iOS 展示 gif

淡淡的烟草味﹌ 2021-12-16 18:23 231阅读 0赞

gif 图 是多张依次有连续动作的图 顺时间展示的一种动态效果图 . 有的是均匀时间更换下一张 有的 则不是均匀时间变化

1. 那么 对于均匀 时间变化的gif图 比较适合 使用 iOS 系统自带方法 imageView 的动态展示图片的方法就好

如:

NSMutableArray *array=[NSMutableArray arrayWithCapacity:0];
    for(int i=1;i   < 10;i++)
     {
       NSString *str=[NSString stringWithFormat:@"Nav_Bg%d.png",i];
       UIImage *image=[UIImage imageNamed:str];
       [array addObject:image];
     }
     UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 460)];
     imageView.animationImages=array;
     imageView.animationDuration=1.5;//duration :持续 持续时间
     imageView.animationRepeatCount=1 ;//重复次数
     [self .window addSubview:imageView];
     [imageView startAnimating];

以上code 表达的是 10张图 在 1.5的时间 只执行一次动画展示(不循环重复) 所以关键 是这个 1.5秒 需要表达10张图 正常一次执行的时间即可出现效果比较好的动画

2. 不确定时间gif

上述方法 是按照 给定的常量时间 1.5s 执行gif 时间, 这样的弊端 是 如果把当前方法作为通用的类方法的话,这个1.5s 很不科学 . 所以 下边的方法是首先计算图片的总时间长度 .再执行动画.

#import <UIKit/UIKit.h>
    @interface MotionActiveAgeGif : UIView
    {
        UIImageView *gitView;
    }
    @property (nonatomic ,strong) UIImageView *gitView;
    @property (nonatomic ,strong)UIImageView * lastGifView;
    //@property (nonatomic ,strong)NSString * gifName;
    - (instancetype)initWithName:(NSString *)gifName andFrame:(CGRect)frame ;
    @end
    
    
    
    #import "MotionActiveAgeGif.h"
    
    #import <ImageIO/ImageIO.h>
    #import <QuartzCore/CoreAnimation.h>
    
    //#define DuringTime  1.5f
    @interface MotionActiveAgeGif ()
    {
        float totalTime ;
        CADisplayLink *displayLink ;
    }
    @end
    @implementation MotionActiveAgeGif
    @synthesize gitView ;
    @synthesize lastGifView ;
    - (instancetype)initWithName:(NSString *)gifName andFrame:(CGRect)frame
    {
        self = [super init];
        if (self) {
            totalTime = 0;
            gitView = [[UIImageView alloc]initWithFrame:frame];
            lastGifView =  [[UIImageView alloc]initWithFrame:gitView.frame];
            NSURL *url = [[NSBundle mainBundle] URLForResource:[NSString stringWithFormat:@"%@.gif",gifName] withExtension:nil];
            CGImageSourceRef csf = CGImageSourceCreateWithURL((__bridge CFTypeRef) url, NULL);
            size_t const count = CGImageSourceGetCount(csf);
            UIImage *frames[count];
            CGImageRef images[count];
            
            NSMutableArray *delayTimes = [NSMutableArray array];
            for (size_t i = 0; i < count; ++i) {
                images[i] = CGImageSourceCreateImageAtIndex(csf, i, NULL);
                UIImage *image =[[UIImage alloc] initWithCGImage:images[i]];
                lastGifView.image = image ;
                frames[i] = image;
                
                //CFBridgingRelease 给予arc所有权
                NSDictionary *dict = (NSDictionary*)CFBridgingRelease(CGImageSourceCopyPropertiesAtIndex(csf, i, NULL));
                NSLog(@"kCGImagePropertyGIFDictionary %@", [dict valueForKey:(NSString*)kCGImagePropertyGIFDictionary]);
                //
                NSDictionary *gifDict = [dict valueForKey:(NSString*)kCGImagePropertyGIFDictionary];
                [delayTimes addObject:[gifDict valueForKey:(NSString*)kCGImagePropertyGIFDelayTime]];
                
                if (totalTime >= 0)
                {
                    totalTime = totalTime + [[gifDict valueForKey:(NSString*)kCGImagePropertyGIFUnclampedDelayTime] floatValue];
                }
                NSLog(@"%lf",totalTime);
    
                CFRelease(images[i]);
            }
            UIImage *const animation = [UIImage animatedImageWithImages:[NSArray arrayWithObjects:frames count:count] duration:totalTime];
            gitView.image = animation;
            gitView.animationRepeatCount =1;  //动画重复次数1  不起作用
            [gitView startAnimating];
            [self addSubview:gitView];
            self.frame = gitView.frame;
            
            [self performSelector:@selector(stopGifView) withObject:nil afterDelay:totalTime];
            CFRelease(csf);
        }
        return self;
    }
    - (void)stopGifView
    {
        [gitView removeFromSuperview];
        [self addSubview:lastGifView];
    }

转载于:https://www.cnblogs.com/someonelikeyou/p/4637134.html