Touch Screen

今天试了一天，在BookDetail实现public boolean onMotionEvent(MotionEvent event)
一直都没有效果！
晚上才发现，原来要实现触摸方式。必须在自己的view里面实现


贴上一个例子做为参考：

1. /*
2. *Copyright(C)2007GoogleInc.
3. *
4. *LicensedundertheApacheLicense,Version2.0(the"License");
5. *youmaynotusethisfileexceptincompliancewiththeLicense.
6. *YoumayobtainacopyoftheLicenseat
7. *
8. *http://www.apache.org/licenses/LICENSE-2.0
9. *
10. *Unlessrequiredbyapplicablelaworagreedtoinwriting,software
11. *distributedundertheLicenseisdistributedonan"ASIS"BASIS,
12. *WITHOUTWARRANTIESORCONDITIONSOFANYKIND,eitherexpressorimplied.
13. *SeetheLicenseforthespecificlanguagegoverningpermissionsand
14. *limitationsundertheLicense.
15. */
17. packagecom.google.android.samples.graphics;
19. importandroid.app.Activity;
20. importandroid.content.Context;
21. importandroid.graphics.Bitmap;
22. importandroid.graphics.Canvas;
23. importandroid.graphics.Paint;
24. importandroid.graphics.Rect;
25. importandroid.os.Bundle;
26. importandroid.view.MotionEvent;
27. importandroid.view.View;
29. //Needthefollowingimporttogetaccesstotheappresources,sincethis
30. //classisinasub-package.
33. /**
34. *Demonstratesthehandlingoftouchscreeneventstoimplementasimple
35. *paintingapp.
36. */
37. publicclassTouchPaintextendsActivity{
38. @Override
39. protectedvoidonCreate(Bundleicicle){
40. super.onCreate(icicle);
41. setContentView(newMyView(this));
42. }
44. publicclassMyViewextendsView{
45. BitmapmBitmap;
46. CanvasmCanvas;
47. privatefinalRectmRect=newRect();
48. privatefinalPaintmPaint;
49. privatebooleanmCurDown;
50. privateintmCurX;
51. privateintmCurY;
52. privatefloatmCurPressure;
53. privatefloatmCurSize;
54. privateintmCurWidth;
56. publicMyView(Contextc){
57. super(c);
58. mPaint=newPaint();
59. mPaint.setAntiAlias(true);
60. mPaint.setARGB(255,255,255,255);
61. }
63. @Override
64. protectedvoidonSizeChanged(intw,inth,intoldw,intoldh){
65. intcurW=mBitmap!=null?mBitmap.width():0;
66. intcurH=mBitmap!=null?mBitmap.height():0;
67. if(curW>=w&&curH>=h){
68. return;
69. }
71. if(curW<w)curW=w;
72. if(curH<h)curH=h;
74. BitmapnewBitmap=Bitmap.createBitmap(curW,curH,false);
75. CanvasnewCanvas=newCanvas();
76. newCanvas.setDevice(newBitmap);
77. if(mBitmap!=null){
78. newCanvas.drawBitmap(mBitmap,0,0,null);
79. }
80. mBitmap=newBitmap;
81. mCanvas=newCanvas;
82. }
84. @Override
85. protectedvoidonDraw(Canvascanvas){
86. if(mBitmap!=null){
87. canvas.drawBitmap(mBitmap,0,0,null);
88. }
89. }
91. @Override
92. publicbooleanonMotionEvent(MotionEventevent){
93. intaction=event.getAction();
94. mCurDown=action==MotionEvent.ACTION_DOWN
95. ||action==MotionEvent.ACTION_MOVE;
96. mCurX=(int)event.getX();
97. mCurY=(int)event.getY();
98. mCurPressure=event.getPressure();
99. mCurSize=event.getSize();
100. mCurWidth=(int)(mCurSize*(getWidth()/3));
101. if(mCurWidth<1)mCurWidth=1;
102. if(mCurDown&&mBitmap!=null){
103. intpressureLevel=(int)(mCurPressure*255);
104. mPaint.setARGB(pressureLevel,255,255,255);
105. mCanvas.drawCircle(mCurX,mCurY,mCurWidth,mPaint);
106. mRect.set(mCurX-mCurWidth-2,mCurY-mCurWidth-2,
107. mCurX+mCurWidth+2,mCurY+mCurWidth+2);
108. invalidate(mRect);
109. }
110. returntrue;
111. }
113. }
114. }