WindowManager
在前面《Android开发笔记(六十六)自定义对话框》中,我们提到每个页面都是一个Window窗口,许多的Window对象需要一个管家来打理,这个管家我们称之为WindowManager窗口管理。在手机屏幕上新增或删除页面窗口,都可以归结为WindowManager的操作,下面是该管理类的常用方法说明:
getDefaultDisplay : 获取默认的显示屏信息。通常用该方法获取屏幕分辨率,详情参见《Android开发笔记(三)屏幕分辨率》。
addView : 往窗口添加视图。第二个参数为WindowManager.LayoutParams对象。
updateViewLayout : 更新指定视图的布局参数。第二个参数为WindowManager.LayoutParams对象。
removeView : 往窗口移除指定视图。
下面是窗口布局参数WindowManager.LayoutParams的常用属性说明:
format : 窗口的像素点格式。取值见PixelFormat类中的常量定义,一般取值PixelFormat.RGBA_8888。
type : 窗口的显示类型,常用的类型说明如下:
--TYPE_SYSTEM_ALERT : 系统警告提示。
--TYPE_SYSTEM_ERROR : 系统错误提示。
--TYPE_SYSTEM_OVERLAY : 页面顶层提示。
--TYPE_SYSTEM_DIALOG : 系统对话框。
--TYPE_STATUS_BAR : 状态栏
--TYPE_TOAST : 短暂通知Toast
flags : 窗口的行为准则,常用的标志位如下说明(对于悬浮窗来说,一般只需设置FLAG_NOT_FOCUSABLE):
--FLAG_NOT_FOCUSABLE : 不能抢占焦点,即不接受任何按键或按钮事件。
--FLAG_NOT_TOUCHABLE : 不接受触摸屏事件。悬浮窗一般不设置该标志,因为一旦设置该标志,将无法拖动悬浮窗。
--FLAG_NOT_TOUCH_MODAL : 当窗口允许获得焦点时(即没有设置FLAG_NOT_FOCUSALBE标志),仍然将窗口之外的按键事件发送给后面的窗口处理。否则它将独占所有的按键事件,而不管它们是不是发生在窗口范围之内。
-- :
--FLAG_LAYOUT_IN_SCREEN : 允许窗口占满整个屏幕。
--FLAG_LAYOUT_NO_LIMITS : 允许窗口扩展到屏幕之外。
--FLAG_WATCH_OUTSIDE_TOUCH : 如果设置了FLAG_NOT_TOUCH_MODAL标志,则当按键动作发生在窗口之外时,将接收到一个MotionEvent.ACTION_OUTSIDE事件。
alpha : 窗口的透明度,取值为0-1。
gravity : 取值同View的setGravity方法。
x : 窗口左上角的X坐标。
y : 窗口左上角的Y坐标。
width : 窗口的宽度。
height : 窗口的高度。
静态悬浮窗
悬浮窗有点类似对话框,它们都是独立于Activity页面的窗口,但是悬浮窗又有一些与众不同的特性,例如:
1、悬浮窗是可以拖动的,对话框则不能;
2、悬浮窗不妨碍用户触摸窗外的区域,对话框则不让用户框外的控件;
3、悬浮窗独立于Activity页面,即当页面退出后,悬浮窗仍停留在屏幕上;而对话框与Activity页面是共存关系,一旦页面退出则对话框也消失了;
基于悬浮窗的以上特性,我们要实现窗口的悬浮效果,就不仅仅是调用WindowManager的addView方法那么简单了,而是需要做一系列的自定义处理,具体步骤如下:
1、在AndroidManifest.xml中声明系统窗口权限,即增加下面这句:
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
2、在自定义的悬浮窗控件中,要设置触摸监听器,并根据用户的手势滑动来相应调整窗口位置,以实现悬浮窗的拖动功能;
3、合理设置悬浮窗的窗口参数,主要是把窗口参数的显示类型设置为TYPE_SYSTEM_ALERT或者TYPE_SYSTEM_ERROR,另外要设置标志位FLAG_NOT_FOCUSABLE;
4、在构造悬浮窗实例时,要传入Application的上下文Context,这是为了保证即使退出Activity,也不会关闭悬浮窗。因为Application对象在app运行过程中是始终存在着的,而Activity对象只在打开页面时有效,一旦退出页面则Activity的上下文就立刻回收(这会导致依赖于该上下文的悬浮窗也一块被回收了)。
下面是一个静态悬浮窗的效果截图:
下面是自定义悬浮窗的示例代码:
import android.content.Context; import android.graphics.PixelFormat; import android.view.Gravity; import android.view.LayoutInflater; import android.view.MotionEvent; import android.view.View; import android.view.WindowManager; public class FloatView extends View { private final static String TAG = "FloatView"; private Context mContext; private WindowManager wm; private static WindowManager.LayoutParams wmParams; public View mContentView; private float mRelativeX; private float mRelativeY; private float mScreenX; private float mScreenY; private boolean bShow = false; public FloatView(Context context) { super(context); wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); if (wmParams == null) { wmParams = new WindowManager.LayoutParams(); } mContext = context; } public void setLayout(int layout_id) { mContentView = LayoutInflater.from(mContext).inflate(layout_id, null); mContentView.setOnTouchListener(new OnTouchListener() { public boolean onTouch(View v, MotionEvent event) { mScreenX = event.getRawX(); mScreenY = event.getRawY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: mRelativeX = event.getX(); mRelativeY = event.getY(); break; case MotionEvent.ACTION_MOVE: updateViewPosition(); break; case MotionEvent.ACTION_UP: updateViewPosition(); mRelativeX = mRelativeY = 0; break; } return true; } }); } private void updateViewPosition() { wmParams.x = (int) (mScreenX - mRelativeX); wmParams.y = (int) (mScreenY - mRelativeY); wm.updateViewLayout(mContentView, wmParams); } public void show() { if (mContentView != null) { wmParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT; wmParams.format = PixelFormat.RGBA_8888; wmParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE; wmParams.alpha = 1.0f; wmParams.gravity = Gravity.LEFT | Gravity.TOP; wmParams.x = 0; wmParams.y = 0; wmParams.width = WindowManager.LayoutParams.WRAP_CONTENT; wmParams.height = WindowManager.LayoutParams.WRAP_CONTENT; // 显示自定义悬浮窗口 wm.addView(mContentView, wmParams); bShow = true; } } public void close() { if (mContentView != null) { wm.removeView(mContentView); bShow = false; } } public boolean isShow() { return bShow; } }
下面是打开/关闭悬浮窗的页面代码:
import com.example.exmfloat.widget.FloatView; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class StaticActivity extends Activity implements OnClickListener { private FloatView mFloatView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_static); Button btn_static_open = (Button) findViewById(R.id.btn_static_open); Button btn_static_close = (Button) findViewById(R.id.btn_static_close); btn_static_open.setOnClickListener(this); btn_static_close.setOnClickListener(this); mFloatView = new FloatView(MainApplication.getInstance()); mFloatView.setLayout(R.layout.float_static); } @Override public void onClick(View v) { if (v.getId() == R.id.btn_static_open) { if (mFloatView!=null && mFloatView.isShow()==false) { mFloatView.show(); } } else if (v.getId() == R.id.btn_static_close) { if (mFloatView!=null && mFloatView.isShow()==true) { mFloatView.close(); } } } }
下面是自定义Application的代码例子:
import android.app.Application; public class MainApplication extends Application { private static MainApplication mApp; public static MainApplication getInstance() { return mApp; } @Override public void onCreate() { super.onCreate(); mApp = this; } }
动态悬浮窗
在实际开发中,悬浮窗的展示内容是变化的,毕竟一个内容不变的悬浮窗对用户来说没什么用处。具体的应用例子有很多,比如说时钟、天气、实时流量、股市指数等等,下面就以实时流量与股市指数两个例子,来详细说明动态悬浮窗的实际应用。
要想实时刷新悬浮窗,这得通过服务Service来实现,所以动态悬浮窗要在Service服务中创建和更新,页面只负责启动/停止服务。对于手机的实时流量,可以通过TrafficStats类的相关方法计算得到,该类的详细说明参见《Android开发笔记(七十九)资源与权限校验》。
下面是实时流量悬浮窗的效果截图:
下面是实时流量悬浮窗的页面代码:
import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import com.example.exmfloat.service.TrafficService; public class TrafficActivity extends Activity implements OnClickListener { private final static String TAG = "TrafficActivity"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_traffic); Button btn_traffic_open = (Button) findViewById(R.id.btn_traffic_open); Button btn_traffic_close = (Button) findViewById(R.id.btn_traffic_close); btn_traffic_open.setOnClickListener(this); btn_traffic_close.setOnClickListener(this); } @Override public void onClick(View v) { if (v.getId() == R.id.btn_traffic_open) { Intent intent = new Intent(this, TrafficService.class); intent.putExtra("type", TrafficService.OPEN); startService(intent); } else if (v.getId() == R.id.btn_traffic_close) { Intent intent = new Intent(this, TrafficService.class); intent.putExtra("type", TrafficService.CLOSE); startService(intent); } } }
下面是实时流量悬浮窗的服务代码:
import com.example.exmfloat.MainApplication; import com.example.exmfloat.R; import com.example.exmfloat.util.FlowUtil; import com.example.exmfloat.widget.FloatView; import android.app.Service; import android.content.Intent; import android.net.TrafficStats; import android.os.Handler; import android.os.IBinder; import android.util.Log; import android.widget.TextView; public class TrafficService extends Service { private final static String TAG = "TrafficService"; public static int OPEN = 0; public static int CLOSE = 1; private long curRx; private long curTx; private FloatView mFloatView; private TextView tv_traffic; private final int delayTime = 2000; private Handler mHandler = new Handler(); private Runnable mRefresh = new Runnable() { public void run() { if (mFloatView != null && mFloatView.isShow() == true && (TrafficStats.getTotalRxBytes()>curRx || TrafficStats.getTotalTxBytes()>curTx)) { long a = ((TrafficStats.getTotalRxBytes() - curRx) + (TrafficStats .getTotalTxBytes() - curTx)) / 2; String desc = String.format("当前流量: %s/S", FlowUtil.BToShowStringNoDecimals(a)); tv_traffic.setText(desc); curRx = TrafficStats.getTotalRxBytes(); curTx = TrafficStats.getTotalTxBytes(); } mHandler.postDelayed(this, delayTime); } }; @Override public IBinder onBind(Intent intent) { return null; } @Override public void onCreate() { super.onCreate(); if (mFloatView == null) { mFloatView = new FloatView(MainApplication.getInstance()); mFloatView.setLayout(R.layout.float_traffic); tv_traffic = (TextView) mFloatView.mContentView.findViewById(R.id.tv_traffic); } curRx = TrafficStats.getTotalRxBytes(); curTx = TrafficStats.getTotalTxBytes(); mHandler.postDelayed(mRefresh, 0); } @Override public int onStartCommand(Intent intent, int flags, int startId) { if (intent != null) { int type = intent.getIntExtra("type", OPEN); if (type == OPEN) { if (mFloatView != null && mFloatView.isShow() == false) { mFloatView.show(); } } else if (type == CLOSE) { if (mFloatView != null && mFloatView.isShow() == true) { mFloatView.close(); } stopSelf(); } } return super.onStartCommand(intent, flags, startId); } @Override public void onDestroy() { super.onDestroy(); mHandler.removeCallbacks(mRefresh); } }
对于股市指数的展示,可以通过调用财经网站的实时指数查询接口得到,比如新浪财经与腾讯财经均提供了上证指数与深圳成指的查询接口。
下面是实时股指悬浮窗的效果截图:
下面是实时股指悬浮窗的页面代码:
import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import com.example.exmfloat.service.StockService; public class StockActivity extends Activity implements OnClickListener { private final static String TAG = "StockActivity"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_stock); Button btn_stock_open = (Button) findViewById(R.id.btn_stock_open); Button btn_stock_close = (Button) findViewById(R.id.btn_stock_close); btn_stock_open.setOnClickListener(this); btn_stock_close.setOnClickListener(this); } @Override public void onClick(View v) { if (v.getId() == R.id.btn_stock_open) { Intent intent = new Intent(this, StockService.class); intent.putExtra("type", StockService.OPEN); startService(intent); } else if (v.getId() == R.id.btn_stock_close) { Intent intent = new Intent(this, StockService.class); intent.putExtra("type", StockService.CLOSE); startService(intent); } } }
下面是实时股指悬浮窗的服务代码:
import com.example.exmfloat.MainApplication; import com.example.exmfloat.R; import com.example.exmfloat.http.HttpReqData; import com.example.exmfloat.http.HttpRespData; import com.example.exmfloat.http.HttpUrlUtil; import com.example.exmfloat.widget.FloatView; import android.app.Service; import android.content.Intent; import android.graphics.Color; import android.os.Handler; import android.os.IBinder; import android.os.Message; import android.widget.TextView; public class StockService extends Service { private final static String TAG = "StockService"; public static int OPEN = 0; public static int CLOSE = 1; private FloatView mFloatView; private TextView tv_sh_stock, tv_sz_stock; private final int delayTime = 5000; private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { //上证指数,3019.9873,-5.6932,-0.19,1348069,14969598 String desc = (String) msg.obj; String[] array = desc.split(","); String stock = array[1]; float distance = Float.parseFloat(array[2]); String range = array[3]; String text = String.format("%s %s%%", stock, range); int type = msg.what; if (type == SHANGHAI) { tv_sh_stock.setText(text); if (distance > 0) { tv_sh_stock.setTextColor(Color.RED); } else { tv_sh_stock.setTextColor(Color.GREEN); } } else if (type == SHENZHEN) { tv_sz_stock.setText(text); if (distance > 0) { tv_sz_stock.setTextColor(Color.RED); } else { tv_sz_stock.setTextColor(Color.GREEN); } } } }; private Runnable mRefresh = new Runnable() { @Override public void run() { if (mFloatView != null && mFloatView.isShow() == true ) { new StockThread(SHANGHAI).start(); new StockThread(SHENZHEN).start(); } mHandler.postDelayed(this, delayTime); } }; private static int SHANGHAI = 0; private static int SHENZHEN = 1; private class StockThread extends Thread { private int mType; public StockThread(int type) { mType = type; } @Override public void run() { HttpReqData req_data = new HttpReqData(); if (mType == SHANGHAI) { req_data.url = "http://hq.sinajs.cn/list=s_sh000001"; } else if (mType == SHENZHEN) { req_data.url = "http://hq.sinajs.cn/list=s_sz399001"; } HttpRespData resp_data = HttpUrlUtil.getData(req_data); //var hq_str_s_sh000001="上证指数,3019.9873,-5.6932,-0.19,1348069,14969598"; String desc = resp_data.content; Message msg = Message.obtain(); msg.what = mType; msg.obj = desc.substring(desc.indexOf("\"")+1, desc.lastIndexOf("\"")); mHandler.sendMessage(msg); } } @Override public IBinder onBind(Intent intent) { return null; } @Override public void onCreate() { super.onCreate(); if (mFloatView == null) { mFloatView = new FloatView(MainApplication.getInstance()); mFloatView.setLayout(R.layout.float_stock); tv_sh_stock = (TextView) mFloatView.mContentView.findViewById(R.id.tv_sh_stock); tv_sz_stock = (TextView) mFloatView.mContentView.findViewById(R.id.tv_sz_stock); } mHandler.postDelayed(mRefresh, 0); } @Override public int onStartCommand(Intent intent, int flags, int startId) { if (intent != null) { int type = intent.getIntExtra("type", OPEN); if (type == OPEN) { if (mFloatView != null && mFloatView.isShow() == false) { mFloatView.show(); } } else if (type == CLOSE) { if (mFloatView != null && mFloatView.isShow() == true) { mFloatView.close(); } stopSelf(); } } return super.onStartCommand(intent, flags, startId); } @Override public void onDestroy() { super.onDestroy(); mHandler.removeCallbacks(mRefresh); } }