using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Formats;
using SixLabors.ImageSharp.Processing;

/// <summary>/// 合并图片 小图片放在大图片上面/// </summary>/// <param name="TempleBase64Str">模板大图片base64</param>/// <param name="OutputBase64Str">模板小图片base64</param>/// <param name="x">X坐标</param>/// <param name="y">y坐标</param>/// <returns></returns>public ImageResponse MergeImage(string TempleBase64Str, string OutputBase64Str, int x, int y){string strRet = null;if (string.IsNullOrEmpty(TempleBase64Str)){return new ImageResponse { success = false, errmsg = "请传入模板大图片base64" };}if (string.IsNullOrEmpty(OutputBase64Str)){return new ImageResponse { success = false, errmsg = "请传入模板小图片base64" };}if (x < 0 || y < 0){return new ImageResponse { success = false, errmsg = "坐标不能传入负数" };}try{byte[] templebytes = Convert.FromBase64String(TempleBase64Str);byte[] outputbytes = Convert.FromBase64String(OutputBase64Str);IImageFormat format = null;var imagesTemle = SixLabors.ImageSharp.Image.Load(templebytes, out format);var outputImg = SixLabors.ImageSharp.Image.Load(outputbytes);if (imagesTemle.Height - (outputImg.Height + y) <= 0){return new ImageResponse { success = false, errmsg = "Y坐标高度超限" };}if (imagesTemle.Width - (outputImg.Width + x) <= 0){return new ImageResponse { success = false, errmsg = "X坐标宽度超限" };}//进行多图片处理imagesTemle.Mutate(a =>{//还是合并 a.DrawImage(outputImg, 1, new SixLabors.Primitives.Point(x, y));});strRet = imagesTemle.ToBase64String(format);return new ImageResponse { success = true, base64Str = strRet };}catch (Exception ex) {return new ImageResponse { success = false, errmsg ="报错信息"+ex.Message };}}

using (Stream fs = new MemoryStream(bytes))
//路径参数
using(FileStream streamTemple=System.IO.File.OpenRead("c/图片路径"))
using(MemoryStream output=new MemoryStream())
{...//保存图片
    imagesTemle.SaveAsJpeg(streamTemple);streamTemple.Close();...
}