.NET 6使用ImageSharp给图片添加水印 - IT评测·应用市场-qidao123.com

//ImageFile为图片物理路径，如下方的注释
public async Task<ImageResult> WaterMark(string ImageFile)
{
ImageResult result = new ImageResult();
//var ImageFile = "D:\www\wwwroot\upload\5176caebc1404caa8b0b350181ae28ab.jpg";
var WaterMark = "D:\\www\\wwwroot\\watermark.png";
string FileName = Guid.NewGuid().ToString("N") + ".jpg";
string SavePath = "D:\\www\\wwwrootupload\" + FileName;
string imgurl = "/upload/"+FileName;
//为了与System.Drawing.Common有所区别，引用使用全路径
using (var image = await SixLabors.ImageSharp.Image.LoadAsync(ImageFile))
{
using (var clone = image.Clone(ctx => ctx.ApplyScalingImageWaterMark("center")))
{
await clone.SaveAsync(SavePath);
}
result.width = image.Width;
result.height = image.Height;
result.url = imgurl;
result.format = ".jpg";
result.state = true;
}
return result;
}

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public static class ImageSharpExtention
{
public static IImageProcessingContext ApplyScalingImageWaterMark(this IImageProcessingContext processingContext, string waterPosition = "center",string waterPath)
{
using (var mark_image = SixLabors.ImageSharp.Image.Load(waterPath))
{
int markWidth = mark_image.Width;
int markHeight = mark_image.Height;
var imgSize = processingContext.GetCurrentSize();
if (markWidth >= imgSize.Width || markHeight >= imgSize.Height) //对水印图片进行缩放
{
if (imgSize.Width > imgSize.Height)//横的长方形
{
markWidth = imgSize.Width / 2; //宽缩放一半
markHeight = (markWidth * imgSize.Height) / imgSize.Width;
}
else
{
markHeight = imgSize.Height / 2;
markWidth = (markHeight * imgSize.Width) / imgSize.Height;
}
mark_image.Mutate(mk => mk.Resize(markWidth, markHeight));
}
//水印图片完成成立，开始根据位置添加水印
var position = waterPosition;
if (string.IsNullOrEmpty(position))
{
position = "center";
}
position = position.ToLower();
if (string.IsNullOrEmpty(position))
{
position = "center";
}
SixLabors.ImageSharp.Point point = new SixLabors.ImageSharp.Point();
//左上
if (position.Contains("lefttop"))
{
point.X = 10;
point.Y = 10;
}
//上中
if (position.Contains("topcenter"))
{
point.X = (imgSize.Width - mark_image.Width) / 2;
point.Y = 10;
}
//右上
if (position.Contains("righttop"))
{
point.X = (imgSize.Width - mark_image.Width) - 10;
point.Y = 10;
}
//右中
if (position.Contains("rightcenter"))
{
point.X = (imgSize.Width - mark_image.Width) - 10;
point.Y = (imgSize.Height - mark_image.Height) / 2;
}
//右下
if (position.Contains("rightbottom"))
{
point.X = (imgSize.Width - mark_image.Width) - 10;
point.Y = (imgSize.Height - mark_image.Height) - 10;
}
//下中
if (position.Contains("bottomcenter"))
{
point.X = (imgSize.Width - mark_image.Width) / 2;
point.Y = (imgSize.Height - mark_image.Height) - 10;
}
//左下
if (position.Contains("leftbottom"))
{
point.X = 10;
point.Y = (imgSize.Height - mark_image.Height) - 10;
}
//左中
if (position.Contains("leftcenter"))
{
point.X = 10;
point.Y = (imgSize.Height - mark_image.Height) / 2;
}
if (position.Contains("center"))
{
point.X = (imgSize.Width - mark_image.Width) / 2;
point.Y = (imgSize.Height - mark_image.Height) / 2;
}
float opacity=(float)0.8;//设置不透明度，0-1之间
//添加水印
return processingContext.DrawImage(mark_image,point,opacity);
}
}
}

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public class ImageResult
{
/// <summary>
/// 文件名
/// </summary>
public string id { get; set; }
/// <summary>
/// 文件大小
/// </summary>
public string size { get; set; }
/// <summary>
/// 文件路径
/// </summary>
public string url { get; set; }
/// <summary>
/// 文件格式
/// </summary>
public string format { get; set; }
/// <summary>
/// 上传状态
/// </summary>
public bool state { get; set; }
/// <summary>
/// 上传消息
/// </summary>
public string msg { get; set; }
/// <summary>
/// 图片宽
/// </summary>
public int width { get; set; }
/// <summary>
/// 图片高
/// </summary>
public int height { get; set; }
}

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