JS实现按比例缩放图片的方法(附C#版代码)

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; }}

/// <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;}