可以在UIImage的分类中加入下面的代码,并且引入系统的ImageIO.framework
/** 根据图片的url获取尺寸 @param URL url @return CGSize */ + (CGSize)getImageSizeWithURL:(id)URL; /** * 根据图片url获取图片尺寸 */ + (CGSize)getImageSizeWithURL:(id)URL{ NSURL * url = nil; if ([URL isKindOfClass:[NSURL class]]) { url = URL; } if ([URL isKindOfClass:[NSString class]]) { url = [NSURL URLWithString:URL]; } if (!URL) { return CGSizeZero; } CGImageSourceRef imageSourceRef = CGImageSourceCreateWithURL((CFURLRef)url, NULL); CGFloat width = 0, height = 0; if (imageSourceRef) { CFDictionaryRef imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSourceRef, 0, NULL); if (imageProperties != NULL) { CFNumberRef widthNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelWidth); // if (widthNumberRef != NULL) { // CFNumberGetValue(widthNumberRef, kCFNumberFloat64Type, &width); // } // CFNumberRef heightNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight); // if (heightNumberRef != NULL) { // CFNumberGetValue(heightNumberRef, kCFNumberFloat64Type, &height); // } //判断设备是否为64位 #if defined(__LP64__) && __LP64__ if (widthNumberRef != NULL) { CFNumberGetValue(widthNumberRef, kCFNumberFloat64Type, &width); } CFNumberRef heightNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight); if (heightNumberRef != NULL) { CFNumberGetValue(heightNumberRef, kCFNumberFloat64Type, &height); } #else if (widthNumberRef != NULL) { CFNumberGetValue(widthNumberRef, kCFNumberFloat32Type, &width); } CFNumberRef heightNumberRef = CFDictionaryGetValue(imageProperties, kCGImagePropertyPixelHeight); if (heightNumberRef != NULL) { CFNumberGetValue(heightNumberRef, kCFNumberFloat32Type, &height); } #endif CFRelease(imageProperties); } CFRelease(imageSourceRef); } return CGSizeMake(width, height); }
实践证明,网上的另外一种方法是不可行存在问题的,贴上所示的图片url:http://xs3.op.xywy.com/club.xywy.com/doc/20181017/0fd2a51f9435a4.jpg
// 根据图片url获取图片尺寸 -(CGSize)getImageSizeWithURL:(id)imageURL { NSURL* URL = nil; if([imageURL isKindOfClass:[NSURL class]]){ URL = imageURL; } if([imageURL isKindOfClass:[NSString class]]){ URL = [NSURL URLWithString:imageURL]; } if(URL == nil) return CGSizeZero; // url不正确返回CGSizeZero NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:URL]; NSString* pathExtendsion = [URL.pathExtension lowercaseString]; CGSize size = CGSizeZero; if([pathExtendsion isEqualToString:@"png"]){ size = [self getPNGImageSizeWithRequest:request]; } else if([pathExtendsion isEqual:@"gif"]) { size = [self getGIFImageSizeWithRequest:request]; } else{ size = [self getJPGImageSizeWithRequest:request]; } if(CGSizeEqualToSize(CGSizeZero, size)) // 如果获取文件头信息失败,发送异步请求请求原图 { NSData* data = [NSURLConnection sendSynchronousRequest:[NSURLRequest requestWithURL:URL] returningResponse:nil error:nil]; UIImage* image = [UIImage imageWithData:data]; if(image) { size = image.size; } } return size; } // 获取PNG图片的大小 -(CGSize)getPNGImageSizeWithRequest:(NSMutableURLRequest*)request { [request setValue:@"bytes