C# 给图像添加一层

Question

我想给一张图片添加一个带有公司logo的图层。 logo应该放在图片中心位置（透明度较低）。

我该怎么做？

- dim

Answer 1

以下是我之前制作的一个功能，可以为某些图片创建新徽章：

编辑：我设计了一个函数，它接受最大宽度和最大高度作为参数，可以无失真地调整大小。

要求：

using System.IO;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

代码

    using (Image i = Image.FromFile(HttpContext.Current.Server.MapPath(fileName)))
    {
        float imageWidth = i.PhysicalDimension.Width;
        float imageHeight = i.PhysicalDimension.Height;
        float percentage = maxWidth / imageWidth;
        float newWidth = imageWidth * percentage;
        float newHeight = imageHeight * percentage;

        if (newHeight > maxHeight)
        {
            percentage = maxHeight / newHeight;

            newWidth = newWidth * percentage;
            newHeight = newHeight * percentage;
        }

        using (Bitmap b = new Bitmap((int)newWidth, (int)newHeight))
        {
            using (Graphics g = Graphics.FromImage(b))
            {
                g.InterpolationMode = InterpolationMode.HighQualityBicubic;
                g.SmoothingMode = SmoothingMode.AntiAlias;
                g.PixelOffsetMode = PixelOffsetMode.HighQuality;
                g.CompositingQuality = CompositingQuality.HighQuality;
                g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;

                g.DrawImage(i, new Rectangle(0, 0, b.Width, b.Height));

                if (effect == "new")
                {
                    using (Image j = Image.FromFile(HttpContext.Current.Server.MapPath("/ImageEffects/") + "new.png", true))
                    {
                        g.DrawImage(j, new Rectangle(0, 0, 60, 60));

                    }
                }

                Image newImage = Image.FromHbitmap(b.GetHbitmap());

                return newImage;
            }
        }

    }
}

- REA_ANDREW