下拉选择控件(PopupWindow)的使用

系统管理员 2022-08-01 00:16 199阅读 0赞

下拉选择控件的效果图如下：

![Image 1][]

要实现这样的效果可以使用PopupWindow来实现，代码如下：

1.MainActivity的代码：

public class MainActivity extends Activity implements OnClickListener{
    	private EditText editText;
    	private ImageView iv_select;
    	
    	private ArrayList<String> list = new ArrayList<String>();
    	private MyAdapter adapter;
    	private ListView listView;
    	
    	private int popupWindowHeight = 300;
    	private PopupWindow popupWindow;
    	@Override
    	protected void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		initView();
    		initListener();
    		initData();
    	}
    	
    	private void initListener() {
    		iv_select.setOnClickListener(this);
    	}
    	private void initView() {
    		setContentView(R.layout.activity_main);
    		editText = (EditText) findViewById(R.id.editText);
    		iv_select = (ImageView) findViewById(R.id.iv_select);
    	}
    	
    	private void initData() {
    		for (int i = 0; i < 15; i++) {
    			list.add(900000+i+"");
    		}
    		
    		initListView();
    	}
    	
    	private void initListView(){
    		listView = new ListView(this);
    		
    		listView.setBackgroundResource(R.drawable.listview_background);
    		listView.setVerticalScrollBarEnabled(false);//隐藏listview滚动条
    		
    		adapter = new MyAdapter();
    		listView.setAdapter(adapter);
    		
    		listView.setOnItemClickListener(new OnItemClickListener() {
    			@Override
    			public void onItemClick(AdapterView<?> parent, View view,
    					int position, long id) {
    				editText.setText(list.get(position));
    				popupWindow.dismiss();
    			}
    		});
    	}
    	
    	private void showNumberList(){
    		if(popupWindow==null){
    			popupWindow = new PopupWindow(listView, 
    					editText.getWidth(), popupWindowHeight);
    		}
    		//要让其中的view获取焦点，必须设置为true
    		popupWindow.setFocusable(true);
    		//还必须设置一个背景图片
    		popupWindow.setBackgroundDrawable(new BitmapDrawable());
    		//设置点击外部消失
    		popupWindow.setOutsideTouchable(true);
    		
    		popupWindow.showAsDropDown(editText, 0, 0);
    	}
    	
    	@Override
    	public void onClick(View v) {
    		switch (v.getId()) {
    		case R.id.iv_select:
    			showNumberList();
    			break;
    		}
    		
    	}
    
    	
    	class MyAdapter extends BaseAdapter{
    		@Override
    		public int getCount() {
    			return list.size();
    		}
    		@Override
    		public Object getItem(int position) {
    			return null;
    		}
    		@Override
    		public long getItemId(int position) {
    			return 0;
    		}
    		@Override
    		public View getView(final int position, View convertView, ViewGroup parent) {
    			final View view = View.inflate(MainActivity.this, R.layout.adapter_list, null);
    			TextView tv_number = (TextView) view.findViewById(R.id.tv_number);
    			ImageButton iv_delete = (ImageButton) view.findViewById(R.id.iv_delete);
    			
    			tv_number.setText(list.get(position));
    			iv_delete.setOnClickListener(new OnClickListener() {
    				@Override
    				public void onClick(View v) {
    					list.remove(position);
    					notifyDataSetChanged();
    					
    					int listviewHeight = view.getHeight()*list.size();
    					popupWindow.update(editText.getWidth(), listviewHeight>popupWindowHeight
    							?popupWindowHeight:listviewHeight);
    					
    					if(list.size()==0){
    						popupWindow.dismiss();
    						iv_select.setVisibility(View.GONE);
    					}
    				}
    			});
    			
    			return view;
    		}
    		
    	}
    
    }

2.布局文件activity\_main.xml和adapter\_list.xml代码如下：

activity\_main.xml：

adapter\_list.xm：

<?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="wrap_content"
        android:padding="5dp"
        android:gravity="center_vertical"
        android:descendantFocusability="blocksDescendants"
        android:orientation="horizontal" >
        
        <TextView android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:drawableLeft="@drawable/user"
            android:gravity="center_vertical"
            android:drawablePadding="3dp"
            android:id="@+id/tv_number"
            android:text="90000"/>
        
        <ImageButton android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/iv_delete"
            android:background="@drawable/delete"/>
    
    </LinearLayout>

注意点：假如listview的item中有Button，ImageButton,CheckBox等会强制获取焦点的view。 此时，listview的item无法获取焦点，从而无法被点击  
        解决方法：给item的根布局增加属性： android:descendantFocusability="blocksDescendants" 设置之后，Button获取焦点，item中其他控件也可以获取焦点

Demo地址：http://download.csdn.net/detail/qq\_26323183/8807173

[Image 1]: