日期:2014-05-17 浏览次数:21076 次
public void MakeThumbnail(string imgPath_old, int width, int height)
{
System.Drawing.Image img = System.Drawing.Image.FromStream(new System.IO.MemoryStream(System.IO.File.ReadAllBytes(imgPath_old)));
int towidth = width; int toheight = height;
int x = 0; int y = 0; int ow = img.Width;
int oh = img.Height;
// 按值较大的进行等比缩放(不变形)
if ((double)img.Width / (double)towidth < (double)img.Height / (double)toheight)
{
toheight = height;
towidth = img.Width * height / img.Height;
}
else
{
towidth = width;
toheight = img.Height * width / img.Width;
}
//新建一个bmp图片
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
//新建一个画板
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
//设置高质量插值法
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
//设置高质量,低速度呈现平滑程度
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//清空画布并以透明背景色填充
g.Clear(System.Drawing.Color.Transparent);
//在指定位置并且按指定大小绘制原图片的指定部分
g.DrawImage(img, new System.Drawing.Rectangle(0, 0, towidth, toheight),
new System.Drawing.Rectangle(x, y, ow, oh),