请问如何将大图片缩小显示？
我试过用<asp:Image>和<asp:ImageButton>，指定它的宽度和高度，但只要图片大小超过指定的宽高，都会显示成原始大上，把页面弄得混乱不堪。而且图片太多，不可能全部处理成指定大小，所以上来请教，谢谢!
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应该不会.
<asp:image style="width:100px;height:100px" 不管图片多大都会按指定大小显示
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1 直接使用缩略图
2 将图片转换成一定大小再显示（比例，固定高度和宽度等）
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- C# code
//代码摘自网络,自己定义个类，将相关代码放进去即可使用enum Dimensions { Width, Height } enum AnchorPosition { Top, Center, Bottom, Left, Right }static Image ScaleByPercent(Image imgPhoto, int Percent) { float nPercent = ((float)Percent/100); int sourceWidth = imgPhoto.Width; int sourceHeight = imgPhoto.Height; int sourceX = 0; int sourceY = 0; int destX = 0; int destY = 0; int destWidth = (int)(sourceWidth * nPercent); int destHeight = (int)(sourceHeight * nPercent); Bitmap bmPhoto = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb); bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); Graphics grPhoto = Graphics.FromImage(bmPhoto); grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic; grPhoto.DrawImage(imgPhoto, new Rectangle(destX,destY,destWidth,destHeight), new Rectangle(sourceX,sourceY,sourceWidth,sourceHeight), GraphicsUnit.Pixel); grPhoto.Dispose(); return bmPhoto; } static Image ConstrainProportions(Image imgPhoto, int Size, Dimensions Dimension) { int sourceWidth = imgPhoto.Width; int sourceHeight = imgPhoto.Height; int sourceX = 0; int sourceY = 0; int destX = 0; int destY = 0; float nPercent = 0; switch(Dimension) { case Dimensions.Width: nPercent = ((float)Size/(float)sourceWidth); break; default: nPercent = ((float)Size/(float)sourceHeight); break; } int destWidth = (int)(sourceWidth * nPercent); int destHeight = (int)(sourceHeight * nPercent); Bitmap bmPhoto = new Bitmap(destWidth, destHeight, PixelFormat.Format24bppRgb); bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); Graphics grPhoto = Graphics.FromImage(bmPhoto); grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic; grPhoto.DrawImage(imgPhoto, new Rectangle(destX,destY,destWidth,destHeight), new Rectangle(sourceX,sourceY,sourceWidth,sourceHeight), GraphicsUnit.Pixel); grPhoto.Dispose(); return bmPhoto; } static Image FixedSize(Image imgPhoto, int Width, int Height) { int sourceWidth = imgPhoto.Width; int sourceHeight = imgPhoto.Height; int sourceX = 0; int sourceY = 0; int destX = 0; int destY = 0; float nPercent = 0; float nPercentW = 0; float nPercentH = 0; nPercentW = ((float)Width/(float)sourceWidth); nPercentH = ((float)Height/(float)sourceHeight); //if we have to pad the height pad both the top and the bottom //with the difference between the scaled height and the desired height if(nPercentH < nPercentW) { nPercent = nPercentH; destX = (int)((Width - (sourceWidth * nPercent))/2); } else { nPercent = nPercentW; destY = (int)((Height - (sourceHeight * nPercent))/2); } int destWidth = (int)(sourceWidth * nPercent); int destHeight = (int)(sourceHeight * nPercent); Bitmap bmPhoto = new Bitmap(Width, Height, PixelFormat.Format24bppRgb); bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution); Graphics grPhoto = Graphics.FromImage(bmPhoto); grPhoto.Clear(Color.Red); grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic; grPhoto.DrawImage(imgPhoto, new Rectangle(destX,destY,destWidth,destHeight), new Rectangle(sourceX,sourceY,sourceWidth,sourceHeight), GraphicsUnit.Pixel); grPhoto.Dispose(); return bmPhoto; }