前台：
<asp:FileUpload ID="FileUpload1" runat="server" />
<asp:Button ID="Button1" runat="server" Text="上传" onclick="Button1_Click" />
后台：
using System.Drawing;
using System.IO;
/// <summary>
/// 生成缩略图的方法
/// </summary>
/// <param name="Path">原始图片路径</param>
/// <param name="StPath">生成图片存放的路径</param>
/// <param name="width">生成图片的宽度</param>
/// <param name="height">生成图片的高度</param>
/// <param name="mode">生成的模式（ "HW":指定高宽缩放；"W"://指定宽度，计算缩略图；"H":指定高度，计算缩略图；"CUT":）</param>
/// <returns></returns>
public static string MakeThumbImage(string Path, string StPath, int width, int height, string mode)
{
string messages = string.Empty;
System.Drawing.Image image = System.Drawing.Image.FromFile(Path);
int tw = width;
int th = height;
//原始图片的宽度和高度
int sw = image.Width;
int sh = image.Height;
int x = 0, y = 0;
switch (mode)
{
case "HW"://指定高宽缩放
break;
case "W"://按比例缩放，指定宽度，计算缩略图的高度
th = image.Height * width / image.Width;
break;
case "H"://按比例缩放，指定高度，计算缩略图的高度
tw = image.Width * height / image.Height;
break;
case "CUT":
if ((double)tw / (double)th < (double)width / (double)height)
{
sw = image.Width;
sh = image.Width * height / tw;
x = 0;
y = (image.Height - sh) / 2;
}
else
{
sh = image.Height;
sw = image.Height * width / th;
y = 0;
x = (image.Width - sw) / 2;
}
break;
default: break;
}
System.Drawing.Image bitmap = new System.Drawing.Bitmap(tw, th);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.Clear(System.Drawing.Color.Transparent);
g.DrawImage(image,
new System.Drawing.Rectangle(x, y, tw, th),
new System.Drawing.Rectangle(x, y, sw, sh),
System.Drawing.GraphicsUnit.Pixel);
try
{
bitmap.Save(StPath, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch (Exception ex)
{
messages = ex.Message;
}
finally
{
image.Dispose();
bitmap.Dispose();
g.Dispose();
if (messages == string.Empty)
{
messages = "成功生成！";
}
}
return messages;
}
- 本文标题： 生成缩略图片 ASP.NET
- 文章分类：【.NET/Web】
- 非特殊说明，本文版权归【胡同里的砖头】个人博客 所有，转载请注明出处.