Android中popupWindow的简单应用

学习Android也有两个多月了，之前一直没有写博客，所以接下来的博客也不会从最开始的那些很基本的控件写起，这次来介绍的是popupWindow。

popupWindow这个类用来实现一个弹出框，可以使用任意布局的View作为其内容，这个弹出框是悬浮在当前activity之上的。因为会弹出一个窗口，所以往往我们也会用到LayoutInflater，刚好可以复习一下上一篇博客的内容，话不多说，见代码。

MainActivity.java

package com.whisker.popupwindowtest;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.content.Context;import android.graphics.drawable.BitmapDrawable;import android.os.Bundle;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.View.OnClickListener;import android.view.WindowManager;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.ListView;import android.widget.PopupWindow;import android.widget.TextView;import android.widget.Toast;public class MainActivity extends Activity {private PopupWindow popupWindow;private View view;private View titleView;private TextView titleTextView;private ListView listView;private List<String> groups;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);                titleView = this.findViewById(R.id.top_title);        titleTextView = (TextView) titleView.findViewById(R.id.tvTitle);        titleTextView.setText("Text2");        titleTextView.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View view) {Log.i("123", "321");showWindow(view);}});    }private void showWindow(View parent) {if(popupWindow == null){LayoutInflater layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);view = layoutInflater.inflate(R.layout.group_list, null);listView = (ListView) view.findViewById(R.id.lvGroup);groups = new ArrayList<String>();groups.add("我的微博");groups.add("好友");groups.add("亲人");groups.add("陌生人");GroupAdapter groupAdapter = new GroupAdapter(this,groups);listView.setAdapter(groupAdapter);popupWindow = new PopupWindow(view,200,250);}popupWindow.setFocusable(true);popupWindow.setOutsideTouchable(true);popupWindow.setBackgroundDrawable(new BitmapDrawable());WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);int xPos = windowManager.getDefaultDisplay().getWidth()/2 - popupWindow.getWidth()/2;Log.i("whisker", "windowManager.getDefaultDisplay().getWidth()/2:" + windowManager.getDefaultDisplay().getWidth() / 2);Log.i("whisker", "popupWindow.getWidth()/2:" + popupWindow.getWidth() / 2);Log.i("whisker", "xPos:" + xPos);popupWindow.showAsDropDown(parent, xPos, 0);listView.setOnItemClickListener(new OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> arg0, View arg1, int position,long arg3) {Toast.makeText(MainActivity.this, "你点的是" + groups.get(position), Toast.LENGTH_LONG).show();if(popupWindow != null){popupWindow.dismiss();}}});}}

GroupAdapter是ListView中不可少的一个类，将ListView中的View和值进行一一对应，也就是我们说的键值对。

GroupAdapter.java

package com.whisker.popupwindowtest;import java.util.List;import android.content.Context;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.TextView;public class GroupAdapter extends BaseAdapter{private Context context;private List<String> list;public GroupAdapter(Context context,List<String> list){this.context = context;this.list = list;}@Overridepublic int getCount() {return list.size();}@Overridepublic Object getItem(int position) {return list.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup viewGroup) {ViewHolder holder;if (convertView == null) {convertView=LayoutInflater.from(context).inflate(R.layout.group_item_view, null);holder=new ViewHolder();convertView.setTag(holder);holder.groupItem=(TextView) convertView.findViewById(R.id.groupItem);}else{holder = (ViewHolder) convertView.getTag();}holder.groupItem.setText(list.get(position));return convertView;}static class ViewHolder{TextView groupItem; }}

activity_main.xml

<RelativeLayout 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"    tools:context="com.whisker.popupwindowtest.MainActivity" >    <include         android:id="@+id/top_title"        layout="@layout/title_two_button"/></RelativeLayout>

title_two_button

<?xml version="1.0" encoding="utf-8"?><FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="wrap_content" >        <TextView         android:id="@+id/tvTitle"        android:layout_width="match_parent"        android:layout_height="45dip"        android:background="@drawable/search_bg"        android:gravity="center"        android:text="Title"        android:textColor="@android:color/black"        android:textSize="25dip"/>        <Button         android:id="@+id/button_left"        android:layout_width="49dip"        android:layout_height="36dip"        android:layout_gravity="center_vertical"        android:background="@drawable/title_button"/>        <Button         android:id="@+id/button_right"        android:layout_width="49dip"        android:layout_height="36dip"        android:layout_gravity="right"        android:background="@drawable/title_button2"        android:layout_marginRight="2dip"        android:layout_marginTop="4dip"/>    </FrameLayout>

在这个xml文件中，我们看到两个Button空间中的background属性中指向了“button.xml”和“button2.xml”

这两个xml能够做到Button的动态变化，点击和非点击的不同效果

button.xml

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android" >    <item android:state_pressed="true" android:drawable="@drawable/title_new_selected"/>    <item android:drawable="@drawable/title_new_normal"/></selector>

button2.xml

<?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android" >    <item android:state_pressed="true" android:drawable="@drawable/title_reload_selected"/>    <item android:drawable="@drawable/title_reload_normal"/></selector>

我们看到了LayoutInflater指向了group_list这个xml，group_list.xml代码如下：

<?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="match_parent"    android:orientation="vertical"    android:background="@drawable/group_bg" >        <TextView         android:id="@+id/groupAll"        android:layout_width="match_parent"        android:layout_height="40dip"        android:gravity="center"        android:background="@drawable/grouplist_fixed_item_bg"        android:text="All"        style="@style/grouplist_item_textview" />        <ImageView         android:id="@+id/iv_group_list_bg_divider"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:background="@drawable/group_divider"        />        <ListView        android:id="@+id/lvGroup"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:listSelector="@drawable/grouplist_item_bg_sel"        android:drawSelectorOnTop="true"        android:divider="@drawable/group_divider"        android:cacheColorHint="#000000"        android:dividerHeight="2.0px"/>    </LinearLayout>

我们看到了，这里使用了一个style，是可以用在整个项目中的一个固定格式。

styles

<pre name="code" class="html"><resources xmlns:android="http://schemas.android.com/apk/res/android">    <!--        Base application theme, dependent on API level. This theme is replaced        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.    -->    <style name="AppBaseTheme" parent="android:Theme.Light">        <!--            Theme customizations available in newer API levels can go in            res/values-vXX/styles.xml, while customizations related to            backward-compatibility can go here.        -->    </style>    <!-- Application theme. -->    <style name="AppTheme" parent="AppBaseTheme">        <!-- All customizations that are NOT specific to a particular API-level can go here. -->    </style>        <style name="grouplist_item_textview">        <item name="android:textSize">18sp</item>        <item name="android:textColor">#ffffffff</item>    </style></resources>

group_item_view.xml

<pre name="code" class="html"><?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="40dip"    android:orientation="vertical" >        <TextView         android:id="@+id/groupItem"        android:gravity="center"        android:layout_width="match_parent"        android:layout_height="match_parent"        style="@style/grouplist_item_textview"/>    </LinearLayout>

</pre>groulist_fixed_bg.xml<pre>

<pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?><selector xmlns:android="http://schemas.android.com/apk/res/android" >    <item android:state_focused="true" android:state_pressed="true" android:drawable="@drawable/grouplist_item_bg_sel" />    <item android:state_focused="false" android:state_pressed="true" android:drawable="@drawable/grouplist_item_bg_sel" />    <item android:state_selected="true" android:drawable="@drawable/grouplist_item_bg_sel" />    <item android:state_focused="true" android:drawable="@drawable/grouplist_item_bg_sel" /></selector>

这就是整个程序的效果图