对UITextField的键盘处置方法<摘抄>

对UITextField的键盘处理方法<摘抄>

1. -?(void)registerForKeyboardNotifications??
2. {??
3. ????//添加自己做为观察者，以获取键盘显示时的通知??
4. ????[[NSNotificationCenter?defaultCenter]?addObserver:self??
5. ?????????????????????????????????????????????selector:@selector(keyboardWasShown:)??
6. ?????????????????????????????????????????????????name:UIKeyboardDidShowNotification?object:nil];??
7. ????//添加自己做为观察者，以获取键盘隐藏时的通知??
8. ????[[NSNotificationCenter?defaultCenter]?addObserver:self??
9. ?????????????????????????????????????????????selector:@selector(keyboardWasHidden:)??
10. ?????????????????????????????????????????????????name:UIKeyboardDidHideNotification?object:nil];??
11. }??
12. ??
13. //?键盘出现时调用此方法??
14. -?(void)keyboardWasShown:(NSNotification*)aNotification??
15. {??
16. ????//如果键盘是显示状态，不用做重复的操作??
17. ????if?(keyboardShown)??
18. ????????return;??
19. ??????
20. ????//获得键盘通知的用户信息字典??
21. ????NSDictionary*?info?=?[aNotification?userInfo];??
22. ??????
23. ????//?取得键盘尺寸.??
24. ????NSValue*?aValue?=?[info?objectForKey:UIKeyboardBoundsUserInfoKey];??
25. ????CGSize?keyboardSize?=?[aValue?CGRectValue].size;??
26. ??????
27. ????//?重新设置scrollView的size??
28. ????CGRect?viewFrame?=?[myScrollView?frame];??
29. ????viewFrame.size.height?-=?keyboardSize.height;??
30. ????myScrollView.frame?=?viewFrame;??
31. ??????
32. ??????
33. ????//?把当前被挡住的text?field滚动到view中适当的可见位置.??
34. ????CGRect?textFieldRect?=?[activeField?frame];??
35. ????[myScrollView?scrollRectToVisible:textFieldRect?animated:YES];??
36. ??????
37. ??????
38. ????//记录当前textField的偏移量，方便隐藏键盘时，恢复textField到原来位置??
39. ????oldContentOffsetValue?=?[myScrollView?contentOffset].y;??
40. ??????
41. ????//计算textField滚动到的适当位置??
42. ????CGFloat?value?=?(activeField.frame.origin.y+myScrollView.frame.origin.y+activeField.frame.size.height?-?self.view.frame.size.height?+?keyboardSize.height)+2.0f;??
43. ??????
44. ????//value>0则表示需要滚动，小于0表示当前textField没有被挡住，不需要滚动??
45. ????if?(value?>?0)?{??
46. ????????//使textField滚动到适当位置??
47. ????????[myScrollView?setContentOffset:CGPointMake(0,?value)?animated:YES];??
48. ????????isNeedSetOffset?=?YES;//更改状态标志为需要滚动??
49. ????}??
50. ??
51. ????//更改键盘状态标志为已显示??
52. ????keyboardShown?=?YES;??
53. }??
54. ??
55. ??
56. //?键盘隐藏时调用此方法??
57. -?(void)keyboardWasHidden:(NSNotification*)aNotification??
58. {??
59. ??
60. ??????
61. ????NSDictionary*?info?=?[aNotification?userInfo];??
62. ??????
63. ????//?Get?the?size?of?the?keyboard.??
64. ????NSValue*?aValue?=?[info?objectForKey:UIKeyboardBoundsUserInfoKey];??
65. ????CGSize?keyboardSize?=?[aValue?CGRectValue].size;??
66. ??????
67. ????//?Reset?the?height?of?the?scroll?view?to?its?original?value??
68. ????CGRect?viewFrame?=?[myScrollView?frame];??
69. ????viewFrame.size.height?+=?keyboardSize.height;??
70. ????myScrollView.frame?=?viewFrame;??
71. ??????
72. ????//如果状态标志为需要滚动，则要执行textFiled复位操作??
73. ????if?(isNeedSetOffset)?{??
74. ????????//oldContentOffsetValue记录了textField原来的位置，复位即可??
75. ????????[myScrollView?setContentOffset:CGPointMake(0,?oldContentOffsetValue)?animated:YES];??
76. ????}??
77. ??
78. ????//复位状态标志??
79. ????isNeedSetOffset?=?NO;??
80. ????keyboardShown?=?NO;??
81. } ?