iOS加载网络GIF图片和本地图片
2017-11-28 本文已影响72人
lxiaok
现在的APP不单单是讲究功能实在,还是得看颜值.
下面记录一下我最近在做一个显示GIF的功能列表的时候,遇到了一些小坑.
测试demo
主要用到的技术:
- SDWebImage
- AssetsLibrary.framework(系统自带的第三方类库)
- YYWebImage
我们做iOS开发的,一般遇到加载图片,都会想到SDWebImage这个第三方类库,然而这个第三方类库我在实现对应的代码逻辑的时候,发现并不是很好处理网络加载URLgif图片格式.
1.SDWebImage
- 传统的加载
//传统意义的加载
[imgView sd_setImageWithURL:url placeholderImage:nil completed:^(UIImage * _Nullable image, NSError * _Nullable error, SDImageCacheType cacheType, NSURL * _Nullable imageURL) {
imgView.image = image;
}];
- 加载本地
//1. 加载本地的gif图片
FLAnimatedImageView *imgView = (FLAnimatedImageView*)[cell.contentView viewWithTag:1];
imgView.contentMode = UIViewContentModeScaleAspectFit;
NSString * bundlePath = [[ NSBundle mainBundle] pathForResource: @ "gifBundle" ofType :@ "bundle"];
NSString *imgPath= [bundlePath stringByAppendingPathComponent :[NSString stringWithFormat:@"/%ld.gif", indexPath.row+1]];
NSData *imageData = [NSData dataWithContentsOfFile:imgPath];
imgView.animatedImage = [FLAnimatedImage animatedImageWithGIFData:imageData];
在调试的时候,发行加载本地的没有问题,也没有重用的现象出现,也没有卡顿.所以我们就打算采用这个加载网络URL的GIF图片.
- 加载url的gif
//2. 加载url gif 图片 (需要在故事板设置imageview的类型为FLAnimatedImageView)
FLAnimatedImageView *imageView = (FLAnimatedImageView*)[cell.contentView viewWithTag:1];
NSDictionary *dic = listArray[indexPath.row];
NSURL *url = [NSURL URLWithString:[dic valueForKey:@"GIFImageURL"]];
imageView.image = [UIImage imageNamed:@"专注.jpg"];
[self loadAnimatedImageWithURL:url completion:^(FLAnimatedImage *animatedImage) {
imageView.animatedImage = animatedImage;
}];
异步加载
- (void)loadAnimatedImageWithURL:(NSURL *const)url completion:(void (^)(FLAnimatedImage *animatedImage))completion
{
NSString *const filename = url.lastPathComponent;
NSString *const diskPath = [NSHomeDirectory() stringByAppendingPathComponent:filename];
NSData * __block animatedImageData = [[NSFileManager defaultManager] contentsAtPath:diskPath];
FLAnimatedImage * __block animatedImage = [[FLAnimatedImage alloc] initWithAnimatedGIFData:nil];
if (animatedImage) {
if (completion) {
completion(animatedImage);
}
} else {
[[[NSURLSession sharedSession] dataTaskWithURL:url completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {
animatedImageData = data;
animatedImage = [[FLAnimatedImage alloc] initWithAnimatedGIFData:animatedImageData];
if (animatedImage) {
if (completion) {
dispatch_async(dispatch_get_main_queue(), ^{
completion(animatedImage);
});
}
[data writeToFile:diskPath atomically:YES];
}
}] resume];
}
}
我们发现,按照他们的使用方法来实现的时候,发行出现稍微卡顿和重用的bug.但是我们还没放弃,我们想按照加载本地的方法来加载试试.
这个时候引入类库:AssetsLibrary
FLAnimatedImageView *imgView = (FLAnimatedImageView*)[cell.contentView viewWithTag:1];
imgView.contentMode = UIViewContentModeScaleAspectFit;
ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];
void (^ALAssetsLibraryAssetForURLResultBlock)(ALAsset *) = ^(ALAsset *asset) {
if (asset != nil) {
ALAssetRepresentation *rep = [asset defaultRepresentation];
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];
FLAnimatedImage *i = [FLAnimatedImage animatedImageWithGIFData:imageData];
imgView.animatedImage = i;
}
else {
}
};
[assetLibrary assetForURL:url
resultBlock:ALAssetsLibraryAssetForURLResultBlock
failureBlock:^(NSError *error) {
}];
*/
结果发现可以加载出来,但是GIF图片不动!!
所以我们上网查找了相关资料,发行了使用YYWebImage效果更好,更加容易实现.
PS:为什么使用FLAnimatedImageView,是因为SDWebImage之前的UIImage+GIF不在处理gif,而是交给FLAnimatedImage来处理
具体导入直接 pod 'SDWebImage/GIF'即可
FLAnimatedImage源代码
2.YYWebImage
YYWebImage使用起来很简单
pod 'YYWebImage'
在使用界面引入#import "YYWebImage.h"即可
/*
//YYWebImage 使用
YYAnimatedImageView *imageView = (YYAnimatedImageView*)[cell.contentView viewWithTag:1];
imageView.yy_imageURL = url;
*/
其中还有很多的加载方式和样式,大家有时间可以去尝试.
参考资源:
