Android之ListView优化

import java.util.List;

import com.example.contentprovider.R;
import com.example.entity.ImagePath;
import com.example.util.Util;

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

public class MyBaseAdapter extends BaseAdapter {
    private List<ImagePath> imagePaths;
    Context context;
    
    public MyBaseAdapter(List<ImagePath> list, Context context) {
        super();
        this.imagePaths = list;
        this.context = context;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return imagePaths.size();
    }

    @Override
    public Object getItem(int arg0) {
        // TODO Auto-generated method stub
        return imagePaths.get(arg0);
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return arg0;
    }

    @Override
    public View getView(int arg0, View arg1, ViewGroup arg2) {
        MyView myView = null;
        View view ;
        //arg1 如果为null则执行该代码；该if判断的作用是优化List：如果arg1为null的时候获取布局该布局会缓存在arg1中，创建myView对象
        //将myView对象存放在view中！当arg1不为空时取出view中的myView对象和缓存中的view
        if(arg1 == null){
            //实例化MyView对象
            myView = new MyView();
            //获取LayoutInflater对象
            LayoutInflater inflater = LayoutInflater.from(context);
            //通过inflater获取ListView中的item的布局
            view = inflater.inflate(R.layout.mybaseadapter,null);
            //获取item布局的组件
            myView.imageView = (ImageView) view.findViewById(R.id.id_image);
            myView.textName = (TextView) view.findViewById(R.id.id_textName);
            myView.textNum = (TextView) view.findViewById(R.id.id_textNum);
            //将myView对象存进view中
            view.setTag(myView);
        }else{
            //如果arg1不为null，将arg1赋给view
            view = arg1;
            //将存放在view中的MyView对象取出来
            myView = (MyView) view.getTag();
        }
        myView.textName.setText(imagePaths.get(arg0).getPakagePath());
        myView.textNum.setText("共"+imagePaths.get(arg0).getListPth().size()+"张");
        myView.imageView.setImageBitmap(Util.getBitmapByPath(imagePaths.get(arg0).getListPth().get(0),86,86));
        return view;
    }

}
    class MyView{
        TextView textName;
        TextView textNum;
        ImageView imageView;
    }

才接触android，在慢慢的自学！后续会更新