Android懸浮窗--獲取內存

首先，得先說明，這個例子並不是我寫的，是從Android的一個帖子上面看到的，下載了他的源代碼，然後分析一下，供學習共享。（另外，對於其代碼有所修改，以便於更好的說明問題，另：同時把源代碼上傳，下載地址：

免費下載地址在 http://linux.linuxidc.com/

用戶名與密碼都是www.linuxidc.com

具體下載目錄在 /pub/Android源碼集錦/2011年/12月/Android懸浮窗--獲取內存/

一開始，我們先看一下運行效果：

其中，

這一塊就是懸浮窗，可以隨意拖動，動態顯示當前內存使用量。

下面看一下代碼是如何實現的：

懸浮窗的實現是用了一個service，為什麼要用service呢？了解service特點的大體就會明白。下面看一下：

1. public class FloatService extends Service {
3. WindowManager wm = null;
4. WindowManager.LayoutParams wmParams = null;
5. View view;
6. private float mTouchStartX;
7. private float mTouchStartY;
8. private float x;
9. private float y;
10. int state;
11. TextView tx1;
12. TextView tx;
13. ImageView iv;
14. private float StartX;
15. private float StartY;
16. int delaytime=1000;
17. @Override
18. public void onCreate() {
19. Log.d("FloatService", "onCreate");
20. super.onCreate();
21. view = LayoutInflater.from(this).inflate(R.layout.floating, null);
22. tx = (TextView) view.findViewById(R.id.memunused);
23. tx1 = (TextView) view.findViewById(R.id.memtotal);
24. tx.setText("" + memInfo.getmem_UNUSED(this) + "KB");
25. tx1.setText("" + memInfo.getmem_TOLAL() + "KB");
26. iv = (ImageView) view.findViewById(R.id.img2);
27. iv.setVisibility(View.GONE);
28. createView();
29. handler.postDelayed(task, delaytime);
30. }
32. private void createView() {
33. // 獲取WindowManager
34. wm = (WindowManager) getApplicationContext().getSystemService("window");
35. // 設置LayoutParams(全局變量）相關參數
36. wmParams = new WindowManager.LayoutParams();
37. wmParams.type = 2002;
38. wmParams.flags |= 8;
39. wmParams.gravity = Gravity.LEFT | Gravity.TOP; // 調整懸浮窗口至左上角
40. // 以屏幕左上角為原點，設置x、y初始值
41. wmParams.x = 0;
42. wmParams.y = 0;
43. // 設置懸浮窗口長寬數據
44. wmParams.width = WindowManager.LayoutParams.WRAP_CONTENT;
45. wmParams.height = WindowManager.LayoutParams.WRAP_CONTENT;
46. wmParams.format = 1;
48. wm.addView(view, wmParams);
50. view.setOnTouchListener(new OnTouchListener() {
51. public boolean onTouch(View v, MotionEvent event) {
52. // 獲取相對屏幕的坐標，即以屏幕左上角為原��
53. x = event.getRawX();
54. y = event.getRawY() - 25; // 25是系統狀態欄的高度
55. Log.i("currP", "currX" + x + "====currY" + y);// 調試信息
56. switch (event.getAction()) {
57. case MotionEvent.ACTION_DOWN:
58. state = MotionEvent.ACTION_DOWN;
59. StartX = x;
60. StartY = y;
61. // 獲取相對View的坐標，即以此View左上角為原點
62. mTouchStartX = event.getX();
63. mTouchStartY = event.getY();
64. Log.i("startP", "startX" + mTouchStartX + "====startY"
65. + mTouchStartY);// 調試信息
66. break;
67. case MotionEvent.ACTION_MOVE:
68. state = MotionEvent.ACTION_MOVE;
69. updateViewPosition();
70. break;
72. case MotionEvent.ACTION_UP:
73. state = MotionEvent.ACTION_UP;
75. updateViewPosition();
76. showImg();
77. mTouchStartX = mTouchStartY = 0;
78. break;
79. }
80. return true;
81. }
82. });
84. iv.setOnClickListener(new OnClickListener() {
85. @Override
86. public void onClick(View v) {
87. // TODO Auto-generated method stub
88. Intent serviceStop = new Intent();
89. serviceStop.setClass(FloatService.this, FloatService.class);
90. stopService(serviceStop);
91. }
92. });
94. }
96. public void showImg() {
97. if (Math.abs(x - StartX) < 1.5 && Math.abs(y - StartY) < 1.5
98. && !iv.isShown()) {
99. iv.setVisibility(View.VISIBLE);
100. } else if (iv.isShown()) {
101. iv.setVisibility(View.GONE);
102. }
103. }
105. private Handler handler = new Handler();
106. private Runnable task = new Runnable() {
107. public void run() {
108. // TODO Auto-generated method stub
109. dataRefresh();
110. handler.postDelayed(this, delaytime);
111. wm.updateViewLayout(view, wmParams);
112. }
113. };
115. public void dataRefresh() {
116. tx.setText("" + memInfo.getmem_UNUSED(this) + "KB");
117. tx1.setText("" + memInfo.getmem_TOLAL() + "KB");
118. }
120. private void updateViewPosition() {
121. // 更新浮動窗口位置參數
122. wmParams.x = (int) (x - mTouchStartX);
123. wmParams.y = (int) (y - mTouchStartY);
124. wm.updateViewLayout(view, wmParams);
125. }
127. @Override
128. public void onStart(Intent intent, int startId) {
129. Log.d("FloatService", "onStart");
130. setForeground(true);
131. super.onStart(intent, startId);
132. }
134. @Override
135. public void onDestroy() {
136. handler.removeCallbacks(task);
137. Log.d("FloatService", "onDestroy");
138. wm.removeView(view);
139. super.onDestroy();
140. }
142. @Override
143. public IBinder onBind(Intent intent) {
144. return null;
145. }
146. }