怎样使用ASP.Net剪切图片，根据原图Width、原图Height、需求的Top坐标、需求Left坐标、需求的Width、需求的Height？

Question

在服务器上我有一种宽500px，高400px的图片，现在我要利用ASP.Net剪切图片，已知X坐标为20px、Y坐标为20px，目的是得到一个宽为100px，高为100px的图片，请问代码怎么写？

---

努力！奋斗

Answer 1

原理就是：客户端使用js选择区域。将这些数据提交，然后服务器gdi+切割

private static Image cropImage( Image img, Rectangle cropArea)
{
   Bitmap bmpImage = new Bitmap ( img) ;
   Bitmap bmpCrop = bmpImage.Clone ( cropArea, bmpImage.PixelFormat ) ;
   return ( Image ) ( bmpCrop) ;
}

---

【孟子E章】

Answer 2

网上有很多例子

//Namespace Reference
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

/// <summary>
/// method for cropping an image.
/// </summary>
/// <param name="img">the image to crop</param>
/// <param name="width">new height</param>
/// <param name="height">new width</param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public Image Crop(string img, int width, int height, int x, int y)
{
    try
    {
        Image image = Image.FromFile(img);
        Bitmap bmp = new Bitmap(width, height, PixelFormat.Format24bppRgb);
        bmp.SetResolution(80, 60);

        Graphics gfx = Graphics.FromImage(bmp);
        gfx.SmoothingMode = SmoothingMode.AntiAlias;
        gfx.InterpolationMode = InterpolationMode.HighQualityBicubic;
        gfx.PixelOffsetMode = PixelOffsetMode.HighQuality;
        gfx.DrawImage(image, new Rectangle(0, 0, width, height), x, y, width, height, GraphicsUnit.Pixel);
        // Dispose to free up resources
        image.Dispose();
        bmp.Dispose();
        gfx.Dispose();

        return bmp;
    }
    catch (Exception ex)
    {
      
        return null;
    }           
}

---

【孟子E章】

Answer 3

我这样调用，怎么不能将图片保存到服务器的硬盘呢？

        string physicalImagePath = Server.MapPath("~/images/users/1001.jpg");
        FileStream fs = new FileStream(Server.MapPath("~/images/users/AAA.jpg"), FileMode.Create, FileAccess.Write);
        System.Drawing.Image resultImage = Crop(physicalImagePath, imageWidth, imageHeight, imageLeft, imageTop);
        
        resultImage.Save(fs,System.Drawing.Imaging.ImageFormat.Jpeg);
        resultImage.Dispose();

请高手指点？

---

努力！奋斗

Answer 4

刚才在网上查了一些资料，现在解决了。

谢谢孟老师。

---

努力！奋斗