【安卓5】高级控件——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

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

网格列表GridView（按多行多列显示信息）

方法	属性	描述
public GridView(Context context)		创建GridView对象
public void setStretchMode(int stretchMode)	android:stretchMode	缩放模式
public void setVerticalSpacing(int verticalSpacing)	android: verticalSpacing	设置垂直间距
public void setHorizontalSpacing(int horizontalSpacing)	android: horizontalSpacing	设置水平间距
public void setNumColumns(int numColumns)	android: numColumns	设置每列显示的数据量，若设置为auto——fit则表示自动设置
public void setSelection(int position)		设置默认选中项
public void setGravity(int gravity)	android: gravity	设置对齐模式，由Grivity类指定
public void setAdapter(ListAdapter adapter)		设置图片集

<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>

<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 gv = (GridView) findViewById(R.id.gv);        //找到控件
    Field[] fields = R.drawable.class.getDeclaredFields();    //读到png结尾的图片
    List<Map<String, Integer>> data = new ArrayList<Map<String, Integer>>();
    for (Field field : fields) {
        Map<String, Integer> map = new HashMap<String, Integer>();
            try {         
                map.put("img", field.getInt(R.drawable.class));
                data.add(map);
            } catch (IllegalArgumentException e) {        
                 e.printStackTrace();
            } catch (IllegalAccessException e) {        
                 e.printStackTrace();        
            }
    }
    SimpleAdapter adapter = new SimpleAdapter(this, data, R.layout.gridview0, 
            new String[] { "img" },new int[] { R.id.GImg });            //创建适配器
    gv.setAdapter(adapter);            //添加GridView对象

    gv.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> adp, View view, int position, long arg) {
            Map<String, Integer> map= (Map<String, Integer>)adp.getItemAtPosition(position);
            int imgId=map.get("img");
            ImageView iv=new ImageView(GridView0.this);
            iv.setScaleType(ImageView.ScaleType.CENTER);
            iv.setImageResource(imgId);
            final Dialog da=new AlertDialog.Builder(GridView0.this).setTitle("展示图片").setView(iv).create();
                new Thread(){        //设置线程，让对话框在5秒后关闭
                    public void run(){
                        try {         
                            Thread.sleep(5000);
                        } catch (InterruptedException e) {            
                             e.printStackTrace();    
                        }finally{             
                            da.dismiss();    
                        }
                    }
                }.start();
            da.show();
    }
});