android彈出窗口的實現（PopupWindow）

           最近看到新浪微博頂部欄的微博分組效果很炫，從網上查了一些資料明白原來是用PopupWindow實現的，今天自己也寫了一個例子實現了這種效果，希望對大家有幫助。

         PopupWindow就是彈出窗口的意思，類似windows下面的開始按鈕。PopupWindow可以實現浮層效果，而且可以自定義顯示位置，出現和退出時的動畫.

            首先定義新浪微博的頂部欄,title_two_button.xml和main.xml

<?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="天堂沒有路"
        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>

<?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>

接下來定義彈出對話框的布局文件group_list.xml和group_item_view.xml

<?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>

<?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>

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;
    }

}

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("天堂沒有路");

        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);
            // 加載數據
            groups = new ArrayList<String>();
            groups.add("全部");
            groups.add("我的微博");
            groups.add("好友");
            groups.add("親人");
            groups.add("同學");
            groups.add("朋友");
            groups.add("陌生人");

            GroupAdapter groupAdapter = new GroupAdapter(this, groups);
            lv_group.setAdapter(groupAdapter);
            // 創建一個PopuWidow對象
            popupWindow = new PopupWindow(view, 300, 350);
        }

        // 使其聚集
        popupWindow.setFocusable(true);
        // 設置允許在外點擊消失
        popupWindow.setOutsideTouchable(true);

        // 這個是為了點擊“返回Back”也能使其消失，并且并不會影響你的背景
        popupWindow.setBackgroundDrawable(new BitmapDrawable());
        WindowManager windowManager = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
        // 顯示的位置為:屏幕的寬度的一半-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();
                }
            }
        });
    }
}

再看一張新浪微博的彈出對話框效果：

轉自：http://blog.csdn.net/wangkuifeng0118/article/details/7368157