/// <summary>
/// 保存缩略图到磁盘(可指定宽高，可指定缩放模式)
/// </summary>
/// <param name="srcPath"></param>
/// <param name="destPath"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="mode"></param>
public static void SaveThumbnail(String srcPath, String destPath, int width, int height)
{
using (Image srcImg = Image.FromFile(srcPath))
{
ThumbSize t = getCutSize(width, height, srcImg);
using (Bitmap newImg = new Bitmap(t.New.Width, t.New.Height))
{
using (Graphics g = Graphics.FromImage(newImg))
{
g.InterpolationMode = InterpolationMode.High;
g.SmoothingMode = SmoothingMode.HighQuality;
g.Clear(Color.Transparent);
g.DrawImage(srcImg, t.getNewRect(), t.getRect(), GraphicsUnit.Pixel);
try
{
newImg.Save(destPath, ImageFormat.Jpeg);
}
catch (Exception e)
{
throw e;
}
}
}
}
}
private static ThumbSize getCutSize(int width, int height, Image src)
{
ThumbSize t = new ThumbSize();
if ((double)src.Width / (double)src.Height > (double)width / (double)height)
{
int newWidth = src.Height * width / height;
t.Src = new Size(newWidth, src.Height);
t.New = new Size(width, height);
t.Point = new Point((src.Width - newWidth) / 2, 0);
}
else
{
int newHeight = src.Width * height / width;
t.Src = new Size(src.Width, newHeight);
t.New = new Size(width, height);
t.Point = new Point(0, (src.Height - newHeight) / 2);
}
return(t);
}