两张图片的交换,以及放大缩小的动画

 

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

 

 

#import <UIKit/UIKit.h>

#define IMAGE_VIEW_1    100
#define    IMAGE_VIEW_2    101

#define BIGRECT CGRectMake(0.0f, 0.0f, 320.0f, 435.0f)
#define SMALLRECT CGRectMake(130.0f, 187.0f, 60.0f, 60.0f)

@interface ToggleView: UIView
{
    BOOL isOne;
}
@end

@implementation ToggleView

- (id) initWithFrame: (CGRect) aFrame;
{
    self = [super initWithFrame:aFrame];

    // Load both views, make them non-interactive
    UIImageView *imgView1 = [[UIImageView alloc] initWithFrame:BIGRECT];
    imgView1.image = [UIImage imageNamed:@"one.png"];
    imgView1.userInteractionEnabled = NO;
    imgView1.tag = IMAGE_VIEW_1;

    UIImageView *imgView2 = [[UIImageView alloc] initWithFrame:SMALLRECT];
    imgView2.image = [UIImage imageNamed:@"two.png"];
    imgView2.userInteractionEnabled = NO;
    imgView2.tag = IMAGE_VIEW_2;

    // image 1 is in front of image 2 to begin
    [self addSubview:imgView2];
    [self addSubview:imgView1];
    isOne = YES;

    [imgView1 release];
    [imgView2 release];

    return self;
}

- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
    // Determine which view occupies which role
    UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)];
    UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)];
    isOne = !isOne;

    // Pack all the changes into the animation block
    CGContextRef context = UIGraphicsGetCurrentContext();
    [UIView beginAnimations:nil context:context];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    [UIView setAnimationDuration:1.0];

    [big setFrame:SMALLRECT];
    [big setAlpha:0.5];
    [little setFrame:BIGRECT];
    [little setAlpha:1.0];

    [UIView commitAnimations];

    // Hide the shrunken "big" image.
    [big setAlpha:0.0f];
    [[big superview] bringSubviewToFront:big];
}
@end

@interface HelloController : UIViewController
@end

@implementation HelloController
- (void)loadView
{
    ToggleView *contentView = [[ToggleView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    contentView.backgroundColor = [UIColor whiteColor];
    self.view = contentView;
    [contentView release];
}
@end


@interface SampleAppDelegate : NSObject <UIApplicationDelegate>
@end

@implementation SampleAppDelegate
- (void)applicationDidFinishLaunching:(UIApplication *)application {
    UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    HelloController *hello = [[HelloController alloc] init];
    [window addSubview:hello.view];
    [window makeKeyAndVisible];
}
@end

int main(int argc, char *argv[])
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
    int retVal = UIApplicationMain(argc, argv, nil, @"SampleAppDelegate");
    [pool release];
    return retVal;
}

#import <UIKit/UIKit.h> #define IMAGE_VIEW_1 100 #define IMAGE_VIEW_2 101 #define BIGRECT CGRectMake(0.0f, 0.0f, 320.0f, 435.0f) #define SMALLRECT CGRectMake(130.0f, 187.0f, 60.0f, 60.0f) @interface ToggleView: UIView { BOOL isOne; } @end @implementation ToggleView - (id) initWithFrame: (CGRect) aFrame; { self = [super initWithFrame:aFrame]; // Load both views, make them non-interactive UIImageView *imgView1 = [[UIImageView alloc] initWithFrame:BIGRECT]; imgView1.image = [UIImage imageNamed:@"one.png"]; imgView1.userInteractionEnabled = NO; imgView1.tag = IMAGE_VIEW_1; UIImageView *imgView2 = [[UIImageView alloc] initWithFrame:SMALLRECT]; imgView2.image = [UIImage imageNamed:@"two.png"]; imgView2.userInteractionEnabled = NO; imgView2.tag = IMAGE_VIEW_2; // image 1 is in front of image 2 to begin [self addSubview:imgView2]; [self addSubview:imgView1]; isOne = YES; [imgView1 release]; [imgView2 release]; return self; } - (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event { // Determine which view occupies which role UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)]; UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)]; isOne = !isOne; // Pack all the changes into the animation block CGContextRef context = UIGraphicsGetCurrentContext(); [UIView beginAnimations:nil context:context]; [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; [UIView setAnimationDuration:1.0]; [big setFrame:SMALLRECT]; [big setAlpha:0.5]; [little setFrame:BIGRECT]; [little setAlpha:1.0]; [UIView commitAnimations]; // Hide the shrunken "big" image. [big setAlpha:0.0f]; [[big superview] bringSubviewToFront:big]; } @end @interface HelloController : UIViewController @end @implementation HelloController - (void)loadView { ToggleView *contentView = [[ToggleView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]]; contentView.backgroundColor = [UIColor whiteColor]; self.view = contentView; [contentView release]; } @end @interface SampleAppDelegate : NSObject <UIApplicationDelegate> @end @implementation SampleAppDelegate - (void)applicationDidFinishLaunching:(UIApplication *)application { UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; HelloController *hello = [[HelloController alloc] init]; [window addSubview:hello.view]; [window makeKeyAndVisible]; } @end int main(int argc, char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; int retVal = UIApplicationMain(argc, argv, nil, @"SampleAppDelegate"); [pool release]; return retVal; }

 

最重要的动画代码

- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
    // 這一段代碼,設定目前哪一張圖是大圖,哪一張是小圖
    UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)];
    UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)];
    isOne = !isOne;

    // 這是使用動畫的一些基本設定
    CGContextRef context = UIGraphicsGetCurrentContext();
    [UIView beginAnimations:nil context:context];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; // 設定為IN OUT的動畫
    [UIView setAnimationDuration:1.0]; // 動畫時間為一秒

    [big setFrame:SMALLRECT];
    [big setAlpha:0.5];
    [little setFrame:BIGRECT];
    [little setAlpha:1.0];

    [UIView commitAnimations];

    // Hide the shrunken "big" image.
    [big setAlpha:0.0f];
    [[big superview] bringSubviewToFront:big];
}
@end

- (void) touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event { // 這一段代碼,設定目前哪一張圖是大圖,哪一張是小圖 UIImageView *big = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_1 : IMAGE_VIEW_2)]; UIImageView *little = (UIImageView *)[self viewWithTag: (isOne ? IMAGE_VIEW_2 : IMAGE_VIEW_1)]; isOne = !isOne; // 這是使用動畫的一些基本設定 CGContextRef context = UIGraphicsGetCurrentContext(); [UIView beginAnimations:nil context:context]; [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; // 設定為IN OUT的動畫 [UIView setAnimationDuration:1.0]; // 動畫時間為一秒 [big setFrame:SMALLRECT]; [big setAlpha:0.5]; [little setFrame:BIGRECT]; [little setAlpha:1.0]; [UIView commitAnimations]; // Hide the shrunken "big" image. [big setAlpha:0.0f]; [[big superview] bringSubviewToFront:big]; } @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