Android學習——ListView使用（四）

基於BaseAdapter的ListView

在創建一個BaseAdapter對象的過程中，擴展該對象需要重寫以下四個方法

1、getCount（）

2、getltem(int position)

3、getltemID(int position)

4、getView(int position, View convertView)

程序清單1

MainActivity.java

package xiaocool.net.see;
        import android.app.Activity;
        import android.graphics.Color;
        import android.os.Bundle;
       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 Activity {
    private ListView list;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        list=(ListView)this.findViewById(R.id.list1);
        /*//定義一個數組
        String arr[]={};
        //將數組包裝成ArrayAdapter
        ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,R.layout.array_item,R.id.textView,arr);
        list.setAdapter(adapter);*/
        BaseAdapter adapter=new BaseAdapter() {
            //返回總的列表項數
            @Override
            public int getCount() {
                return 20;
            }
            @Override
            public Object getItem(int position) {
                return null;
            }
            //返回列表項的id
            @Override
            public long getItemId(int position) {
               return 0;
            }
            //返回每個具體item的樣子
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {

                //創建一個LinearLayout，並向其中添加兩個控件
                LinearLayout layout=new LinearLayout(MainActivity.this);
                layout.setOrientation(0);
                ImageView imageView=new ImageView(MainActivity.this);
                imageView.setImageResource(R.drawable.touxiang);
                TextView textView=new TextView(MainActivity.this);
                textView.setText("第"+(position+1)+"項");
                textView.setTextColor(Color.BLUE);
                textView.setTextSize(20);
                layout.addView(imageView);
                layout.addView(textView);
                return layout;
            }
        };
        list.setAdapter(adapter);
    }

}

程序清單2

layout.XML

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <ListView
        android:id="@+id/list1"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >
    </ListView>

</LinearLayout>