android弹出窗口的实现（PopupWindow）

最近看到新浪微博顶部栏的微博分组效果很炫，从网上查了一些资料明白原来是用PopupWindow实现的，今天自己也写了一个例子实现了这种效果，希望对大家有帮助。
PopupWindow就是弹出窗口的意思，类似windows下面的开始按钮。PopupWindow可以实现浮层效果，而且可以自定义显示位置，出现和退出时的动画.

首先定义新浪微博的顶部栏,title_two_button.xml和main.xml

[html]
view plaincopy

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >

<TextView
android:id="@+id/tvtitle"
android:layout_width="fill_parent"
android:layout_height="45dip"
android:background="@drawable/search_bg"
android:gravity="center"
android:text="天堂没有路"
android:textColor="@color/black"
android:textSize="25dip" />

<Button
android:id="@+id/btn_title_left"
android:layout_width="50dip"
android:layout_height="35dip"
android:layout_gravity="center_vertical"
android:background="@drawable/title_button"
android:textColor="@color/white" />

<Button
android:id="@+id/btn_title_right"
android:layout_width="50dip"
android:layout_height="35dip"
android:layout_gravity="right"
android:layout_marginRight="2dip"
android:layout_marginTop="4dip"
android:background="@drawable/title_button2"
android:textColor="@color/white" />

</FrameLayout>

[html]
view plaincopy

<?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="fill_parent"
android:background="@android:color/white"
android:orientation="vertical" >

<include
android:id="@+id/top_title"
layout="@layout/title_two_button" />

</LinearLayout>

主要是为了实现一个这样的界面：



接下来定义弹出对话框的布局文件group_list.xml和group_item_view.xml

[html]
view plaincopy

<?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="fill_parent"
android:background="@drawable/group_bg"
android:orientation="vertical"
>

<ImageView
android:id="@+id/iv_group_list_bg_divider"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/group_divider"
/>

<ListView
android:id="@+id/lvGroup"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:divider="@drawable/group_divider"
/>

</LinearLayout>

[html]
view plaincopy

<?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="@dimen/group_item_height"
android:orientation="vertical" >

<TextView
android:id="@+id/groupItem"
android:textColor="#ffffff"
android:textSize="18dp"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center" />

</LinearLayout>

自定义一个适配器：GroupAdapter

[html]
view plaincopy

import java.util.List;

import cn.com.karl.popwindow.R;

import android.content.Context;
import android.graphics.Color;
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.setTextColor(Color.BLACK);
holder.groupItem.setText(list.get(position));

return convertView;
}

static class ViewHolder {
TextView groupItem;
}

}

最后是我要实现弹出对话框的核心类PoupWindowDemoActivity

[html]
view plaincopy

import java.util.ArrayList;
import java.util.List;

import cn.com.karl.adapter.GroupAdapter;

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.Window;
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 PoupWindowDemoActivity extends Activity {

private PopupWindow popupWindow;

private ListView lv_group;

private View view;

private View top_title;

private TextView tvtitle;

private List<String> groups;

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);

top_title = this.findViewById(R.id.top_title);

tvtitle = (TextView) top_title.findViewById(R.id.tvtitle);

tvtitle.setText("天堂没有路");

tvtitle.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
showWindow(v);
}
});

}

private void showWindow(View parent) {

if (popupWindow == null) {
LayoutInflater layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

view = layoutInflater.inflate(R.layout.group_list, null);

lv_group = (ListView) view.findViewById(R.id.lvGroup);
// 加载数据
groups = new ArrayList<String>();
groups.add("全部");
groups.add("我的微博");
groups.add("好友");
groups.add("亲人");
groups.add("同学");
groups.add("朋友");
groups.add("陌生人");

GroupAdapter groupAdapter = new GroupAdapter(this, groups);
lv_group.setAdapter(groupAdapter);
// 创建一个PopuWidow对象
popupWindow = new PopupWindow(view, 300, 350);
}

// 使其聚集
popupWindow.setFocusable(true);
// 设置允许在外点击消失
popupWindow.setOutsideTouchable(true);

// 这个是为了点击“返回Back”也能使其消失，并且并不会影响你的背景
popupWindow.setBackgroundDrawable(new BitmapDrawable());
WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
// 显示的位置为:屏幕的宽度的一半-PopupWindow的高度的一半
int xPos = windowManager.getDefaultDisplay().getWidth() / 2
- popupWindow.getWidth() / 2;
Log.i("coder", "xPos:" + xPos);

popupWindow.showAsDropDown(parent, xPos, 0);

lv_group.setOnItemClickListener(new OnItemClickListener() {

@Override
public void onItemClick(AdapterView<?> adapterView, View view,
int position, long id) {

Toast.makeText(PoupWindowDemoActivity.this,
groups.get(position), 1000)
.show();

if (popupWindow != null) {
popupWindow.dismiss();
}
}
});
}
}

这样就完成了一个弹出对话框的效果，下面来看一下吧！



再看一张新浪微博的弹出对话框效果：



已经完成，我们可以把这项功能加入自己的做的新浪微博里，为自己的应用增添点特色色彩吧！

转自：http://blog.csdn.net/wangjia55/article/details/7495136