android悬浮窗--获取内存

迷途d书童 发布于 2012/03/30 14:07
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          首先,得先说明,这个例子并不是我写的,是从eoeAndroid的一个帖子上面看到的,下载了他的源代码,然后分析一下,供学习共享。(另外,对于其代码有所修改,以便于更好的说明问题,另:同时把源代码上传,下载地址:http://download.csdn.net/detail/aomandeshangxiao/3880055

         一开始,我们先看一下运行效果:

其中,

这一块就是悬浮窗,可以随意拖动,动态显示当前内存使用量。

         下面看一下代码是如何实现的:

悬浮窗的实现是用了一个service,为什么要用service呢?了解service特点的大体就会明白。下面看一下:

public class FloatService extends Service {

	WindowManager wm = null;
	WindowManager.LayoutParams wmParams = null;
	View view;
	private float mTouchStartX;
	private float mTouchStartY;
	private float x;
	private float y;
	int state;
	TextView tx1;
	TextView tx;
	ImageView iv;
	private float StartX;
	private float StartY;
	int delaytime=1000;
	@Override
	public void onCreate() {
		Log.d("FloatService", "onCreate");
		super.onCreate();
		view = LayoutInflater.from(this).inflate(R.layout.floating, null);
		tx = (TextView) view.findViewById(R.id.memunused);
		tx1 = (TextView) view.findViewById(R.id.memtotal);
		tx.setText("" + memInfo.getmem_UNUSED(this) + "KB");
		tx1.setText("" + memInfo.getmem_TOLAL() + "KB");
		iv = (ImageView) view.findViewById(R.id.img2);
		iv.setVisibility(View.GONE);
		createView();
		handler.postDelayed(task, delaytime);
	}

	private void createView() {
		// 获取WindowManager
		wm = (WindowManager) getApplicationContext().getSystemService("window");
		// 设置LayoutParams(全局变量)相关参数
		wmParams = new WindowManager.LayoutParams();
		wmParams.type = 2002;
		wmParams.flags |= 8;
		wmParams.gravity = Gravity.LEFT | Gravity.TOP; // 调整悬浮窗口至左上角
		// 以屏幕左上角为原点,设置x、y初始值
		wmParams.x = 0;
		wmParams.y = 0;
		// 设置悬浮窗口长宽数据
		wmParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
		wmParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
		wmParams.format = 1;
		
		wm.addView(view, wmParams);

		view.setOnTouchListener(new OnTouchListener() {
			public boolean onTouch(View v, MotionEvent event) {
				// 获取相对屏幕的坐标,即以屏幕左上角为原点
				x = event.getRawX();
				y = event.getRawY() - 25; // 25是系统状态栏的高度
				Log.i("currP", "currX" + x + "====currY" + y);// 调试信息
				switch (event.getAction()) {
				case MotionEvent.ACTION_DOWN:
					state = MotionEvent.ACTION_DOWN;
					StartX = x;
					StartY = y;
					// 获取相对View的坐标,即以此View左上角为原点
					mTouchStartX = event.getX();
					mTouchStartY = event.getY();
					Log.i("startP", "startX" + mTouchStartX + "====startY"
							+ mTouchStartY);// 调试信息
					break;
				case MotionEvent.ACTION_MOVE:
					state = MotionEvent.ACTION_MOVE;
					updateViewPosition();
					break;

				case MotionEvent.ACTION_UP:
					state = MotionEvent.ACTION_UP;

					updateViewPosition();
					showImg();
					mTouchStartX = mTouchStartY = 0;
					break;
				}
				return true;
			}
		});

		iv.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				Intent serviceStop = new Intent();
				serviceStop.setClass(FloatService.this, FloatService.class);
				stopService(serviceStop);
			}
		});

	}

	public void showImg() {
		if (Math.abs(x - StartX) < 1.5 && Math.abs(y - StartY) < 1.5
				&& !iv.isShown()) {
			iv.setVisibility(View.VISIBLE);
		} else if (iv.isShown()) {
			iv.setVisibility(View.GONE);
		}
	}

	private Handler handler = new Handler();
	private Runnable task = new Runnable() {
		public void run() {
			// TODO Auto-generated method stub
			dataRefresh();
			handler.postDelayed(this, delaytime);
			wm.updateViewLayout(view, wmParams);
		}
	};

	public void dataRefresh() {
		tx.setText("" + memInfo.getmem_UNUSED(this) + "KB");
		tx1.setText("" + memInfo.getmem_TOLAL() + "KB");
	}

	private void updateViewPosition() {
		// 更新浮动窗口位置参数
		wmParams.x = (int) (x - mTouchStartX);
		wmParams.y = (int) (y - mTouchStartY);
		wm.updateViewLayout(view, wmParams);
	}

	@Override
	public void onStart(Intent intent, int startId) {
		Log.d("FloatService", "onStart");
		setForeground(true);
		super.onStart(intent, startId);
	}

	@Override
	public void onDestroy() {
		handler.removeCallbacks(task);
		Log.d("FloatService", "onDestroy");
		wm.removeView(view);
		super.onDestroy();
	}

	@Override
	public IBinder onBind(Intent intent) {
		return null;
	}	
}

其主要功能部分在creatView方法里:

private void createView() {
		// 获取WindowManager
		wm = (WindowManager) getApplicationContext().getSystemService("window");
		// 设置LayoutParams(全局变量)相关参数
		wmParams = new WindowManager.LayoutParams();
		wmParams.type = 2002;
		wmParams.flags |= 8;
		wmParams.gravity = Gravity.LEFT | Gravity.TOP; // 调整悬浮窗口至左上角
		// 以屏幕左上角为原点,设置x、y初始值
		wmParams.x = 0;
		wmParams.y = 0;
		// 设置悬浮窗口长宽数据
		wmParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
		wmParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
		wmParams.format = 1;
		
		wm.addView(view, wmParams);

		view.setOnTouchListener(new OnTouchListener() {
			public boolean onTouch(View v, MotionEvent event) {
				// 获取相对屏幕的坐标,即以屏幕左上角为原点
				x = event.getRawX();
				y = event.getRawY() - 25; // 25是系统状态栏的高度
				Log.i("currP", "currX" + x + "====currY" + y);// 调试信息
				switch (event.getAction()) {
				case MotionEvent.ACTION_DOWN:
					state = MotionEvent.ACTION_DOWN;
					StartX = x;
					StartY = y;
					// 获取相对View的坐标,即以此View左上角为原点
					mTouchStartX = event.getX();
					mTouchStartY = event.getY();
					Log.i("startP", "startX" + mTouchStartX + "====startY"
							+ mTouchStartY);// 调试信息
					break;
				case MotionEvent.ACTION_MOVE:
					state = MotionEvent.ACTION_MOVE;
					updateViewPosition();
					break;

				case MotionEvent.ACTION_UP:
					state = MotionEvent.ACTION_UP;

					updateViewPosition();
					showImg();
					mTouchStartX = mTouchStartY = 0;
					break;
				}
				return true;
			}
		});

		iv.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				Intent serviceStop = new Intent();
				serviceStop.setClass(FloatService.this, FloatService.class);
				stopService(serviceStop);
			}
		});

	}

首先,代码里面用到了 WindowManager借口,整个Android的窗口机制是基于一个叫做 WindowManager,这个接口可以添加view到屏幕,也可以从屏幕删除view。它面向的对象一端是屏幕,另一端就是View,直接忽略我们以前的Activity或者Dialog之类的东东。其实我们的Activity或者Diolog底层的实现也是通过WindowManager,这个 WindowManager是全局的,整个系统就是这个唯一的东东。它是显示View的最底层了。(该段文字来自网络)其方法很简单,基本用到的就三个addView,removeView,updateViewLayout。另:在设置View高度和宽度的时候一个错误,即在View的构造函数中获取getWidth()和getHeight(),当一个view对象创建时,android并不知道其大小,所以getWidth()和getHeight()返回的结果是0,真正大小是在计算布局时才会计算,所以会发现一个有趣的事,即在onDraw( ) 却能取得长宽的原因。使用一下方法即可:

width = activity.getWindowManager().getDefaultDisplay().getWidth();   
height = activity.getWindowManager().getDefaultDisplay().getHeight(); 

下面是LayoutParams,设置他的属性:详情请看上一篇文章:

http://blog.csdn.net/aomandeshangxiao/article/details/7040486

在这里是设置成了所有应用程序之上,状态栏之下的形式,当移动的时候,会调用case MotionEvent.ACTION_MOVE:

下面的代码主要是:

private void updateViewPosition() {
		// 更新浮动窗口位置参数
		wmParams.x = (int) (x - mTouchStartX);
		wmParams.y = (int) (y - mTouchStartY);
		wm.updateViewLayout(view, wmParams);
	}
从新设置浮动栏的位置参数。这样就实现了拖动的功能。其内存数据是如何获取及及时更新的呢?

我们注意到了handler:

handler.postDelayed(task, delaytime);                                                                                                                                                                                                                                   private Runnable task = new Runnable() {
		public void run() {
			// TODO Auto-generated method stub
			dataRefresh();
			handler.postDelayed(this, delaytime);
			wm.updateViewLayout(view, wmParams);
		}
	};             

我们找到dataRefresh方法,delaytime是设置的1000,也就是每一秒钟更新一次数据。

	public void dataRefresh() {
		tx.setText("" + memInfo.getmem_UNUSED(this) + "KB");
		tx1.setText("" + memInfo.getmem_TOLAL() + "KB");
	}

最后,看下memInfo的定义:

public class memInfo {
		
	public static long getmem_UNUSED(Context mContext) {
		long MEM_UNUSED;
		ActivityManager am = (ActivityManager) mContext
				.getSystemService(Context.ACTIVITY_SERVICE);
		ActivityManager.MemoryInfo mi = new ActivityManager.MemoryInfo();
		am.getMemoryInfo(mi);
		MEM_UNUSED = mi.availMem / 1024;
		return MEM_UNUSED;
	}
	
	public static long getmem_TOLAL() {
		long mTotal;
		// 系统内存
		String path = "/proc/meminfo";
		// 存储器内容
		String content = null;
		BufferedReader br = null;
		try {
			br = new BufferedReader(new FileReader(path), 8);
			String line;
			if ((line = br.readLine()) != null) {
				// 采集内存信息
				content = line;
			}
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (br != null) {
				try {
					br.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		// beginIndex
		int begin = content.indexOf(':');
		// endIndex
		int end = content.indexOf('k');
		// 采集数量的内存
		content = content.substring(begin + 1, end).trim();
		// 转换为Int型
		mTotal = Integer.parseInt(content);	
		return mTotal;
	}	
}
里面只定义了两个方法,获取总内存和使用内存。


原文链接:http://blog.csdn.net/aomandeshangxiao/article/details/7040515
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