Android 遊戲開發 SurfaceView架構

SurfaceView和View的明顯不同在於Surface不需要通過線程來更新視圖，但在繪製之前必須使用lockCanvas方法鎖定畫布，並得
到畫布，然後繪製，完成後用unlockCanvasAndPost方法解鎖畫布。SurfaceView類的事件處理和View一樣。
繪製介面的類：

1. package com.yarin.android.Examples_05_02;<br /> 2.<br /> 3. import android.content.Context;<br /> 4. import android.graphics.Canvas;<br /> 5. import android.graphics.Color;<br /> 6. import android.graphics.Paint;<br /> 7. import android.view.SurfaceHolder;<br /> 8. import android.view.SurfaceView;<br /> 9.<br /> 10. public class GameSurfaceView extends SurfaceView<br /> 11.<br /> 12. implements SurfaceHolder.Callback,Runnable<br /> 13. {<br /> 14. //控制迴圈<br /> 15. boolean mbLoop = false;<br /> 16.<br /> 17. //定義SurfaceHolder對象<br /> 18. SurfaceHolder mSurfaceHolder = null;<br /> 19. int miCount = 0;<br /> 20. int y = 50;<br /> 21.<br /> 22.<br /> 23. public GameSurfaceView(Context context)<br /> 24. {<br /> 25. super(context);<br /> 26.<br /> 27. // 執行個體化SurfaceHolder<br /> 28. mSurfaceHolder = this.getHolder();<br /> 29.<br /> 30. // 添加回調<br /> 31. mSurfaceHolder.addCallback(this);<br /> 32. this.setFocusable(true);<br /> 33.<br /> 34. mbLoop = true;<br /> 35. }<br /> 36.<br /> 37.<br /> 38. // 在surface的大小發生改變時激發<br /> 39. public void surfaceChanged(SurfaceHolder holder, int format, int width, int height)<br /> 40. {<br /> 41.<br /> 42. }<br /> 43.<br /> 44. // 在surface建立時激發<br /> 45. public void surfaceCreated(SurfaceHolder holder)<br /> 46. {<br /> 47. //開啟繪圖線程<br /> 48. new Thread(this).start();<br /> 49. }<br /> 50.<br /> 51. // 在surface銷毀時激發<br /> 52. public void surfaceDestroyed(SurfaceHolder holder)<br /> 53. {<br /> 54. // 停止迴圈<br /> 55. mbLoop = false;<br /> 56. }<br /> 57.<br /> 58. // 繪圖迴圈<br /> 59. public void run()<br /> 60. {<br /> 61. while (mbLoop)<br /> 62. {<br /> 63. try<br /> 64. {<br /> 65. Thread.sleep(200);<br /> 66. }<br /> 67. catch (Exception e)<br /> 68. {<br /> 69.<br /> 70. }<br /> 71. synchronized( mSurfaceHolder )<br /> 72. {<br /> 73. Draw();<br /> 74. }<br /> 75.<br /> 76. }<br /> 77. }<br /> 78.<br /> 79. // 繪圖方法<br /> 80. public void Draw()<br /> 81. {<br /> 82. //鎖定畫布，得到canvas<br /> 83. Canvas canvas= mSurfaceHolder.lockCanvas();<br /> 84.<br /> 85. if (mSurfaceHolder==null || canvas == null )<br /> 86. {<br /> 87. return;<br /> 88. }<br /> 89.<br /> 90. if (miCount < 100)<br /> 91. {<br /> 92. miCount++;<br /> 93. }<br /> 94. else<br /> 95. {<br /> 96. miCount = 0;<br /> 97. }<br /> 98. // 繪圖<br /> 99. Paint mPaint = new Paint();<br /> 100. mPaint.setAntiAlias(true);<br /> 101. mPaint.setColor(Color.BLACK);<br /> 102. //繪製矩形--清屏作用<br /> 103. canvas.drawRect(0, 0, 320, 480, mPaint);<br /> 104. switch (miCount % 4)<br /> 105. {<br /> 106. case 0:<br /> 107. mPaint.setColor(Color.BLUE);<br /> 108. break;<br /> 109. case 1:<br /> 110. mPaint.setColor(Color.GREEN);<br /> 111. break;<br /> 112. case 2:<br /> 113. mPaint.setColor(Color.RED);<br /> 114. break;<br /> 115. case 3:<br /> 116. mPaint.setColor(Color.YELLOW);<br /> 117. break;<br /> 118. default:<br /> 119. mPaint.setColor(Color.WHITE);<br /> 120. break;<br /> 121. }<br /> 122.<br /> 123. canvas.drawCircle((320 - 25) / 2, y, 50, mPaint);<br /> 124. // 繪製後解鎖，繪製後必須解鎖才能顯示<br /> 125. mSurfaceHolder.unlockCanvasAndPost(canvas);<br /> 126. }<br /> 127. }