How to resize an image in C ＃

In this article , I'll show you how to C# To adjust the size of the image you want . To achieve this goal , We can take the following steps ：

1. First get the image you want to size ：

string path = Server.MapPath("~/Images");
System.Drawing.Image img = System.Drawing.Image.FromFile(string.Concat(path,"/3904.jpg"));

2. Convert image to Bitmap：

Bitmap b = new Bitmap(img);

3. Create a method to resize an image ：

private static System.Drawing.Image resizeImage(System.Drawing.Image imgToResize, Size size)
{
    
    // Get picture width 
    int sourceWidth = imgToResize.Width;
    // Get the height of the picture 
    int sourceHeight = imgToResize.Height;
  
    float nPercent = 0;
    float nPercentW = 0;
    float nPercentH = 0;
    // Calculate the scaling of the width 
    nPercentW = ((float)size.Width / (float)sourceWidth);
    // Calculate the scaling of the height 
    nPercentH = ((float)size.Height / (float)sourceHeight);      
  
    if (nPercentH < nPercentW)
        nPercent = nPercentH;
    else
     nPercent = nPercentW;
     // The desired width 
     int destWidth = (int)(sourceWidth * nPercent);
     // The height of expectations 
     int destHeight = (int)(sourceHeight * nPercent);
  
     Bitmap b = new Bitmap(destWidth, destHeight);
     Graphics g = Graphics.FromImage((System.Drawing.Image)b);
     g.InterpolationMode = InterpolationMode.HighQualityBicubic;
     // The plot 
     g.DrawImage(imgToResize, 0, 0, destWidth, destHeight);
     g.Dispose();
     return (System.Drawing.Image)b;
}

In the above method , We got the bitmap image , And then draw images of different sizes ( The image drawn here is based on the specified aspect ratio )
4. Call the above methods , Get the resized image ：

System.Drawing. Image i = resizeImage(b, new Size(100, 100));

Output results ：

Thank you for browsing. , I hope it helped you .