iOS-加载gif图片的几种方式

1. 原生方法:

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1. UIWebView特点:加载速度略长,性能更优，播放的gif动态图更加流畅。

//动态展示GIF图片-WebView
-(void)showGifImageWithWebView{
    //读取gif图片数据
    NSData *gifData = [NSData dataWithContentsOfFile: [[NSBundle mainBundle] pathForResource:@"earthGif" ofType:@"gif"]];
    //UIWebView生成
    UIWebView *imageWebView = [[UIWebView alloc] initWithFrame:CGRectMake(112, 302, 132, 102)];
    //用户不可交互
    imageWebView.userInteractionEnabled = NO;
    //加载gif数据
    [imageWebView loadData:gifData MIMEType:@"image/gif" textEncodingName:nil baseURL:nil];
    //视图添加此gif控件
    [self.view addSubview:imageWebView];
}

2. UIImagView加载的方式更加快速,性能不如UIWebView,优点:易于扩展
   增加一个UIImageView的类别(category),增加两个方法
   UIImage+Tool.h

#import <UIKit/UIKit.h>
@interface UIImageView (Tool)
/** 解析gif文件数据的方法 block中会将解析的数据传递出来 */
-(void)getGifImageWithUrk:(NSURL *)url returnData:(void(^)(NSArray<UIImage *> * imageArray,NSArray<NSNumber *>*timeArray,CGFloat totalTime, NSArray<NSNumber *>* widths, NSArray<NSNumber *>* heights))dataBlock;
/** 为UIImageView添加一个设置gif图内容的方法： */
-(void)yh_setImage:(NSURL *)imageUrl;
@end

.m

@implementation UIImageView (Tool)
//解析gif文件数据的方法 block中会将解析的数据传递出来
-(void)getGifImageWithUrk:(NSURL *)url returnData:(void(^)(NSArray<UIImage *> * imageArray, NSArray<NSNumber *>*timeArray,CGFloat totalTime, NSArray<NSNumber *>* widths,NSArray<NSNumber *>* heights))dataBlock{
    //通过文件的url来将gif文件读取为图片数据引用
    CGImageSourceRef source = CGImageSourceCreateWithURL((CFURLRef)url, NULL);
    //获取gif文件中图片的个数
    size_t count = CGImageSourceGetCount(source);
    //定义一个变量记录gif播放一轮的时间
    float allTime=0;
    //存放所有图片
    NSMutableArray * imageArray = [[NSMutableArray alloc]init];
    //存放每一帧播放的时间
    NSMutableArray * timeArray = [[NSMutableArray alloc]init];
    //存放每张图片的宽度 （一般在一个gif文件中，所有图片尺寸都会一样）
    NSMutableArray * widthArray = [[NSMutableArray alloc]init];
    //存放每张图片的高度
    NSMutableArray * heightArray = [[NSMutableArray alloc]init];
    //遍历
    for (size_t i=0; i<count; i++) {
        CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
        [imageArray addObject:(__bridge UIImage *)(image)];
        CGImageRelease(image);
        //获取图片信息
        NSDictionary * info = (__bridge NSDictionary*)CGImageSourceCopyPropertiesAtIndex(source, i, NULL);
        CGFloat width = [[info objectForKey:(__bridge NSString *)kCGImagePropertyPixelWidth] floatValue];
        CGFloat height = [[info objectForKey:(__bridge NSString *)kCGImagePropertyPixelHeight] floatValue];
        [widthArray addObject:[NSNumber numberWithFloat:width]];
        [heightArray addObject:[NSNumber numberWithFloat:height]];
        NSDictionary * timeDic = [info objectForKey:(__bridge NSString *)kCGImagePropertyGIFDictionary];
        CGFloat time = [[timeDic objectForKey:(__bridge NSString *)kCGImagePropertyGIFDelayTime]floatValue];
        allTime+=time;
        [timeArray addObject:[NSNumber numberWithFloat:time]];
    }
    dataBlock(imageArray,timeArray,allTime,widthArray,heightArray);
}
//为UIImageView添加一个设置gif图内容的方法：
-(void)yh_setImage:(NSURL *)imageUrl{
    __weak id __self = self;
    [self getGifImageWithUrk:imageUrl returnData:^(NSArray<UIImage *> *imageArray, NSArray<NSNumber *> *timeArray, CGFloat totalTime, NSArray<NSNumber *> *widths, NSArray<NSNumber *> *heights) {
        //添加帧动画
        CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"contents"];
        NSMutableArray * times = [[NSMutableArray alloc]init];
        float currentTime = 0;
        //设置每一帧的时间占比
        for (int i=0; i<imageArray.count; i++) {
            [times addObject:[NSNumber numberWithFloat:currentTime/totalTime]];
            currentTime+=[timeArray[i] floatValue];
        }
        [animation setKeyTimes:times];
        [animation setValues:imageArray];
        [animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
        //设置循环
        animation.repeatCount= MAXFLOAT;
        //设置播放总时长
        animation.duration = totalTime;
        //Layer层添加
        [[(UIImageView *)__self layer]addAnimation:animation forKey:@"gifAnimation"];
    }];
}
@end

在加载gif的地方使用导入 UIImageView+Tool

-(void)showGifImageWithImageView{
    UIImageView * imageView = [[UIImageView alloc]initWithFrame:CGRectMake(112, 342, 132, 102)];
    NSURL * url = [[NSURL alloc]initFileURLWithPath:[[NSBundle mainBundle] pathForResource:@"earthGif.gif" ofType:nil]];
    [imageView yh_setImage:url];
    [self.view addSubview:imageView];
}

2. 第三方:

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1. YLGIFImagegithub

#import "YLGIFImage.h"
#import "YLImageView.h"
-(void)showGifImageWithYLImageView{
    YLImageView* imageView = [[YLImageView alloc] initWithFrame:CGRectMake(112, 342, 132, 102)];
    CGFloat centerX = self.view.center.x;
    [imageView setCenter:CGPointMake(centerX, 402)];
    [self.view addSubview:imageView];
    imageView.image = [YLGIFImage imageNamed:@"earthGif.gif"];
}

2. FLAnimatedImagegithub

-(void)showGifImageWithFLAnimatedImage{
    //GIF 转 NSData
    //Gif 路径
    NSString *pathForFile = [[NSBundle mainBundle] pathForResource: @"earthGif" ofType:@"gif"];
    //转成NSData
    NSData *dataOfGif = [NSData dataWithContentsOfFile: pathForFile];
    //初始化FLAnimatedImage对象
    FLAnimatedImage *image = [FLAnimatedImage animatedImageWithGIFData:dataOfGif];
    //初始化FLAnimatedImageView对象
    FLAnimatedImageView *imageView = [[FLAnimatedImageView alloc] init];
    //设置GIF图片
    imageView.animatedImage = image;
    imageView.frame = CGRectMake(112, 342, 132, 102);
    [self.view addSubview:imageView];
}