生成验证码

/// <summary>
/// 生成二维码
/// </summary>
/// <param name="webRootPath">wwwroot目录</param>
/// <param name="verifyCode">验证码</param>
/// <param name="width">图片宽度</param>
/// <param name="height">图片高度</param>
/// <returns></returns>
public static byte[] CreateByteByImgVerifyCode(string webRootPath, string verifyCode, int width = 120, int height = 50)
{using Image image = new Image<Rgba32>(width, height);//漆底色白色image.Mutate(x => x.DrawLine(Pens.DashDot(Color.White, width), new PointF[] { new PointF() { X = 0, Y = 0 }, new PointF() { X = width, Y = height } }));FontCollection collection = new();FontFamily family = collection.Add(Path.Combine(webRootPath, "fonts", "FZHTJW.TTF"));Font font = family.CreateFont(20, FontStyle.Bold);PointF startPointF = new PointF(5, 5);Random random = new Random(); //随机数产生器Color[] colors = new Color[] { Color.Red, Color.Blue, Color.Green, Color.Purple, Color.Peru, Color.LightSeaGreen, Color.Lime, Color.Magenta, Color.Maroon, Color.MediumBlue, Color.MidnightBlue, Color.Navy };//绘制大小for (int i = 0; i < verifyCode.Length; i++){image.Mutate(x => x.DrawText(verifyCode[i].ToString(), font, colors[random.Next(colors.Length)], startPointF));startPointF.X += (int)(width - 10) / verifyCode.Length;startPointF.Y = random.Next(5, 10);}var pen = Pens.DashDot(Color.Silver, 1);//绘制干扰线for (var k = 0; k < 30; k++){PointF[] points = new PointF[2];points[0] = new PointF(random.Next(width), random.Next(height));points[1] = new PointF(random.Next(width), random.Next(height));image.Mutate(x => x.DrawLine(pen, points));}using MemoryStream stream = new MemoryStream();image.Save(stream, PngFormat.Instance);//输出图片流  return stream.ToArray();
}

压缩图片

/// <summary>
/// 生成缩略图并保存
/// </summary>
/// <param name="sFile">原图路径</param>
/// <param name="dFile">生成的缩略图路径</param>
/// <param name="dHeight">缩略图高度</param>
/// <param name="dWidth">缩略图宽度</param>
/// <param name="flag">压缩质量1-100</param>
/// <returns></returns>
public static bool GetPicThumbnail(string sFile, string dFile, int dHeight, int dWidth, int flag)
{Image sourceImage = null;FileStream compressImageFile = null;try{sourceImage = Image.Load(sFile);if (sourceImage == null){return false;}var originWidth = sourceImage.Width;var originHeight = sourceImage.Height;if (dWidth <= 0 && dHeight <= 0){//如果都是0就是原图dWidth = originWidth;dHeight = originHeight;}int sW;int sH;//按比例缩放if (originWidth > dWidth || originHeight > dHeight){if ((originWidth * dHeight) > (originHeight * dWidth)){sW = dWidth;sH = (dWidth * originHeight) / originWidth;}else{sH = dHeight;sW = (originWidth * dHeight) / originHeight;}}else{sW = originWidth;sH = originHeight;}缩放并且换转为灰度图//image.Mutate(x => x//         .Resize(image.Width / 2, image.Height / 2)  // 缩放//         .Grayscale());  // 转灰度图sourceImage.Mutate(x => x.Resize(sW, sH));//获取编码器var iamgeFormat = sourceImage.Metadata.DecodedImageFormat;IImageEncoder encoder = null;switch (iamgeFormat.Name.ToLower()){case "png":case "gif":case "bmp":break;default:encoder = new JpegEncoder(){Quality = flag //Use variable to set between 5-30 based on your requirements};break;}compressImageFile = new FileStream(dFile, FileMode.CreateNew, FileAccess.Write);if(encoder!=null){sourceImage.Save(compressImageFile, encoder);}else{sourceImage.Save(compressImageFile, iamgeFormat);}return true;}catch{return false;}finally{compressImageFile?.Dispose();sourceImage?.Dispose();}
}/// <summary>
/// 生成缩略图并返回byte数组
/// </summary>
/// <param name="sFile">原图路径</param>
/// <param name="dHeight">缩略图高度</param>
/// <param name="dWidth">缩略图宽度</param>
/// <param name="flag">压缩质量1-100</param>
/// <returns></returns>
public static byte[]? GetPicThumbnail(string sFile, int dHeight, int dWidth, int flag)
{Image sourceImage = null;MemoryStream compressImageFile = null;try{sourceImage = Image.Load(sFile);if (sourceImage == null){return null;}var originWidth = sourceImage.Width;var originHeight = sourceImage.Height;if (dWidth <= 0 && dHeight <= 0){//如果都是0就是原图dWidth = originWidth;dHeight = originHeight;}int sW;int sH;//按比例缩放if (originWidth > dWidth || originHeight > dHeight){if ((originWidth * dHeight) > (originHeight * dWidth)){sW = dWidth;sH = (dWidth * originHeight) / originWidth;}else{sH = dHeight;sW = (originWidth * dHeight) / originHeight;}}else{sW = originWidth;sH = originHeight;}sourceImage.Mutate(x => x.Resize(sW, sH));//获取编码器//获取编码器var iamgeFormat = sourceImage.Metadata.DecodedImageFormat;IImageEncoder encoder = null;switch (iamgeFormat.Name.ToLower()){case "png":case "gif":case "bmp":break;default:encoder = new JpegEncoder(){Quality = flag //Use variable to set between 5-30 based on your requirements};break;}compressImageFile = new MemoryStream();if (encoder != null){sourceImage.Save(compressImageFile, encoder);}else{sourceImage.Save(compressImageFile, iamgeFormat);}return compressImageFile.ToArray();}catch{return null;}finally{compressImageFile?.Dispose();sourceImage?.Dispose();}
}

生成海报

https://blog.csdn.net/qq_36437991/article/details/133383006

生成二维码

还需要依赖于QRCode库

有一个和image-sharp深度继承的库，它是跨平台的，不过目前最新版的qrcode应该也是跨平台的

/// <summary>
/// 将二维码转化为base64格式
/// </summary>
/// <param name="content">二维码内容</param>
/// <param name="iconPath">logo图片地址</param>
/// <returns></returns>
public string ToBase64QRCode(string content, string iconPath)
{QRCodeGenerator qrGenerator = new QRCodeGenerator();QRCodeData qrCodeData = qrGenerator.CreateQrCode(content, QRCodeGenerator.ECCLevel.H);var qrCode = new BitmapByteQRCode(qrCodeData);var qrCodeImage = qrCode.GetGraphic(5);if (string.IsNullOrEmpty(iconPath)){var res = Convert.ToBase64String(qrCodeImage);return res;}var iconImg = Image.Load(iconPath);iconImg.Mutate(x => x.Resize(60, 60, KnownResamplers.Box));var qrcodeImg = Image.Load(qrCodeImage);var left = qrcodeImg.Width / 2 - iconImg.Width / 2;var top = qrcodeImg.Height / 2 - iconImg.Height / 2;qrcodeImg.Mutate(t => t.DrawImage(iconImg, new Point(left, top), 1f));var qrcodeStream = new MemoryStream();qrcodeImg.Save(qrcodeStream, new PngEncoder());return Convert.ToBase64String(qrcodeStream.ToArray());
}