostBean> mList;
    private Context mContext;
    private LayoutInflater mLayoutInflater;

    public CostListAdapter(Context context,List<CostBean> list){
        mContext = context;
        mList = list;
        mLayoutInflater = 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 = mLayoutInflater.inflate(R.layout.list_item,null);
            viewHolder.mTvCostTitle = (TextView) convertView.findViewById(R.id.tv_title);
            viewHolder.mTvCostDate =(TextView) convertView.findViewById(R.id.tv_date);
            viewHolder.mTvCostMoney = (TextView) convertView.findViewById(R.id.tv_cost);
            convertView.setTag(viewHolder);
        } else{
            viewHolder = (ViewHolder) convertView.getTag();
        }
        CostBean bean = mList.get(position);
        viewHolder.mTvCostTitle.setText(bean.costTitle);
        viewHolder.mTvCostDate.setText(bean.costDate);
        viewHolder.mTvCostMoney.setText(bean.costMoney);
        return convertView;
    }

    private static class ViewHolder{
        public TextView mTvCostTitle;
        public TextView mTvCostDate;
        public TextView mTvCostMoney;

    }
}

然后在MainActivity中写一个方法生成数据，并在模拟器中显示出来

明天打算写一下MainActivity中的一些方法，让他实现更多的功能