现在的后台越来越懒了，本来列表里面的图片属性应该返回一个图片的URL地址。 但是奇葩的后台会返回两种，一种是图片链接，一种是视频链接、如果是视频的 话就需求自己取视频的第一帧，而且还没有字段判断该链接是图片链接还是视频链接，这也难道不到咱。实现方法如下。
代码语言：javascript复制#import "VideoHelper.h"
#import <AVFoundation/AVAsset.h>
#import <AVFoundation/AVAssetImageGenerator.h>
#import <AVFoundation/AVTime.h>
#import <SDWebImage/SDImageCache.h>
@implementation VideoHelper
(void)getVideoPreViewImageURL:(NSString *)videoURL forImageView:(BaseImageView *)imageView placeHolderImage:(UIImage *)placeHolder
{
[[SDImageCache sharedImageCache] queryCacheOperationForKey:videoURL done:^(UIImage * _Nullable image, NSData * _Nullable data, SDImageCacheType cacheType) {
//是否有缓存图片
if(image){
imageView.image = image;
}else{
//获取视频第一帧
[self getVideoFirstViewImage:videoURL forImageView:imageView placeHolderImage:placeHolder];
}
}];
}
// 获取视频第一帧
(void)getVideoFirstViewImage:(NSString *)videoURL forImageView:(BaseImageView *)imageView placeHolderImage:(UIImage *)placeHolder {
NSString *url = [NSString stringWithFormat:@"%@?flag=2",videoURL];
__block UIImage *videoImage;
dispatch_async(dispatch_get_global_queue(0, 0), ^{
AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:[NSURL URLWithString:url] options:nil];
NSParameterAssert(asset);
AVAssetImageGenerator *assetImageGenerator =[[AVAssetImageGenerator alloc] initWithAsset:asset];
assetImageGenerator.appliesPreferredTrackTransform = YES;
assetImageGenerator.apertureMode =AVAssetImageGeneratorApertureModeEncodedPixels;
CGImageRef thumbnailImageRef = NULL;
NSError *thumbnailImageGenerationError = nil;
thumbnailImageRef = [assetImageGenerator copyCGImageAtTime:CMTimeMake(0, 60)actualTime:NULL error:&thumbnailImageGenerationError];
if(!thumbnailImageRef)
NSLog(@"thumbnailImageGenerationError %@",thumbnailImageGenerationError);
videoImage = thumbnailImageRef ? [[UIImage alloc]initWithCGImage:thumbnailImageRef]: nil;
dispatch_async(dispatch_get_main_queue(), ^{
//主线程更新UI
if(videoImage){
imageView.image = videoImage;
//缓存图片
[[SDImageCache sharedImageCache] storeImage:videoImage forKey:videoURL toDisk:NO completion:^{
}];
}else{
//如果不是视频就设置图片
[imageView setImageUrl:videoURL placeholderImage:placeHolder];
}
});
});
}
@end
