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.Net Core 中使用SkiaSharp绘制图片

发布时间 2023-07-12 16:51:49作者: 糯米白白

引入SkiaSharp nuget包

使用代码

public class SkiaSharpHelper
{
    /// <summary>
    /// 将文字加到图片上
    /// </summary>
    /// <param name="templateFilePath">模板图片路径</param>
    /// <param name="filepath">保存文件路径</param>
    /// <returns></returns>
    public static (bool result, string msg) CreateImgByTemplate(string templateFilePath,string filepath)
    {
        string msg = string.Empty;
        try
        {
            if (!File.Exists(templateFilePath))
            {
                throw new Exception("模板文件不存在");
            }

            using (var bmp = SKBitmap.Decode(templateFilePath))
            {
                //初始化画布
                var canvas = new SKCanvas(bmp);

                var paint = new SKPaint()
                {
                    Color = SKColors.White,
                    IsAntialias = true, // 抗锯齿
                    Style = SKPaintStyle.Fill,
                    //TextAlign = SKTextAlign.Center,
                    TextSize = 16f,
                    Typeface = SKTypeface.FromFamilyName("Microsoft YaHei", SKFontStyle.Bold)
                };

                int x = 30;
                int y = 30;

                canvas.DrawText("hello world!!!", x, y * (1.2f), paint);

                using (var image = SKImage.FromBitmap(bmp))
                {
                    using (var writeStream = File.OpenWrite(filepath))
                    {
                        image.Encode(SKEncodedImageFormat.Png, 80).SaveTo(writeStream); // 保存文件
                        return (true, msg);
                    }
                }
            }
        }
        catch (Exception ex)
        {
            msg = ex.ToString();
            LogHelper.WriteLog(ex);
            return (false, msg);
        }
    }

    /// <summary>
    /// 创建验证码图片
    /// </summary>
    /// <param name="filepath">保存文件路径</param>
    /// <returns></returns>
    public static (bool result, string msg) CreateImg(string filepath)
    {
        string msg = string.Empty;
        try
        {
            using (var surface = SKSurface.Create(new SKImageInfo(100, 80)))
            {
                var canvas = surface.Canvas;
                canvas.Clear(SKColors.Blue);
                var paint = new SKPaint()
                {
                    Color = SKColors.Red,
                    IsAntialias = true, // 抗锯齿
                    Style = SKPaintStyle.Fill,
                    TextAlign = SKTextAlign.Center,
                    TextSize = 16f,
                    Typeface = SKTypeface.FromFamilyName("Microsoft YaHei", SKFontStyle.Bold)
                };
                var coord = new SKPoint(50, 48);
                canvas.DrawText("my text", coord, paint);
                using (var image = surface.Snapshot())
                {
                    using (var writeStream = System.IO.File.OpenWrite(filepath))
                    {
                        image.Encode(SKEncodedImageFormat.Png, 80).SaveTo(writeStream);
                    }
                }
            }
        }
        catch (Exception ex)
        {
            msg = ex.ToString();
            LogHelper.WriteLog(ex);
            return (false, msg);
        }
    }
}