C＃Winforms如何调整图像大小并保存

Question

您好我想用openfiledialog打开一个图像文件并调整大小以上传到数据库，所以请帮我使用这个代码，我从一些地方获得，但我不知道如何制作它工作感谢

private void ResizeImg(double scaleFactor, Stream sourcePath, string tragetPath) 
{ 
    using (var image = System.Drawing.Image.FromStream(sourcePath)) 
    { 

     var newWidth = (int)(image.Width * scaleFactor); 
     var newHeight = (int)(image.Height * scaleFactor); 
     var resizingImg = new Bitmap(newWidth, newHeight); 
     var resizeGraph = Graphics.FromImage(resizingImg); 
     resizeGraph.CompositingQuality = CompositingQuality.HighQuality; 
     resizeGraph.SmoothingMode = SmoothingMode.HighQuality; 
     resizeGraph.InterpolationMode = InterpolationMode.HighQualityBicubic; 
     var imageRectangle = new Rectangle(0, 0, newWidth, newHeight); 
     resizeGraph.DrawImage(image, imageRectangle); 
     resizingImg.Save(targetPath, image.RawFormat); 
    } 
} 

Answer 1

没有指定源矩形和目标矩形，它不会拉伸。

变化

resizeGraph.DrawImage(image, imageRectangle); 

到

var srcRectangle = new Rectangle(0, 0, image.Width, image.Height); 
resizeGraph.DrawImage(image, imageRectangle,srcRectangle, GraphicsUnit.Pixel); 

BTW：考虑ImageFormat.Jpeg或png格式的保存，因为你不能写所有的图像格式，你可以阅读。