高级控件【安卓5】——ListActivity

ListActivity的使用

ListActivity类中集成了一个ListView控件。

通过继承ListActivity类可方便地使用ListView控件

 1 public class 类名extends ListActivity {
 2     protected void onCreate(Bundle savedInstanceState) {
 3         super.onCreate (savedInstanceState);
 4         //获取资源文件中的数组
 5         String [] data=getResources().getStringArray(R.array.city);
 6         ArrayAdapter<String> adapter=new ArrayAdapter<String> (this,
 7                 android.R.layout.simple_list_item_multiple_choice,data); //样式为复选框
 8         setListAdapter (adapter);
 9         ListView listView=getListView ();        //获取ListActivity自带的ListView对象
10         //设置ListView的选择行为：复选
11         listView.setChoiceMode (ListView.CHOICE_MODE_MULTIPLE);
12     }
13 }

应用ListActivity的部分代码

网格列表GridView（按多行多列显示信息）

<LinearLayout
  android: layout_width="fill_parent"
  android: layout_height="fill_parent">
<ImageView
    android:id="@+id/Img"
    android: layout_width="90dp"
    android: layout_height="100dp"
    android:scaleType="fitXY"    //设置所有图片大小一致
    android:padding="1px"/>    //设置四周边距为1像素
</LinearLayout>

ImageView

<LinearLayout
  android: layout_width="fill_parent"
  android: layout_height="fill_parent">
  <GridView
      android:id="@+id/gv"
      android: layout_width="fill_parent"
      android: layout_height="fill_parent"
      android:numColumns="3"                 //设置所有图片大小一致
      android:stretchMode="columnWidth"/>     //设置所有图片大小一致
</LinearLayout>

GridView

 1 GridView gv = (GridView) findViewById(R.id.gv);        //找到控件
 2     Field[] fields = R.drawable.class.getDeclaredFields();    //读到png结尾的图片
 3     List<Map<String, Integer>> data = new ArrayList<Map<String, Integer>>();
 4     for (Field field : fields) {
 5         Map<String, Integer> map = new HashMap<String, Integer>();
 6             try {
 7                 map.put("img", field.getInt(R.drawable.class));
 8                 data.add(map);
 9             } catch (IllegalArgumentException e) {
10                  e.printStackTrace();
11             } catch (IllegalAccessException e) {
12                  e.printStackTrace();
13             }
14     }
15     SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.gridview0,
16             new String[] { "img" },new int[] { R.id.GImg });            //创建适配器
17     gv.setAdapter(adapter);            //添加GridView对象
18
19     gv.setOnItemClickListener(new OnItemClickListener() {
20         public void onItemClick(AdapterView<?> adp, View view, int position, long arg) {
21             Map<String, Integer> map= (Map<String, Integer>)adp.getItemAtPosition(position);
22             int imgId=map.get("img");
23             ImageView iv=new ImageView(GridView0.this);
24             iv.setScaleType(ImageView.ScaleType.CENTER);
25             iv.setImageResource(imgId);
26             final Dialog da=new AlertDialog.Builder(GridView0.this).setTitle("展示图片").setView(iv).create();
27                 new Thread(){        //设置线程，让对话框在5秒后关闭
28                     public void run(){
29                         try {
30                             Thread.sleep(5000);
31                         } catch (InterruptedException e) {
32                              e.printStackTrace();
33                         }finally{
34                             da.dismiss();
35                         }
36                     }
37                 }.start();
38             da.show();
39     }
40 });

GridView部分java代码