self.photoImgV.contentMode = UIViewContentModeScaleAspectFill;
self.photoImgV.clipsToBounds = YES;

// 缩放，宽度为 SCREEN_WIDTH
self.goodsDetailImgV.contentMode = UIViewContentModeScaleAspectFit;
// 网图加载成功，按比例更新高度
[self.goodsDetailImgV sd_setImageWithURL:[NSURL URLWithString:data[@"pic"]] placeholderImage:[UIImage imageNamed:@"default_image"] completed:^(UIImage * _Nullable image, NSError * _Nullable error, SDImageCacheType cacheType, NSURL * _Nullable imageURL) {[self.goodsDetailImgV mas_updateConstraints:^(MASConstraintMaker *make) {make.height.mas_equalTo( (SCREEN_WIDTH/image.size.width) * image.size.height );}];
}];

UIImage *originalImage = [UIImage imageNamed:@"sub.png"];
finalImage = [originalImage stretchableImageWithLeftCapWidth:originalImage.size.width/2 topCapHeight:0];

UIImage *originalImg = [UIImage imageNamed:@"sub"];CGFloat protectH = originalImg.size.height/2;
CGFloat protectW = originalImg.size.width/2;UIEdgeInsets protectEdg = UIEdgeInsetsMake(protectH, protectW, protectH, protectW);UIImage *finalImg = [originalImg resizableImageWithCapInsets:protectEdg resizingMode:UIImageResizingModeStretch];

scrollview.maximumZoomScale = 2.0;
scrollview.minimumZoomScale = 0.5;

scrollview.delegate = self;

imageView.tag = 101;
[scrollview addSubview:imageView];

- (nullable UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{UIImageView *imageView = [scrollView viewWithTag:101];return imageView;
}

UITapGestureRecognizer *imageTwoTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(twoTapAction:)];
imageTwoTap.numberOfTapsRequired = 2;
[scrollView addGestureRecognizer: imageTwoTap];

#define SCALE_WIDTH  60          //要放大的局部宽度大小
#define SCALE_HEIGHT 60         //要放大的局部高度大小-(void)twoTapAction:(UITapGestureRecognizer *)tap
{UIScrollView *scrollView = (UIScrollView *)tap.view;if (scrollView.zoomScale != 1.0){[scrollView setZoomScale:1.0 animated:YES];}else{CGPoint tapPoint = [tap locationInView:scrollView];[scrollView zoomToRect:CGRectMake(tapPoint.x-SCALE_WIDTH/2, tapPoint.y-SCALE_HEIGHT/2, SCALE_WIDTH, SCALE_HEIGHT) animated:YES];}
}

- (nullable UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{if ([[scrollView viewWithTag:1000] isMemberOfClass:[UIImageView class]]){return [scrollView viewWithTag:1000];}return nil;
}

SDWebImageManager *manager = [SDWebImageManager sharedManager];[manager diskImageExistsForURL:url completion:^(BOOL isInCache) {UIImage *img = nil;if (isInCache) {// 有，直接取img = [[manager imageCache] imageFromDiskCacheForKey:url.absoluteString];}else{// 无，下载}
}];

NSData *imgData = [NSData dataWithContentsOfURL:url];
UIImage *image = [[UIImage alloc] initWithData:imgData];

- (void)loadImageFromWebWithURL:(NSURL*)url
{dispatch_queue_t queue = dispatch_queue_create("test", NULL);dispatch_async(queue, ^{// 获取数据NSData *data = [NSData dataWithContentsOfURL:url];// 主线程dispatch_sync(dispatch_get_main_queue(), ^{UIImage *image = [UIImage imageWithData:data];});});
}

SDWebImageDownloader *downloader = [SDWebImageDownloader sharedDownloader];[downloader downloadImageWithURL:urloptions:SDWebImageDownloaderHighPriorityprogress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL * _Nullable targetURL) {// 进度} completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, BOOL finished) {// 完成}];

// UIImage 转换成 data、图片 保存
UIImage *img = [UIImage imageNamed:@"test"];//png格式
NSData *imageData = UIImagePNGRepresentation(img);//JEPG格式
NSData *imageData = UIImageJPEGRepresentation(img,1.0);

NSString *cashesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask,YES) firstObject];// png，data写入
[imageData writeToFile:[cashesPath stringByAppendingPathComponent:@"image1.png"] atomically:YES];// jpg，data写入
[imageData writeToFile:[cashesPath stringByAppendingPathComponent:@"image1.jpg"] atomically:YES];

NSFileManager *fileManager = [NSFileManager defaultManager];NSString *cashesPath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory,NSUserDomainMask,YES) firstObject];// 将图片保存为PNG格式
[fileManager createFileAtPath:[cashesPath stringByAppendingString:@"/image2.png"] contents:imageData attributes:nil];// 将图片保存为JPEG格式
[fileManager createFileAtPath:[cashesPath stringByAppendingString:@"/image2.jpg"] contents:imageData attributes:nil];

UIGraphicsBeginImageContextWithOptions(image.size, YES, 0);
[image drawAtPoint:CGPointZero];
image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

UIGraphicsBeginImageContextWithOptions(size, YES, 0);
[image drawInRect:CGRectMake(0, 0, size.width, size.height)];
image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

// 最大边长
#define kMaxLength                  1280.0
// JPG格式压缩质量 0 - 1
#define kJPGCompressionQuality      0.5#pragma mark - 根据宽高压缩图片
- (UIImage*)imageWithImage:(UIImage*)originalImage scaleToSize:(CGSize)finalSize{UIGraphicsBeginImageContextWithOptions(finalSize, YES, 0);[originalImage drawInRect:CGRectMake(0, 0, finalSize.width, finalSize.height)];UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();return finalImage;
}#pragma mark - 压缩一张图片 自定义最大宽高
- (UIImage*)imageWithImage:(UIImage*)originalImage maxLength:(CGFloat)maxLength{CGFloat originalImageW = originalImage.size.width;CGFloat originalImageH = originalImage.size.height;//宽高比
//    CGFloat aspectRatio = originalImageW / originalImageH;CGFloat finalImageW = originalImageW;CGFloat finalImageH = originalImageH;if(originalImageW > maxLength || originalImageH > maxLength){//超过设置的最大宽度 判断那个边最长if(originalImageW > originalImageH){//宽度大于高度finalImageW = maxLength;finalImageH = (maxLength * originalImageH)/originalImageW;}else{finalImageH = maxLength;finalImageW = (maxLength * originalImageW)/originalImageH;}}UIImage *finalImage = [self imageWithImage:originalImage scaleToSize:CGSizeMake(finalImageW, finalImageH)];NSData *finalImageData = nil;if (UIImagePNGRepresentation(finalImage) == nil) {finalImageData = UIImageJPEGRepresentation(finalImage, kJPGCompressionQuality);}else{finalImageData = UIImagePNGRepresentation(finalImage);}return [UIImage imageWithData:finalImageData];
}#pragma mark - 压缩多张图片 自定义最大宽高
- (NSArray<UIImage*>*)imageArrayWithImageArray:(NSArray<UIImage*>*)originalImageArray maxLength:(CGFloat)maxLength{NSMutableArray *finalImageArray = [NSMutableArray array];for (int i = 0; i<originalImageArray.count; i++) {UIImage *finalImage = [self imageWithImage:originalImageArray[i] maxLength:maxLength];[finalImageArray addObject:finalImage];}return finalImageArray;
}#pragma mark - 压缩一张图片 最大宽或高1280
- (UIImage*)imageWithImage:(UIImage*)image{return [self imageWithImage:image maxLength:kMaxLength];
}#pragma mark - 压缩多张图片 最大宽或高1280
- (NSArray<UIImage*>*)imageArrayWithImageArray:(NSArray<UIImage*>*)imageArr{return [self imageArrayWithImageArray:imageArr maxLength:kMaxLength];
}