1：原文摘自：http://mobile.51cto.com/iphone-285108.htm

iPhone开发中如何将制作图片放大缩小案例是本文要介绍的内容，主要是来学习iphone开发中动画的制作，具体内容一起来看本文详解。在IPhone SDK开发范例大全中,有很多的范例码。

下面这段范例码,示范了两张图片的交换,以及放大缩小的动画

动画效果请参照下图

1. #import <UIKit/UIKit.h>
2. #define IMAGE_VIEW_1    100
3. #define    IMAGE_VIEW_2    101
4. #define BIGRECT CGRectMake(0.0f, 0.0f, 320.0f, 435.0f)
5. #define SMALLRECT CGRectMake(130.0f, 187.0f, 60.0f, 60.0f)
6. @interface ToggleView: UIView
7. {
8. BOOL isOne;
9. }
10. @end
11. @implementation ToggleView
12. - (id) initWithFrame: (CGRect) aFrame;
13. {
14. self = [super initWithFrame:aFrame];
15. // Load both views, make them non-interactive
16. UIImageView *imgView1 = [[UIImageView alloc] initWithFrame:BIGRECT];
17. imgView1.image = [UIImage imageNamed:@"one.png"];
18. imgView1.userInteractionEnabled = NO;
19. imgView1.tag = IMAGE_VIEW_1;
20. UIImageView *imgView2 = [[UIImageView alloc] initWithFrame:SMALLRECT];
21. imgView2.image = [UIImage imageNamed:@"two.png"];
22. imgView2.userInteractionEnabled = NO;
23. imgView2.tag = IMAGE_VIEW_2;
24. // image 1 is in front of image 2 to begin
25. [self addSubview:imgView2];
26. [self addSubview:imgView1];
27. isOne = YES;
28. [imgView1 release];
29. [imgView2 release];
30. return self;
31. }
32. - (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
33. {
34. // Determine which view occupies which role
35. UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)];
36. UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)];
37. isOne = !isOne;
38. // Pack all the changes into the animation block
39. CGContextRef context = UIGraphicsGetCurrentContext();
40. [UIView beginAnimations:nil context:context];
41. [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
42. [UIView setAnimationDuration:1.0];
43. [big setFrame:SMALLRECT];
44. [big setAlpha:0.5];
45. [little setFrame:BIGRECT];
46. [little setAlpha:1.0];
47. [UIView commitAnimations];
48. // Hide the shrunken "big" image.
49. [big setAlpha:0.0f];
50. [[big superview] bringSubviewToFront:big];
51. }
52. @end
53. @interface HelloController : UIViewController
54. @end
55. @implementation HelloController
56. - (void)loadView
57. {
58. ToggleView *contentView = [[ToggleView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
59. contentView.backgroundColor = [UIColor whiteColor];
60. self.view = contentView;
61. [contentView release];
62. }
63. @end
64. @interface SampleAppDelegate : NSObject <UIApplicationDelegate>
65. @end
66. @implementation SampleAppDelegate
67. - (void)applicationDidFinishLaunching:(UIApplication *)application {
68. UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
69. HelloController *hello = [[HelloController alloc] init];
70. [window addSubview:hello.view];
71. [window makeKeyAndVisible];
72. }
73. @end
74. int main(int argc, char *argv[])
75. {
76. NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
77. int retVal = UIApplicationMain(argc, argv, nil, @"SampleAppDelegate");
78. [pool release];
79. return retVal;
80. }
81. #import <UIKit/UIKit.h>
82. #define IMAGE_VIEW_1    100
83. #define    IMAGE_VIEW_2    101
84. #define BIGRECT CGRectMake(0.0f, 0.0f, 320.0f, 435.0f)
85. #define SMALLRECT CGRectMake(130.0f, 187.0f, 60.0f, 60.0f)
86. @interface ToggleView: UIView
87. {
88. BOOL isOne;
89. }
90. @end
91. @implementation ToggleView
92. - (id) initWithFrame: (CGRect) aFrame;
93. {
94. self = [super initWithFrame:aFrame];
95. // Load both views, make them non-interactive
96. UIImageView *imgView1 = [[UIImageView alloc] initWithFrame:BIGRECT];
97. imgView1.image = [UIImage imageNamed:@"one.png"];
98. imgView1.userInteractionEnabled = NO;
99. imgView1.tag = IMAGE_VIEW_1;
100. UIImageView *imgView2 = [[UIImageView alloc] initWithFrame:SMALLRECT];
101. imgView2.image = [UIImage imageNamed:@"two.png"];
102. imgView2.userInteractionEnabled = NO;
103. imgView2.tag = IMAGE_VIEW_2;
104. // image 1 is in front of image 2 to begin
105. [self addSubview:imgView2];
106. [self addSubview:imgView1];
107. isOne = YES;
108. [imgView1 release];
109. [imgView2 release];
110. return self;
111. }
112. - (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
113. {
114. // Determine which view occupies which role
115. UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)];
116. UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)];
117. isOne = !isOne;
118. // Pack all the changes into the animation block
119. CGContextRef context = UIGraphicsGetCurrentContext();
120. [UIView beginAnimations:nil context:context];
121. [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
122. [UIView setAnimationDuration:1.0];
123. [big setFrame:SMALLRECT];
124. [big setAlpha:0.5];
125. [little setFrame:BIGRECT];
126. [little setAlpha:1.0];
127. [UIView commitAnimations];
128. // Hide the shrunken "big" image.
129. [big setAlpha:0.0f];
130. [[big superview] bringSubviewToFront:big];
131. }
132. @end
133. @interface HelloController : UIViewController
134. @end
135. @implementation HelloController
136. - (void)loadView
137. {
138. ToggleView *contentView = [[ToggleView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
139. contentView.backgroundColor = [UIColor whiteColor];
140. self.view = contentView;
141. [contentView release];
142. }
143. @end
144. @interface SampleAppDelegate : NSObject <UIApplicationDelegate>
145. @end
146. @implementation SampleAppDelegate
147. - (void)applicationDidFinishLaunching:(UIApplication *)application {
148. UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
149. HelloController *hello = [[HelloController alloc] init];
150. [window addSubview:hello.view];
151. [window makeKeyAndVisible];
152. }
153. @end
154. int main(int argc, char *argv[])
155. {
156. NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
157. int retVal = UIApplicationMain(argc, argv, nil, @"SampleAppDelegate");
158. [pool release];
159. return retVal;
160. }

最重要的动画代码

1. - (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
2. {
3. // 這一段代碼,設定目前哪一張圖是大圖,哪一張是小圖
4. UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)];
5. UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)];
6. isOne = !isOne;
7. // 這是使用動畫的一些基本設定
8. CGContextRef context = UIGraphicsGetCurrentContext();
9. [UIView beginAnimations:nil context:context];
10. [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; // 設定為IN OUT的動畫
11. [UIView setAnimationDuration:1.0]; // 動畫時間為一秒
12. [big setFrame:SMALLRECT];
13. [big setAlpha:0.5];
14. [little setFrame:BIGRECT];
15. [little setAlpha:1.0];
16. [UIView commitAnimations];
17. // Hide the shrunken "big" image.
18. [big setAlpha:0.0f];
19. [[big superview] bringSubviewToFront:big];
20. }
21. @end
22. - (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
23. {
24. // 這一段代碼,設定目前哪一張圖是大圖,哪一張是小圖
25. UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)];
26. UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)];
27. isOne = !isOne;
28. // 這是使用動畫的一些基本設定
29. CGContextRef context = UIGraphicsGetCurrentContext();
30. [UIView beginAnimations:nil context:context];
31. [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; // 設定為IN OUT的動畫
32. [UIView setAnimationDuration:1.0]; // 動畫時間為一秒
33. [big setFrame:SMALLRECT];
34. [big setAlpha:0.5];
35. [little setFrame:BIGRECT];
36. [little setAlpha:1.0];
37. [UIView commitAnimations];
38. // Hide the shrunken "big" image.
39. [big setAlpha:0.0f];
40. [[big superview] bringSubviewToFront:big];
41. }
42. @end

代码中设定透明度的目的,为了就是小图放大的时候,才不会被原本在上面的大图盖到,导致看不到图。

小结：iPhone开发中如何将制作图片放大缩小案例的内容介绍完了，希望通过本文的学习能对你有所帮助！