iOS11中iOS處理GIF圖片的方式

 

GIF 五部走如下 ：

 

1 從相冊中取出GIF圖的Data

2 通過騰訊的IM發送Gif圖

3 展示GIF圖

4 GIF圖URL緩存機制

5 將展示的GIF圖存到相冊中

 

 

一  從相冊中取出GIF圖中的Data 

 

1.TZImagePickerController中利用方法來獲取到gif圖片的image和asses

 

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

 

2.通過如下方法判斷是否是gif格式：

 

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

 

3.如果是gif圖片格式，通過   PHImageManager  的方法利用字段assets來獲取gif動圖的data數據

 

 

二 通過騰訊的IM發送Gif圖

 

1.將gif的數據存到臨時文件夾

 

            NSString *tempDir = NSTemporaryDirectory ();

            NSString *snapshotPath = [ NSString stringWithFormat : @"%@%3.f%@.gif" , tempDir, [ NSDate timeIntervalSinceReferenceDate ],[[ NSProcessInfo processInfo ] globallyUniqueString ]];

            NSError *err;

            NSFileManager *fileMgr = [ NSFileManager defaultManager ];

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

            {

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

            }

 

2.封裝成消息體發送

 

            TIMMessage * msg = [[ TIMMessage alloc ] init ];

            TIMImageElem * image_elem = [[ TIMImageElem alloc ] 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 . conversation sendMessage :msg succ :^() {

                @ strongify ( self );

                //IDSPostNFWithObj(kIMPartyRoomSendMessage,msg);

                [ self forceUpdataTableView ];

                NSLog ( @"ddsuccess" );

               

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

                NSLog ( @"ddfailed" );

            }];

 

 

三 展示GIF圖

 

1.在 MJPhoto 中本地路徑展示方式：

 

MJPhoto *photo = [[ MJPhoto alloc ] init ];

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

photo. photodata = data;

photo. image = [ UIImage sd_tz_animatedGIFWithData :data];

 

2.在 MJPhoto 遠程url路徑展示方式：

 

photo. image = [ UIImage sd_tz_animatedGIFWithData :[ NSData dataWithContentsOfURL :[ NSURL URLWithString :imageURL]]];

 

3.在 cell 中使用 FLAnimatedImageView 展示方式：

 

[ self . animatedImageView sd_setImageWithURL : imageURL ];

 

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

 

四 GIF圖URL緩存機制

 

1.通過 gifURL 加入緩存機制：

 

                    NSURL *newUrl = [ NSURL URLWithString :imageURL];

                    [[ SDWebImageDownloader sharedDownloader ] downloadImageWithURL :newUrl

                                                                          options : 0

                                                                         progress : nil

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

                                                                            [[[ SDWebImageManager sharedManager ] imageCache ] storeImage :image imageData :data forKey :newUrl. absoluteString toDisk : YES completion :^{

                                                                                photo. image = [ UIImage sd_tz_animatedGIFWithData :data];

                                                                                photo. photodata = data;

                                                                            }];

                                                                        }];

                }

 

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

{

    NSString *path = [[[ SDWebImageManager sharedManager ] imageCache ] defaultCachePathForKey :key];

    return [ NSData dataWithContentsOfFile :path];

}

 

 

五 將展示的GIF圖存到相冊中

 

 

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

                [[ PHPhotoLibrary sharedPhotoLibrary ] performChanges :^{

                    PHAssetResourceCreationOptions *options = [[ PHAssetResourceCreationOptions alloc ] init ];

                    [[ PHAssetCreationRequest creationRequestForAsset ] addResourceWithType : PHAssetResourceTypePhoto data :photo. photodata options :options];

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

 

                        if (success) {

                            。。。

                        }

                        else {

                            。。。

                        }

                }];

            }

            else {

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

            }

 

 

思考與行動：

 

1.寫出 Gif格式的 URL 轉換成 GIF格式的data數據類型的轉換函數

 

2.寫出 Gif格式的 UIImage 轉換成 GIF格式的data數據類型的轉換函數

 

3.寫出Gif格式的data數據類型的轉換成 GIF格式的UIImage的轉換函數

 

4.寫出 Gif格式的 Assets 轉換成 GIF格式的data數據類型的轉換函數

 

 

======

 

附錄：

 

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

    if (!data) {

        return nil ;

    }

   

    CGImageSourceRef source = CGImageSourceCreateWithData (( __bridge CFDataRef )data, NULL );

   

    size_t count = CGImageSourceGetCount (source);

   

    UIImage *animatedImage;

   

    if (count <= 1 ) {

        animatedImage = [[ UIImage alloc ] initWithData :data];

    }

    else {

        NSMutableArray *images = [ NSMutableArray array ];

       

        NSTimeInterval duration = 0.0f ;

       

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

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

            if (!image) {

                continue ;

            }

           

            duration += [ self sd_frameDurationAtIndex :i source :source];

           

            [images addObject :[ UIImage imageWithCGImage :image scale :[ UIScreen mainScreen ]. scale orientation : UIImageOrientationUp ]];

           

            CGImageRelease (image);

        }

       

        if (!duration) {

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

        }

       

        animatedImage = [ UIImage animatedImageWithImages :images duration :duration];

    }

   

    CFRelease (source);

   

    return animatedImage;

}

 

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