不多說了，直接看代碼：
/// <summary>
/// 縮略圖
/// </summary>
/// <param name="imgurl">大圖片路徑</param>
/// <param name="thumbnailPath">小圖片路徑</param>
public static void MakeThumbnail(string imgurl, string thumbnailPath)
{
int width = 100;//縮略圖照片寬度
int height = 62;//縮略圖照片高度
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(imgurl);
int towidth = 0;
int toheight = 0;
if (originalImage.Width > width && originalImage.Height < height)
{
towidth = width;
toheight = originalImage.Height;
}
if (originalImage.Width < width && originalImage.Height > height)
{
towidth = originalImage.Width;
toheight = height;
}
if (originalImage.Width > width && originalImage.Height > height)
{
towidth = width;
toheight = height;
}
if (originalImage.Width < width && originalImage.Height < height)
{
towidth = originalImage.Width;
toheight = originalImage.Height;
}
int x = 0;//左上角的x座標
int y = 0;//左上角的y座標
//新建一個bmp圖片
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
//新建一個畫板
Graphics g = System.Drawing.Graphics.FromImage(bitmap);
//設置高質量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//設置高質量,低速度呈現平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空畫布並以透明背景色填充
g.Clear(Color.Transparent);
//在指定位置並且按指定大小繪製原圖片的指定部分
g.DrawImage(originalImage, x, y, towidth, toheight);
try
{
//以jpg格式保存縮略圖
bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch (System.Exception e)
{
throw e;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
}