Android 学习--ListView 的使用(四)

基于BaseAdapter 实现ListView

注意扩展BaseAdapter 需要重写以下四个方法

getCount();

getItem();

getItemId();

getView();

程序清单

package xiaocool.net.listviewtest;

import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

   private ListView list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listview2);
        list=(ListView)this.findViewById(R.id.list1);
        /*//定义一个数组
        String arr[]={"校酷网络1","校酷网络2","校酷网络3","校酷网络4","校酷网络5"};
        //将数组包装成ArrayAdapter
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.array_item,R.id.textView,arr);
        list.setAdapter(adapter);*/
        BaseAdapter adapter=new BaseAdapter() {
            //返回总的列表项数
            @Override
            public int getCount() {
                return 20;
            }

            @Override
            public Object getItem(int position) {
                return null;
            }
          //返回列表项的id
            @Override
            public long getItemId(int position) {
                return 0;
            }
           //返回每个具体item的样子
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
               //创建一个LinearLayout，并向其中添加两个控件
                LinearLayout layout=new LinearLayout(MainActivity.this);
                layout.setOrientation(0);
                ImageView imageView=new ImageView(MainActivity.this);
                imageView.setImageResource(R.drawable.syudio);
                TextView textView=new TextView(MainActivity.this);
                textView.setText("第"+(position+1)+"项");
                textView.setTextColor(Color.BLUE);
                textView.setTextSize(20);
                layout.addView(imageView);
                layout.addView(textView);

                return layout;
            }
        };
        list.setAdapter(adapter);
    }

}