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() {

@Override
public 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() {

@Override
public 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;
}

@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 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