举例说明ListView的用法

       通过在Layout中添加ListView Widget可以达到在页面布局具有列表效果的交互页面。在这里通过举例来说明怎样在Layout中添加ListView以及怎样应用。

       配合设计了两个事件Listener:  OnItemSelectedListener事件为鼠标的滚轮转动时所选择的值；OnItemClickListener事件则为当鼠标单击时，所触发的事件。由此可以区别出list中的“选择”与“单击”差异。

       使用ArrayAdapter(Context  context, int  textViewResourceId , T[] objects)这个构造器，其中textViewResourceId是定义在“res/layout/my_simple_list_item.xml”里的资源ResourceID(R.layout.my_simple_list_item),里面使用CheckedTextView来取得ListView中选择的项目。

       程序中使用了LinearLayout对象，动态地将TextView与ListView附加进原有的Layout布局当中。用LinearLayout.LayoutParams来创建对象param1,再调用LinearLayout的addView方法将TextView和ListView以及params对象传入。

   

程序如下所示：

public class A07Activity extends Activity {
 private static final String[]week="sunday","monday","tuesday","wednesday","thursday","friday","saturday"};
 private TextView tv;
 private ListView lv;
 private ArrayAdapter<String> aa;
 private LinearLayout ll;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
       
        tv=new TextView(this);
        tv.setText(R.string.title);
        tv.setTextColor(Color.RED);
        lv=new ListView(this);
        lv.setBackgroundColor(Color.GREEN);
        ll=new LinearLayout(this);
        ll.setOrientation(LinearLayout.VERTICAL);
        ll.setBackgroundColor(android.graphics.Color.YELLOW);
        aa=new ArrayAdapter<String>(A07Activity.this,R.layout.my_simple_list,week);
        lv.setAdapter(aa);
        LinearLayout.LayoutParams params01=new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        ll.addView(lv, params01);
        LinearLayout.LayoutParams params02=new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        ll.addView(tv, params02);
        setContentView(ll);
       
        lv.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

   @Override
   public void onItemSelected(AdapterView<?> arg0, View arg1,
     int arg2, long arg3) {
    // TODO Auto-generated method stub
    tv.setText("你选择的是："+arg0.getSelectedItem().toString());
   }

   @Override
   public void onNothingSelected(AdapterView<?> arg0) {
    // TODO Auto-generated method stub
    
   }
  });
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {

   @Override
   public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
     long arg3) {
    // TODO Auto-generated method stub
    tv.setText("你选择的是："+week[arg2]);
   }
  });
    }
}

 

res/layout/my_simple_list.xml如下:

<?xml version="1.0" encoding="utf-8"?>
<CheckedTextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/myCheckedTextView1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
   
/>