iOS11中iOS处理GIF图片的方式

 

GIF 五部走如下 ：

 

1 从相册中取出GIF图的Data

2 通过腾讯的IM发送Gif图

3 展示GIF图

4 GIF图URL缓存机制

5 将展示的GIF图存到相册中

 

 

一  从相册中取出GIF图中的Data 

 

1.TZImagePickerController中利用方法来获取到gif图片的image和asses

 

- (void)imagePickerController:(TZImagePickerController *)picker didFinishPickingGifImage:(UIImage *)animatedImage sourceAssets:(id)asset

 

2.通过如下方法判断是否是gif格式：

 

if ([[asset valueForKey:@"filename"] tz_containsString:@"GIF"]) 

 

3.如果是gif图片格式，通过  PHImageManager  的方法利用字段assets来获取gif动图的data数据

 

 

二 通过腾讯的IM发送Gif图

 

1.将gif的数据存到临时文件夹

 

            NSString *tempDir = NSTemporaryDirectory();

            NSString *snapshotPath = [NSStringstringWithFormat:@"%@%3.f%@.gif", tempDir, [NSDatetimeIntervalSinceReferenceDate],[[NSProcessInfoprocessInfo] globallyUniqueString]];

            NSError *err;

            NSFileManager *fileMgr = [NSFileManagerdefaultManager];

            if (![fileMgr createFileAtPath:snapshotPath contents:imageData attributes:nil])

            {

                DebugLog(@"Upload Image Failed: fail to create uploadfile: %@", err);

            }

 

2.封装成消息体发送

 

            TIMMessage * msg = [[TIMMessagealloc] init];

            TIMImageElem * image_elem = [[TIMImageElemalloc] init];

           

            image_elem.path = snapshotPath;

            image_elem.format = TIM_IMAGE_FORMAT_GIF;

            image_elem.level = TIM_IMAGE_COMPRESS_ORIGIN;

            [msg addElem:image_elem];

 

 

                       @weakify(self);

            [self.conversationsendMessage:msg succ:^() {

                @strongify(self);

                //IDSPostNFWithObj(kIMPartyRoomSendMessage,msg);

                [selfforceUpdataTableView];

                NSLog(@"ddsuccess");

               

            } fail:^(int code, NSString *err) {

                NSLog(@"ddfailed");

            }];

 

 

三 展示GIF图

 

1.在 MJPhoto 中本地路径展示方式：

 

MJPhoto *photo = [[MJPhotoalloc] init];

NSData *data = [NSDatadataWithContentsOfFile:picModel.picPath];

photo.photodata = data;

photo.image = [UIImagesd_tz_animatedGIFWithData:data];

 

2.在 MJPhoto 远程url路径展示方式：

 

photo.image = [UIImagesd_tz_animatedGIFWithData:[NSDatadataWithContentsOfURL:[NSURLURLWithString:imageURL]]];

 

3.在 cell 中使用 FLAnimatedImageView 展示方式：

 

[self.animatedImageViewsd_setImageWithURL:imageURL];

 

Ps：前提是需要更新SDWebImage版本，需要有 FLAnimatedImageView+WebCache 文件

 

四 GIF图URL缓存机制

 

1.通过 gifURL 加入缓存机制：

 

                    NSURL *newUrl = [NSURLURLWithString:imageURL];

                    [[SDWebImageDownloadersharedDownloader] downloadImageWithURL:newUrl

                                                                          options:0

                                                                         progress:nil

                                                                        completed:^(UIImage *image, NSData *data, NSError *error, BOOL finished) {

                                                                            [[[SDWebImageManagersharedManager] imageCache] storeImage:image imageData:data forKey:newUrl.absoluteStringtoDisk:YEScompletion:^{

                                                                                photo.image = [UIImagesd_tz_animatedGIFWithData:data];

                                                                                photo.photodata = data;

                                                                            }];

                                                                        }];

                }

 

- (NSData *)imageDataFromDiskCacheWithKey:(NSString *)key

{

    NSString *path = [[[SDWebImageManagersharedManager] imageCache] defaultCachePathForKey:key];

    return [NSDatadataWithContentsOfFile:path];

}

 

 

五 将展示的GIF图存到相册中

 

 

            if ([UIDevicecurrentDevice].systemVersion.floatValue >= 9.0f) {

                [[PHPhotoLibrarysharedPhotoLibrary] performChanges:^{

                    PHAssetResourceCreationOptions *options = [[PHAssetResourceCreationOptionsalloc] init];

                    [[PHAssetCreationRequestcreationRequestForAsset] addResourceWithType:PHAssetResourceTypePhotodata:photo.photodataoptions:options];

                } completionHandler:^(BOOL success, NSError * _Nullable error) 

 

                        if (success) {

                            。。。

                        }

                        else {

                            。。。

                        }

                }];

            }

            else {

                UIImageWriteToSavedPhotosAlbum(photo.image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);

            }

 

 

思考与行动：

 

1.写出 Gif格式的 URL 转换成 GIF格式的data数据类型的转换函数

 

2.写出 Gif格式的 UIImage 转换成 GIF格式的data数据类型的转换函数

 

3.写出Gif格式的data数据类型的转换成 GIF格式的UIImage的转换函数

 

4.写出 Gif格式的 Assets 转换成 GIF格式的data数据类型的转换函数

 

 

======

 

附录：

 

+ (UIImage *)sd_tz_animatedGIFWithData:(NSData *)data {

    if (!data) {

        returnnil;

    }

   

    CGImageSourceRef source = CGImageSourceCreateWithData((__bridgeCFDataRef)data, NULL);

   

    size_t count = CGImageSourceGetCount(source);

   

    UIImage *animatedImage;

   

    if (count <= 1) {

        animatedImage = [[UIImagealloc] initWithData:data];

    }

    else {

        NSMutableArray *images = [NSMutableArrayarray];

       

        NSTimeInterval duration = 0.0f;

       

        for (size_t i = 0; i < count; i++) {

            CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);

            if (!image) {

                continue;

            }

           

            duration += [selfsd_frameDurationAtIndex:i source:source];

           

            [images addObject:[UIImageimageWithCGImage:image scale:[UIScreenmainScreen].scaleorientation:UIImageOrientationUp]];

           

            CGImageRelease(image);

        }

       

        if (!duration) {

            duration = (1.0f / 10.0f) * count;

        }

       

        animatedImage = [UIImageanimatedImageWithImages:images duration:duration];

    }

   

    CFRelease(source);

   

    return animatedImage;

}

 

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