ios 生成gif图片

需要引入库

#import <ImageIO/ImageIO.h>
#import <MobileCoreServices/UTCoreTypes.h>

#import <AssetsLibrary/ALAsset.h>

#import <AssetsLibrary/ALAssetsLibrary.h>

#import <AssetsLibrary/ALAssetsGroup.h>

#import <AssetsLibrary/ALAssetRepresentation.h>

/ 生成gif图片
-(void)shengChengGifImgViewAction{
    //gif的制作
    
    //获取源数据image
//    NSMutableArray *imgs = [[NSMutableArray alloc]initWithObjects:[UIImage imageNamed:@bear_1],[UIImage imageNamed:@bear_2], nil];
    
    //图像目标
    CGImageDestinationRef destination;
    
    //创建输出路径
    NSArray *document = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentStr = [document objectAtIndex:0];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *textDirectory = [documentStr stringByAppendingPathComponent:@"gif"];
    [fileManager createDirectoryAtPath:textDirectory withIntermediateDirectories:YES attributes:nil error:nil];
    NSString *path = [textDirectory stringByAppendingPathComponent:@"test101.gif"];
    
    
    NSLog(@"%@",path);
    
    //创建CFURL对象
    /*
     CFURLCreateWithFileSystemPath(CFAllocatorRef allocator, CFStringRef filePath, CFURLPathStyle pathStyle, Boolean isDirectory)
     
     allocator : 分配器,通常使用kCFAllocatorDefault
     filePath : 路径
     pathStyle : 路径风格,我们就填写kCFURLPOSIXPathStyle 更多请打问号自己进去帮助看
     isDirectory : 一个布尔值,用于指定是否filePath被当作一个目录路径解决时相对路径组件
     */
    CFURLRef url = CFURLCreateWithFileSystemPath (
                                                  kCFAllocatorDefault,
                                                  (CFStringRef)path,
                                                  kCFURLPOSIXPathStyle,
                                                  false);
    
    //通过一个url返回图像目标 kUTTypeGIF  CFStringRef

    destination = CGImageDestinationCreateWithURL(url, kUTTypeGIF, self.picArr.count, NULL);
    
    //设置gif的信息,播放间隔时间,基本数据,和delay时间
    NSDictionary *frameProperties = [NSDictionary
                                     dictionaryWithObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithFloat:0.001f], (NSString *)kCGImagePropertyGIFDelayTime, nil]
                                     forKey:(NSString *)kCGImagePropertyGIFDictionary];
    
    //设置gif信息
    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithCapacity:2];
//
    [dict setObject:[NSNumber numberWithBool:YES] forKey:(NSString*)kCGImagePropertyGIFHasGlobalColorMap];
    
    [dict setObject:(NSString *)kCGImagePropertyColorModelRGB forKey:(NSString *)kCGImagePropertyColorModel];
    
    [dict setObject:[NSNumber numberWithInt:8] forKey:(NSString*)kCGImagePropertyDepth];
    
    [dict setObject:[NSNumber numberWithInt:0] forKey:(NSString *)kCGImagePropertyGIFLoopCount];
    NSDictionary *gifProperties = [NSDictionary dictionaryWithObject:dict
                                                              forKey:(NSString *)kCGImagePropertyGIFDictionary];
    //合成gif
    for (UIImage* dImg in self.picArr)
    {
        CGImageDestinationAddImage(destination, dImg.CGImage, (__bridge CFDictionaryRef)frameProperties);
    }
    CGImageDestinationSetProperties(destination, (__bridge CFDictionaryRef)gifProperties);
    CGImageDestinationFinalize(destination);
    CFRelease(destination);
    
    
     NSLog(@"animated GIF file created at %@", path);
    
    NSData *data = [NSData dataWithContentsOfFile:path];
    
    // 保存到本地相册
    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
    [library writeImageDataToSavedPhotosAlbum:data metadata:nil completionBlock:^(NSURL *assetURL, NSError *error) {
        
        NSLog(@"Success at %@", [assetURL path] );
    }] ;
}