JS method to achieve proportional scaling of images (with C# version code)_javascript skills

The example in this article describes the method of scaling images proportionally in JS. Share it with everyone for your reference, the details are as follows:

js version:

function resizeImage(obj, MaxW, MaxH)
{
 var imageObject = obj;
 var state = imageObject.readyState;
 if(state!='complete') 
 {
  setTimeout("resizeImage("+imageObject+","+MaxW+","+MaxH+")",50);
  return;
 }
 var oldImage = new Image();
 oldImage.src = imageObject.src;
 var dW = oldImage.width; 
 var dH = oldImage.height;
 if(dW>MaxW || dH>MaxH) 
 {
  a = dW/MaxW; b = dH/MaxH;
  if( b>a ) a = b;
  dW = dW/a; dH = dH/a;
 }
 if(dW > 0 && dH > 0) 
 {
  imageObject.width = dW;
  imageObject.height = dH;
 }
}

It’s very simple to use: b09778e546d10c300160044727fe8042 and it’s OK;

Note: Shaking will occur when scaling in equal proportions. The solution is very simple. You set the widht and height of the img attribute first. In this way, it will never exceed this size when loading. Wait for your js After it is running, it will be adjusted to the ratio you specified, and it will never be extended to a very high level.

Also attached is the C# version

/// <summary>
/// 按比例缩放图片
/// </summary>
/// <param name="imgUrl">图片的路径</param>
/// <param name="imgHeight">图片的高度</param>
/// <param name="imgWidth">图片的宽度</param>
/// <returns></returns>
public static string GetImageSize(string imgUrl,int imgHeight,int imgWidth)
{
 string fileName = System.Web.HttpContext.Current.Server.MapPath(imgUrl);
 string strResult = string.Empty;
 if(System.IO.File.Exists(fileName) && imgHeight != 0 && imgWidth != 0)
 {
  decimal desWidth;decimal desHeight;//目标宽高
  System.Drawing.Image objImage = System.Drawing.Image.FromFile(fileName);
  decimal radioAct = (decimal)objImage.Width/(decimal)objImage.Height;//原始图片的宽高比
  decimal radioLoc = (decimal)imgWidth/(decimal)imgHeight;//图片位的宽高比
  if(radioAct > radioLoc)//原始图片比图片位宽
  {  
   decimal dcmZoom = (decimal)imgWidth/(decimal)objImage.Width;
   desHeight = objImage.Height*dcmZoom;
   desWidth = imgWidth;
  }
  else
  {
   decimal dcmZoom = (decimal)imgHeight/(decimal)objImage.Height;
   desWidth = objImage.Width*dcmZoom;
   desHeight = imgHeight;
  }
  objImage.Dispose(); //释放资源
  strResult = "width=\"" + Convert.ToString((int)desWidth) + "\" height=\""
   + Convert.ToString((int)desHeight) + "\" ";
 }
 return strResult;
}

I hope this article will be helpful to everyone in JavaScript programming.