C# 在運行時調整圖像大小

Question

如果大小超過 1024x768，我想調整圖像大小，然后保存新實例而不是原始實例，但此代碼正在保存原始實例。 我該如何解決？

      private static void ResizeImage(int newWidth, int newHeight, Stream OriginalImage, string targetPath)
    {
        using (var image = System.Drawing.Image.FromStream(OriginalImage))
        {
            var thumbnailImg = new Bitmap(newWidth, newHeight);
            var thumbGraph = Graphics.FromImage(thumbnailImg);
            thumbGraph.CompositingQuality = CompositingQuality.HighQuality;
            thumbGraph.SmoothingMode = SmoothingMode.HighQuality;
            thumbGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;
            var imageRectangle = new Rectangle(0, 0, newWidth, newHeight);
            thumbGraph.DrawImage(image, imageRectangle);
            thumbnailImg.Save(targetPath, image.RawFormat);
        }
    }

Answer 1

我假設“thumbnailImg”應該是“圖像”的縮小版本。

如果是這樣 - 使用專為此目的設計的Bitmap 構造函數：

Bitmap(Image, Int32, Int32)

例如：

var thumbnail = new Bitmap(image, newWidth, newHeight);