一:前言
本人参考博客:http://blog.csdn.net/jdsjlzx/article/details/41316417 最近在弄一个下拉框,发现Android自带的很难实现我的功能,于是去网上找到一份Demo,但是发现没有封装的好,并且还有很多重复的代码,于是我在这位前辈的基础上进行了修改.并且重新进行了封装,代码变得简单,并且具有可读性.
二:实现原理
1.就是一个TextView 弄一个弧形的背景图片,然后设置一个点击事件.
2.点击TextView之后显示一个PopupWindow,Popupwindow是自定义的,里面显示一个ListView.ListView也设置了左边.右边.底部的边框.
三:效果图如下
四:代码实现:
1).MainActivity.java 程序入口,初始化数据,初始化自定义PopupWIndow,TextView点击之后显示PopupWIndow,处理ListView的点击事件.
- /**
- * 主Activity 用来实现popupwindow
- * @author ansen
- */
- public class MainActivity extends Activity {
- private SpinerPopWindow<String> mSpinerPopWindow;
- private List<String> list;
- private TextView tvValue;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- initData();
- tvValue = (TextView) findViewById(R.id.tv_value);
- tvValue.setOnClickListener(clickListener);
- mSpinerPopWindow = new SpinerPopWindow<String>(this, list,itemClickListener);
- mSpinerPopWindow.setOnDismissListener(dismissListener);
- }
- /**
- * 监听popupwindow取消
- */
- private OnDismissListener dismissListener=new OnDismissListener() {
- @Override
- public void onDismiss() {
- setTextImage(R.drawable.icon_down);
- }
- };
- /**
- * popupwindow显示的ListView的item点击事件
- */
- private OnItemClickListener itemClickListener = new OnItemClickListener() {
- @Override
- public void onItemClick(AdapterView<?> parent, View view, int position,long id) {
- mSpinerPopWindow.dismiss();
- tvValue.setText(list.get(position));
- Toast.makeText(MainActivity.this, "点击了:" + list.get(position),Toast.LENGTH_LONG).show();
- }
- };
- /**
- * 显示PopupWindow
- */
- private OnClickListener clickListener = new OnClickListener() {
- @Override
- public void onClick(View v) {
- switch (v.getId()) {
- case R.id.tv_value:
- mSpinerPopWindow.setWidth(tvValue.getWidth());
- mSpinerPopWindow.showAsDropDown(tvValue);
- setTextImage(R.drawable.icon_up);
- break;
- }
- }
- };
- /**
- * 初始化数据
- */
- private void initData() {
- list = new ArrayList<String>();
- for (int i = 0; i < 5; i++) {
- list.add("test:" + i);
- }
- }
- /**
- * 给TextView右边设置图片
- * @param resId
- */
- private void setTextImage(int resId) {
- Drawable drawable = getResources().getDrawable(resId);
- drawable.setBounds(0, 0, drawable.getMinimumWidth(),drawable.getMinimumHeight());// 必须设置图片大小,否则不显示
- tvValue.setCompoundDrawables(null, null, drawable, null);
- }
- }
2).activity_main.xml 这个文件也没啥好说的 就是两个TextView。
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- xmlns:tools="http://schemas.android.com/tools"
- android:layout_width="match_parent"
- android:layout_height="match_parent"
- android:orientation="vertical" >
- <LinearLayout
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:layout_margin="5dp"
- android:orientation="horizontal">
- <TextView
- android:id="@+id/tv_value"
- android:layout_width="0dp"
- android:layout_height="wrap_content"
- android:layout_weight="1"
- android:background="@drawable/shape_help_category_tv_bg"
- android:drawableRight="@drawable/icon_down"
- android:padding="10dp"
- android:textColor="@color/content_color"
- android:text="请选择父类别"
- android:textSize="20sp"/>
- <TextView
- android:layout_marginLeft="5dp"
- android:layout_width="0dp"
- android:layout_height="wrap_content"
- android:layout_weight="1"
- android:background="@drawable/shape_help_category_tv_bg"
- android:drawableRight="@drawable/icon_down"
- android:textColor="@color/content_color"
- android:padding="10dp"
- android:text="请选择子类别"
- android:textSize="20sp" />
- </LinearLayout>
- </LinearLayout>
3).SpinerPopWindow.java 自定义Popupwindow类 初始化PopupWindow显示的布局,以及一些参数,并且给listView设置适配器
- * 自定义PopupWindow 主要用来显示ListView
- * @author Ansen
- * @param <T>
- * @param <T>
- * @create time 2015-11-3
- */
- public class SpinerPopWindow<T> extends PopupWindow {
- private LayoutInflater inflater;
- private ListView mListView;
- private List<T> list;
- private MyAdapter mAdapter;
- public SpinerPopWindow(Context context,List<T> list,OnItemClickListener clickListener) {
- super(context);
- inflater=LayoutInflater.from(context);
- this.list=list;
- init(clickListener);
- }
- private void init(OnItemClickListener clickListener){
- View view = inflater.inflate(R.layout.spiner_window_layout, null);
- setContentView(view);
- setWidth(LayoutParams.WRAP_CONTENT);
- setHeight(LayoutParams.WRAP_CONTENT);
- setFocusable(true);
- ColorDrawable dw = new ColorDrawable(0x00);
- setBackgroundDrawable(dw);
- mListView = (ListView) view.findViewById(R.id.listview);
- mListView.setAdapter(mAdapter=new MyAdapter());
- mListView.setOnItemClickListener(clickListener);
- }
- private class MyAdapter extends BaseAdapter{
- @Override
- public int getCount() {
- return list.size();
- }
- @Override
- public Object getItem(int position) {
- return list.get(position);
- }
- @Override
- public long getItemId(int position) {
- return position;
- }
- @Override
- public View getView(int position, View convertView, ViewGroup parent) {
- ViewHolder holder=null;
- if(convertView==null){
- holder=new ViewHolder();
- convertView=inflater.inflate(R.layout.spiner_item_layout, null);
- holder.tvName=(TextView) convertView.findViewById(R.id.tv_name);
- convertView.setTag(holder);
- }else{
- holder=(ViewHolder) convertView.getTag();
- }
- holder.tvName.setText(getItem(position).toString());
- return convertView;
- }
- }
- private class ViewHolder{
- private TextView tvName;
- }
- }
4).spiner_window_layout.xml PopupWindow显示的布局文件 里面就一个ListView控件
- <?xml version="1.0" encoding="utf-8"?>
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:layout_alignParentRight="true"
- android:orientation="vertical">
- <ListView
- android:id="@+id/listview"
- android:layout_width="fill_parent"
- android:layout_height="wrap_content"
- android:cacheColorHint="#00000000"
- android:background="@drawable/shape_popupwindow_list_bg"
- android:scrollbars="none" >
- </ListView>
- </LinearLayout>
还有一些其他布局,我就不一一贴出来了,有兴趣的可以去看看源码.这个Demo还是比较简单的,相信大家都能看懂.
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