iOS GIF图片处理汇总

前言

现在做项目要新加gif的上传，显示和保存到相册，之前以为挺简单的就改个后缀，💔💔💔

gif的上传

1.从相册获取gif图片

先判断获取的图片中有没有gif进行不同的业务逻辑处理，比如图片会加滤镜之类的

 [WJTZImageManager showGifImagePhotoWithController:self count:9 finishBlock:^(NSArray<UIImage *> *photos, NSArray *assets, BOOL isSelectOriginalPhoto) {
               
                if ([WJTZImageManager haveGifWithAssetArray:assets]) {
                    [myself gotoSayPublishControllerWithImageArray:photos assetArray:assets type:MouoPublishSayType];
                }else {
                    [myself gotoFilterControllerWithImageArray:photos assetArray:assets type:MouoPublishSayType];
                }
               
            }];

2.NSData数据上传

1.系统自带的UIImage里面转成NSData类型就不是图了所以我们要用以下的转换方法

- (void)getOriginalPhotoDataWithAsset:(id)asset completion:(void (^)(NSData *data,NSDictionary *info,BOOL isDegraded))completion {
    if ([asset isKindOfClass:[PHAsset class]]) {
        PHImageRequestOptions *option = [[PHImageRequestOptions alloc] init];
        option.networkAccessAllowed = YES;
        option.resizeMode = PHImageRequestOptionsResizeModeFast;
        [[PHImageManager defaultManager] requestImageDataForAsset:asset options:option resultHandler:^(NSData *imageData, NSString *dataUTI, UIImageOrientation orientation, NSDictionary *info) {
            BOOL downloadFinined = (![[info objectForKey:PHImageCancelledKey] boolValue] && ![info objectForKey:PHImageErrorKey]);
            if (downloadFinined && imageData) {
                if (completion) completion(imageData,info,NO);
            }
        }];
    } else if ([asset isKindOfClass:[ALAsset class]]) {
        ALAsset *alAsset = (ALAsset *)asset;
        ALAssetRepresentation *assetRep = [alAsset defaultRepresentation];
        Byte *imageBuffer = (Byte *)malloc(assetRep.size);
        NSUInteger bufferSize = [assetRep getBytes:imageBuffer fromOffset:0.0 length:assetRep.size error:nil];
        NSData *imageData = [NSData dataWithBytesNoCopy:imageBuffer length:bufferSize freeWhenDone:YES];
        if (completion) completion(imageData,nil,NO);
    }
}

2.由于是异步的，需要线程同步，我这些了一个方法

+ (void)getDataWithArray:(NSArray *)array finish:(void(^)(NSArray *array))finish {
    
    NSMutableArray *dataArray = [NSMutableArray array];
    NSMutableArray *assetArray = [NSMutableArray array];
    [array enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        if ([obj isKindOfClass:[UIImage class]]) {
            [dataArray addObject:UIImageJPEGRepresentation(obj, 0.8)];
        }
        if ([obj isKindOfClass:[NSData class]]) {
            [dataArray addObject:obj];
        }
        if ([obj isKindOfClass:[PHAsset class]]) {
            [assetArray addObject:obj];
        }
        
    }];
    dispatch_group_t group = dispatch_group_create();
    [assetArray enumerateObjectsUsingBlock:^(PHAsset *  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        
            dispatch_group_enter(group);
        [[TZImageManager manager] getOriginalPhotoDataWithAsset:obj completion:^(NSData *data, NSDictionary *info, BOOL isDegraded) {

            [dataArray addObject:data];
            dispatch_group_leave(group);
        }];
    }];
    dispatch_group_notify(group, dispatch_get_global_queue(0, 0), ^{
        
        finish(dataArray);
    });
    
}

3.拿着数据进行上传就行了，最好名称后缀再做个判断是GIF的上传的时候后缀改为.gif，这样的话，如果项目有需要判断GIF的情况可用地址后缀判断

gif保存到本地相册

1.获取网络请求后的NSData

现在网络请请求加载图片一般用SDWebImage和YYWebImage
这边举例YYWebImage
1.使用YYImageCache,传入网络图片地址获取图片缓存

- (nullable NSData *)getImageDataForKey:(NSString *)key;
- (void)getImageDataForKey:(NSString *)key
                 withBlock:(void(^)(NSData * _Nullable imageData))block;

2.使用YYAnimatedImageView播放GIF的话可以直接抓出NSData数据

YYImage *image = (YYImage *)imageView.image;
//image.animatedImageData
//@property (nullable, nonatomic, readonly) NSData *animatedImageData;

2.将NSData保存到本地相册

- (void)savePhotoWithData:(NSData *)data completion:(void (^)(NSError *error))completion {
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{

        PHAssetResourceCreationOptions *options = [[PHAssetResourceCreationOptions alloc] init];
        options.shouldMoveFile = YES;
        PHAssetCreationRequest *request = [PHAssetCreationRequest creationRequestForAsset];
        [request addResourceWithType:PHAssetResourceTypePhoto data:data options:options];
        request.creationDate = [NSDate date];
        
    } completionHandler:^(BOOL success, NSError * _Nullable error) {
        dispatch_sync(dispatch_get_main_queue(), ^{
            if (success && completion) {
                completion(nil);
            } else if (error) {
                NSLog(@"保存照片出错:%@",error.localizedDescription);
                if (completion) {
                    completion(error);
                }
            }
        });
    }];
}

gif的显示

网上很多第三方框架，这边推荐一个YYAnimatedImageView

gif的压缩

http://www.jianshu.com/p/867f96ffa136