关于asp。net GDI+图片的等比例缩放
我需要做一个功能,就是在后台上传一张图片,用gdi+把他等比例缩放成一张大图和一张小图保存到数据库 方便调用可是我在网上找的代码都会报同一个错误 gdi+ 中发生一般性错误 也不知道到时是什么错误 网上找的代码 看得也不太懂,求高人指点!代码执行到最后一行出错/// <SUMMARY>
/// 图片缩放
/// </SUMMARY>
/// <PARAM name="sourceFile">图片源路径</PARAM>
/// <PARAM name="destFile">缩放后图片输出路径</PARAM>
/// <PARAM name="destHeight">缩放后图片高度</PARAM>
/// <PARAM name="destWidth">缩放后图片宽度</PARAM>
/// <RETURNS></RETURNS>
public static bool GetThumbnail(string sourceFile, string destFile, int destHeight, int destWidth)
{
System.Drawing.Image imgSource = System.Drawing.Image.FromFile(sourceFile);
System.Drawing.Imaging.ImageFormat thisFormat = imgSource.RawFormat;
int sW = 0, sH = 0;
// 按比例缩放
int sWidth = imgSource.Width;
int sHeight = imgSource.Height;
if (sHeight > destHeight || sWidth > destWidth)
{
if ((sWidth * destHeight) > (sHeight * destWidth))
{
sW = destWidth;
sH = (destWidth * sHeight) / sWidth;
}
else
{
sH = destHeight;
sW = (sWidth * destHeight) / sHeight;
}
}
else
{
sW = sWidth;
sH = sHeight;
}
Bitmap outBmp = new Bitmap(destWidth, destHeight);
Graphics g = Graphics.FromImage(outBmp);
g.Clear(Color.WhiteSmoke);
// 设置画布的描绘质量
g.CompositingQuality = CompositingQuality.HighQuality;
g.SmoothingMode = SmoothingMode.HighQuality;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(imgSource, new Rectangle((destWidth - sW) / 2, (destHeight - sH) / 2, sW, sH), 0, 0, imgSource.Width, imgSource.Height, GraphicsUnit.Pixel);
g.Dispose();
// 以下代码为保存图片时,设置压缩质量
EncoderParameters encoderParams = new EncoderParameters();
long[] quality = new long[1];
quality[0] = 100;
EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
encoderParams.Param[0] = encoderParam;
try
{
//获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。
ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo jpegICI = null;
for (int x = 0; x < arrayICI.Length; x++)
{
if (arrayICI[x].FormatDescription.Equals("JPEG"))
{
jpegICI = arrayICI[x];//设置JPEG编码
break;
}
}
if (jpegICI != null)
{
outBmp.Save(destFile, jpegICI, encoderParams);
}
else
{
outBmp.Save(destFile, thisFormat);
}
return true;
}
catch
{
return false;
}
finally
{
imgSource.Dispose();
outBmp.Dispose();
}
}
补充:.NET技术 , ASP.NET