触屏事件

iphone ipad开发： 关于触屏事件的一些操作

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1. //轻击：
2. //需要在你的ViewController里重写几个方法：
3. //开始触摸的方法
4. - (void)touchesBegan:(NSSet *)touches
5. withEvent:(UIEvent *)event
6. {
7. messageLabel.text = @”Touches Began”;
8. [self updateLabelsFromTouches:touches];
9. }
10. //触摸取消的方法
11. - (void)touchesCancelled:(NSSet *)touches
12. withEvent:(UIEvent *)event
13. {
14. messageLabel.text = @”Touches Cancelled”;
15. [self updateLabelsFromTouches:touches];
16. }
17. //触摸结束的方法
18. - (void)touchesEnded:(NSSet *)touches
19. withEvent:(UIEvent *)event
20. {
21. messageLabel.text = @”Touches Stopped.”;
22. [self updateLabelsFromTouches:touches];
23. }
24. //触摸移动的方法
25. - (void)touchesMoved:(NSSet *)touches
26. withEvent:(UIEvent *)event
27. {
28. messageLabel.text = @”Drag Detected”;
29. [self updateLabelsFromTouches:touches];
30. }
31. //触摸－清扫：
32. //开始触摸
33. - (void)touchesBegan:(NSSet *)touches
34. withEvent:(UIEvent *)event
35. {
36. UITouch *touch = [touches anyObject];
37. gestureStartPoint = [touch locationInView:self.view];
38. }
39. //kMinimumGestureLength 最小移动长度 kMaximumVariance最大偏移长度
40. - (void)touchesMoved:(NSSet *)touches
41. withEvent:(UIEvent *)event
42. {
43. UITouch *touch = [touches anyObject];
44. CGPoint currentPosition = [touchlocationInView:self.view];
45. CGFloat deltaX = fabsf(gestureStartPoint.x - currentPosition.x);
46. CGFloat deltaY = fabsf(gestureStartPoint.y - currentPosition.y);
47. if(deltaX >= kMinimumGestureLength && deltaY <= kMaximumVariance)
48. {
49. label.text = @”Horizontal swipe detected”;
50. [self performSelector:@selector(eraseText)
51. withObject:nilafterDelay:2];
52. }
53. else if (deltaY >= kMinimumGestureLength &&
54. deltaX <= kMaximumVariance)
55. {
56. label.text = @”Vertical swipe detected”;
57. [selfperformSelector:@selector(eraseText)withObject:nilafterDelay:2];
58. }
59. }
60. //多次轻击判断，比如双击，三击等：
61. //单击动作响应事件
62. - (void)singleTap
63. {
64. singleLabel.text = @”Single Tap Detected”;
65. [selfperformSelector:@selector(eraseMe:)
66. withObject:singleLabel
67. afterDelay:1.6f];//1.6秒后执行eraseMe方法
68. }
69. //双击
70. - (void)doubleTap
71. {
72. doubleLabel.text = @”Double Tap Detected”;
73. [selfperformSelector:@selector(eraseMe:)
74. withObject:doubleLabel
75. afterDelay:1.6f];
76. }
77. //三击
78. - (void)tripleTap
79. {
80. tripleLabel.text = @”Triple Tap Detected”;
81. [selfperformSelector:@selector(eraseMe:)
82. withObject:tripleLabel
83. afterDelay:1.6f];
84. }
85. //四击
86. - (void)quadrupleTap
87. {
88. quadrupleLabel.text = @”Quadruple Tap Detected”;
89. [selfperformSelector:@selector(eraseMe:)
90. withObject:quadrupleLabel
91. afterDelay:1.6f];
92. }
93. - (void)eraseMe:(UITextField *)textField
94. {
95. textField.text = @"";
96. }
97. - (void)touchesBegan:(NSSet *)touches
98. withEvent:(UIEvent *)event
99. {
100. UITouch *touch = [touches anyObject];   //实例一个uitouch
101. NSUInteger tapCount = [touch tapCount]; //计算touch的tapCount次数
102. switch (tapCount)
103. {
104. case 1:
105. [selfsingleTap];
106. break;
107. case 2:
108. [selfdoubleTap];
109. break;
110. case 3:
111. [selftripleTap];
112. break;
113. case 4:
114. [selfquadrupleTap];
115. break;
116. default:
117. break;
118. }
119. }
120. //[self performSelector:@selector(eraseMe:)withObject:singleLabel afterDelay:1.6f]中
121. //performSelector:@selector(eraseMe:)withObject:singleLabel afterDelay:1.6f方法为将来afterDelay1.6秒之后调用eraseMe方法
122. //同样的[NSObect  cancelPreviousPerformSelector:withObject :afterDelay:];
123. //方法为取消这些将来的调用
124. //捏合操作：
125. - (void)eraseLabel
126. { //清空lable
127. label.text = @"";
128. }
129. //开始触碰
130. - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
131. {
132. if([touches count] ==2)
133. { //检测是否为两个手指触点
134. NSArray *twoTouches = [touchesallObjects];
135. UITouch *first = [twoTouchesobjectAtIndex:0];
136. UITouch *second = [twoTouchesobjectAtIndex:1];
137. initialDistance = distanceBetweenPoints(
138. [first locationInView:self.view], [secondlocationInView:self.view]);
139. }
140. }
141. //移动手指
142. - (void)touchesMoved:(NSSet *)touches
143. withEvent:(UIEvent *)event
144. {
145. if ([touches count] == 2)
146. {
147. NSArray *twoTouches = [touchesallObjects];
148. UITouch *first = [twoTouchesobjectAtIndex:0];
149. UITouch *second = [twoTouchesobjectAtIndex:1];
150. CGFloat currentDistance =distanceBetweenPoints(
151. [first locationInView:self.view],[secondlocationInView:self.view]);
152. if (initialDistance ==0)
153. {
154. initialDistance = currentDistance;//根据移动前后的坐标距离差检测是捏合的手势还是打开的手势
155. }
156. else if (currentDistance - initialDistance > kMinimumPinchDelta)
157. { //检测是否大于最小移动值kMinimumPinchDelta
158. label.text = @”Outward Pinch”;
159. [selfperformSelector:@selector(eraseLabel)
160. withObject:nil
161. afterDelay:1.6f];
162. }
163. else if (initialDistance - currentDistance > kMinimumPinchDelta)
164. {
165. label.text = @”Inward Pinch”;
166. [selfperformSelector:@selector(eraseLabel)
167. withObject:nil
168. afterDelay:1.6f];
169. }
170. }
171. }
172. //触碰结束
173. - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
174. {
175. initialDistance = 0;
176. }
177. //自定义手势“√”：
178. - (void)eraseLabel
179. {
180. label.text = @"";
181. }
182. - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
183. {
184. UITouch *touch = [touches anyObject];
185. CGPoint point = [touch locationInView:self.view];
186. lastPreviousPoint = point;
187. lastCurrentPoint = point;
188. lineLengthSoFar = 0.0f;
189. }
190. - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
191. {
192. UITouch *touch = [touches anyObject];
193. CGPoint previousPoint = [touchpreviousLocationInView:self.view];
194. CGPoint currentPoint = [touch locationInView:self.view];
195. //计算两条线之间的角度
196. CGFloat angle = angleBetweenLines(lastPreviousPoint,
197. lastCurrentPoint,previousPoint,currentPoint);
198. //检测手势被承认的条件 kMinimumCheckMarkAngle最小角度
199. //kMaximumCheckMarkAngle最大角度
200. //kMinimumCheckMarkLength画线最小长度
201. if (angle >= kMinimumCheckMarkAngle &&
202. angle <= kMaximumCheckMarkAngle &&
203. lineLengthSoFar > kMinimumCheckMarkLength)
204. {
205. label.text = @”Checkmark”;
206. [selfperformSelector:@selector(eraseLabel)
207. withObject:nil
208. afterDelay:1.6];
209. }
210. //lineLengthSoFar,lastPreviousPoint,lastCurrentPoint重新赋值
211. lineLengthSoFar += distanceBetweenPoints(previousPoint, currentPoint);
212. lastPreviousPoint = previousPoint;
213. lastCurrentPoint = currentPoint;
214. }
215. //这里用到一个判断两条直线的角度的方法
216. //angleBetweenLines(CGPoint line1Start, CGPoint line1End, CGPoint line2Start, CGPointlin2End);
217. //给一个几何方法集的接口方法：
218. //CGPointUtils.h 头文件
219. #import <CoreGraphics/CoreGraphics.h>
220. CGFloat distanceBetweenPoints (CGPoint first,CGPoint second);
221. CGFloat angleBetweenPoints(CGPoint first, CGPoint second);
222. CGFloat angleBetweenLines(CGPoint line1Start,CGPoint line1End, CGPoint line2Start,CGPoint lin2End);
223. //.c文件 CGPointUtils.c
224. #include ”CGPointUtils.h”
225. #include <math.h>
226. #define pi 3.14159265358979323846
227. #define degreesToRadian(x) (pi * x / 180.0)
228. #define radiansToDegrees(x) (180.0 * x / pi)
229. CGFloat distanceBetweenPoints (CGPoint first,CGPoint second)
230. {
231. CGFloat deltaX = second.x - first.x;
232. CGFloat deltaY = second.y - first.y;
233. return sqrt(deltaX*deltaX + deltaY*deltaY );
234. };
235. CGFloat angleBetweenPoints(CGPoint first, CGPoint second)
236. {
237. CGFloat height = second.y - first.y;
238. CGFloat width = first.x - second.x;
239. CGFloat rads = atan(height/width);
240. returnradiansToDegrees(rads);
241. //degs = degrees(atan((top – bottom)/(right – left)))
242. }
243. CGFloat angleBetweenLines(CGPoint line1Start,CGPoint line1End, CGPoint line2Start,CGPoint line2End)
244. {
245. CGFloat a = line1End.x - line1Start.x;
246. CGFloat b = line1End.y - line1Start.y;
247. CGFloat c = line2End.x - line2Start.x;
248. CGFloat d = line2End.y - line2Start.y;
249. CGFloat rads = acos(((a*c) + (b*d)) / ((sqrt(a*a + b*b)) * (sqrt(c*c + d*d))));
250. returnradiansToDegrees(rads);
251. }