从系统相册中选择GIF图片上传到服务器

-(void)assetPickerController:(ZYQAssetPickerController *)picker didFinishPickingAssets:(NSArray *)assets
{
for (int i = 0; i < assets.count; i ++) {
ALAsset *asset = assets[i];
ALAssetRepresentation *rep = [asset defaultRepresentation];

if ([rep.UTI hasSuffix:@"gif"]) {//选中的是gif

//拼接gif的文件路径
NSString *document = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *filePath = [document stringByAppendingPathComponent:rep.filename];

BOOL fileExist = [[NSFileManager defaultManager] fileExistsAtPath:filePath];
if (!fileExist) {//选中的gif还未写入到沙盒

//把选中的gif写入到沙盒中
Byte *imageBuffer = (Byte*)malloc(rep.size);
NSUInteger bufferSize = [rep getBytes:imageBuffer fromOffset:0.0 length:rep.size error:nil];
NSData *imageData = [NSData dataWithBytesNoCopy:imageBuffer length:bufferSize freeWhenDone:YES];
[imageData writeToFile:filePath atomically:YES];
}
[_selectImages addObject:filePath];
}
}
}