ASP.NET 生成缩略图
以下代码根据生成图片的宽、高，生成四种模式的图片缩略图
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.IO;
public partial class ImgOperator_ImageCut : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
MakeThumbImage("~/images/DSC01010.JPG", "~/images/cut5.jpg", 800, 450, "BGCUT");
}
private void MakeThumbImage(string initPath, string outPath, int width, int height, string mode)
{
System.Drawing.Image image=System.Drawing.Image.FromFile(Server.MapPath(initPath));
int tw = width;
int th = height;
//生成的图片大小
int sw = image.Width;
int sh = image.Height;
int x = 0;
int y = 0;
switch (mode)
{
case "HW":
break;
case "W":
th = width * image.Height / image.Width;
break;
case "H":
tw = height * image.Width / image.Height;
break;
case "CUT":
if ((double)sw / (double)sh < (double)width / (double)height)
{
sw = image.Width;
sh = image.Width * th / tw;
x = 0;
y = (image.Height - sh) / 2;
}
else
{
sh = image.Height;
sw = image.Height * tw / th;
x = (image.Width - sw) / 2;
y = 0;
}
break;
case "BGCUT":
if ((double)width / (double)height < (double)image.Width / (double)image.Height)
{
sw = image.Width;
sh = image.Width * th / tw;
x = 0;
y = (image.Height - sh) / 2;
}
else
{
sh = image.Height;
sw = image.Height * tw / th;
x = (image.Width - sw) / 2;
y = 0;
}
break;
default: break;
}
System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(tw, th);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bmp);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.Clear(System.Drawing.Color.WhiteSmoke);
g.DrawImage(image,new System.Drawing.Rectangle(0,0,tw,th),new System.Drawing.Rectangle(x,y,sw,sh),System.Drawing.GraphicsUnit.Pixel);
try
{
string oPath = Server.MapPath(outPath);
bmp.Save(oPath, System.Drawing.Imaging.ImageFormat.Jpeg);
FileStream fs = new FileStream(oPath, FileMode.Open, FileAccess.Read);
byte[] imgData = new byte[(int)fs.Length];
fs.Read(imgData, 0, (int)fs.Length);
Response.BinaryWrite(imgData);
Response.ContentType = "image/pjpeg";
Response.End();
//bmp.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
finally
{
image.Dispose();
bmp.Dispose();
g.Dispose();
}
}
}