任何人都知道着名的PHP类“timthumb”的ASP.Net版本？只需要一个可以在同一行“timthumb”中工作的脚本，并为任何尺寸的图像生成高质量的基于方形或比率的缩略图。
以下是php类的链接：http://www.darrenhoyt.com/2008/04/02/timthumb-php-script-released/
答案 0 :(得分：5)
我为你编写了这个:) :)我通过尝试http://www.binarymoon.co.uk/demo/timthumb-basic/中的所有案例并将其与我的代码并排进行比较来测试它。据我所知，它基本相同。据说它不支持'zc'标志。
我把它写成通用处理程序（ashx文件），以便它运行得更快。支持成像缓存，但我对其进行了评论，因为它使测试修复非常困难。随意取消注释以提高性能（在开始时一个块，在将内容写入内存流时一个接近结束）。
--- ---代码
<%@ WebHandler Language="VB" Class="Thumb" %>
Imports System
Imports System.Web
Imports System.Drawing
Imports System.IO
Public Class Thumb : Implements IHttpHandler
Private Shared _DefaultWidth As Integer = 100
Private Shared _DefaultHeight As Integer = 100
Private Shared _DefaultQuality As Integer = 90
Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
''check the cache for the image first
'Dim cacheObj As Object = context.Cache("Thumb-" + context.Request.Url.ToString().ToLower())
'If cacheObj IsNot Nothing Then
' Dim msCache As MemoryStream = DirectCast(cacheObj, MemoryStream)
' WriteImage(msCache, context)
' Exit Sub
'End If
'process request (since it wasn't in the cache)
Dim imgPath As String = context.Request.QueryString("src")
If String.IsNullOrEmpty(imgPath) Then
context.Response.End()
End If
'get image path on server
Dim serverPath As String = context.Server.MapPath(imgPath)
If Not File.Exists(serverPath) Then
context.Response.End()
End If
'load image from file path
Dim img As Image = Bitmap.FromFile(serverPath)
Dim origRatio As Double = (Math.Min(img.Width, img.Height) / Math.Max(img.Width, img.Height))
'---Calculate thumbnail sizes---
Dim destWidth As Integer = 0
Dim destHeight As Integer = 0
Dim destRatio As Double = 0
Dim qW As String = context.Request.QueryString("w")
Dim qH As String = context.Request.QueryString("h")
If Not String.IsNullOrEmpty(qW) Then
Int32.TryParse(qW, destWidth)
If destWidth < 0 Then
destWidth = 0
End If
End If
If Not String.IsNullOrEmpty(qH) Then
Int32.TryParse(qH, destHeight)
If destHeight < 0 Then
destHeight = 0
End If
End If
'if both width and height are 0 then use defaults (100x100)
If destWidth = 0 And destHeight = 0 Then
destWidth = _DefaultWidth
destHeight = _DefaultHeight
'else, if the width is specified, calculate an appropriate height
ElseIf destWidth > 0 And destHeight > 0 Then
'do nothing, we have both sizes already
ElseIf destWidth > 0 Then
destHeight = Math.Floor(img.Height * (destWidth / img.Width))
ElseIf destHeight > 0 Then
destWidth = Math.Floor(img.Width * (destHeight / img.Height))
End If
destRatio = (Math.Min(destWidth, destHeight) / Math.Max(destWidth, destHeight))
'calculate source image sizes (rectangle) to get pixel data from
Dim sourceWidth As Integer = img.Width
Dim sourceHeight As Integer = img.Height
Dim sourceX As Integer = 0
Dim sourceY As Integer = 0
Dim cmpx As Integer = img.Width / destWidth
Dim cmpy As Integer = img.Height / destHeight
'selection is based on the smallest dimension
If cmpx > cmpy Then
sourceWidth = img.Width / cmpx * cmpy
sourceX = ((img.Width - (img.Width / cmpx * cmpy)) / 2)
ElseIf cmpy > cmpx Then
sourceHeight = img.Height / cmpy * cmpx
sourceY = ((img.Height - (img.Height / cmpy * cmpx)) / 2)
End If
'---create the new thumbnail image---
Dim bmpThumb As New Bitmap(destWidth, destHeight)
Dim g = Graphics.FromImage(bmpThumb)
g.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBicubic
g.CompositingQuality = Drawing2D.CompositingQuality.HighQuality
g.SmoothingMode = Drawing2D.SmoothingMode.AntiAlias
g.DrawImage(img, _
New Rectangle(0, 0, destWidth, destHeight), _
New Rectangle(sourceX, sourceY, sourceWidth, sourceHeight), GraphicsUnit.Pixel)
'-----write out Thumbnail to the output stream------
'get jpeg image coded info so we can use it when saving
Dim ici As Imaging.ImageCodecInfo = Imaging.ImageCodecInfo.GetImageEncoders().Where(Function(c) c.MimeType = "image/jpeg").First()
'save image to memory stream
Dim ms As New MemoryStream()
bmpThumb.Save(ms, ici, BuildQualityParams(context))
''save image to cache for future use
'context.Cache("Thumb-" + context.Request.Url.ToString().ToLower()) = ms
'write the image out
WriteImage(ms, context)
End Sub
Private Sub WriteImage(ByVal ms As MemoryStream, ByVal context As HttpContext)
'clear the response stream
context.Response.Clear()
'set output content type to jpeg
context.Response.ContentType = "image/jpeg"
'write memory stream out
ms.WriteTo(context.Response.OutputStream)
'flush the stream and end the response
context.Response.Flush()
context.Response.End()
End Sub
'for adjusting quality setting if needed, otherwise 90 will be used
Private Function BuildQualityParams(ByVal context As HttpContext) As Imaging.EncoderParameters
Dim epParams As New Imaging.EncoderParameters(1)
Dim q As Integer = _DefaultQuality
Dim strQ As String = context.Request.QueryString("q")
If Not String.IsNullOrEmpty(strQ) Then
Int32.TryParse(strQ, q)
End If
epParams.Param(0) = New Imaging.EncoderParameter(Imaging.Encoder.Quality, q)
Return epParams
End Function
Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
Get
Return False
End Get
End Property
End Class
---测试案例---
<img alt="" src="Thumb.ashx?src=~/images/castle1.jpg" />
<br />
<img alt="" src="Thumb.ashx?src=~/images/castle1.jpg&q=100" />
<br />
<img alt="" src="Thumb.ashx?src=~/images/castle1.jpg&q=10" />
<br />
<img alt="" src="Thumb.ashx?src=~/images/castle1.jpg&w=200" />
<br />
<img alt="" src="Thumb.ashx?src=~/images/castle1.jpg&h=150" />
<br />
<img alt="" src="Thumb.ashx?src=~/images/castle1.jpg&h=180&w=120" />
<br />
<img alt="" src="Thumb.ashx?src=~/images/castle1.jpg&h=80&w=210" />
<br />
答案 1 :(得分：4)
@ Peter感谢您上面的代码，它在我的ashx文件中完美运行。我是一个asp.net c＃开发人员，所以我已经将你的vb代码转换为c＃并修复了我遇到的一些问题。
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.Diagnostics;
using System.Web;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
namespace myProject.Handlers
{
public class Thumb : IHttpHandler
{
private static int _DefaultWidth = 100;
private static int _DefaultHeight = 100;
private static int _DefaultQuality = 90;
public void ProcessRequest(HttpContext context)
{
string imgPath = context.Request.QueryString["src"];
if (string.IsNullOrEmpty(imgPath))
{
context.Response.End();
}
string serverPath = context.Server.MapPath(imgPath);
if (!File.Exists(serverPath))
{
context.Response.End();
}
Image img = Bitmap.FromFile(serverPath);
double origRatio = (Math.Min(img.Width, img.Height) / Math.Max(img.Width, img.Height));
int destWidth = 0;
int destHeight = 0;
double destRatio = 0;
double dHeight = 0;
double dWidth = 0;
string qW = context.Request.QueryString["w"];
string qH = context.Request.QueryString["h"];
if (!string.IsNullOrEmpty(qW))
{
Int32.TryParse(qW, out destWidth);
if (destWidth < 0)
{
destWidth = 0;
}
}
if (!string.IsNullOrEmpty(qH))
{
Int32.TryParse(qH, out destHeight);
if (destHeight < 0)
{
destHeight = 0;
}
}
if (destWidth == 0 & destHeight == 0)
{
destWidth = _DefaultWidth;
destHeight = _DefaultHeight;
}
else if (destWidth > 0 & destHeight > 0)
{
//do nothing, we have both sizes already
}
else if (destWidth > 0)
{
dHeight = double.Parse(destWidth.ToString()) / double.Parse(img.Width.ToString());
destHeight = int.Parse(Math.Floor(img.Height * dHeight).ToString());
}
else if (destHeight > 0)
{
dWidth = double.Parse(destHeight.ToString()) / double.Parse(img.Height.ToString());
destWidth = int.Parse(Math.Floor(img.Width * dWidth).ToString());
}
destRatio = (Math.Min(destWidth, destHeight) / Math.Max(destWidth, destHeight));
int sourceWidth = img.Width;
int sourceHeight = img.Height;
int sourceX = 0;
int sourceY = 0;
int cmpx = img.Width / destWidth;
int cmpy = img.Height / destHeight;
if (cmpx > cmpy)
{
sourceWidth = img.Width / cmpx * cmpy;
sourceX = ((img.Width - (img.Width / cmpx * cmpy)) / 2);
}
else if (cmpy > cmpx)
{
sourceHeight = img.Height / cmpy * cmpx;
sourceY = ((img.Height - (img.Height / cmpy * cmpx)) / 2);
}
Bitmap bmpThumb = new Bitmap(destWidth, destHeight);
Graphics g = Graphics.FromImage(bmpThumb);
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.CompositingQuality = CompositingQuality.HighQuality;
g.SmoothingMode = SmoothingMode.AntiAlias;
g.DrawImage(img, new Rectangle(0, 0, destWidth, destHeight), new Rectangle(sourceX, sourceY, sourceWidth, sourceHeight), GraphicsUnit.Pixel);
ImageCodecInfo ici = ImageCodecInfo.GetImageEncoders().Where(c => c.MimeType == "image/jpeg").First();
MemoryStream ms = new MemoryStream();
bmpThumb.Save(ms, ici, BuildQualityParams(context));
WriteImage(ms, context);
}
private void WriteImage(MemoryStream ms, HttpContext context)
{
context.Response.Clear();
context.Response.ContentType = "image/jpeg";
ms.WriteTo(context.Response.OutputStream);
context.Response.Flush();
context.Response.End();
}
private EncoderParameters BuildQualityParams(HttpContext context)
{
EncoderParameters epParams = new EncoderParameters(1);
int q = _DefaultQuality;
string strQ = context.Request.QueryString["q"];
if (!string.IsNullOrEmpty(strQ))
{
Int32.TryParse(strQ, out q);
}
epParams.Param[0] = new EncoderParameter(Encoder.Quality, q);
return epParams;
}
public bool IsReusable
{
get
{
return false;
}
}
}
}
答案 2 :(得分：1)
看起来你想做这样的事情： http://www.4guysfromrolla.com/articles/012203-1.aspx
最糟糕的是，timthumb是开源的，因此您可以在.NET中创建它并向世界开源！ （当然，正确归属于原文）
答案 3 :(得分：1)
http://imageresizing.net库可以完成TimThumb脚本所做的所有事情。它非常易于安装和完全支持。
TimThumb：image.jpg？w = 100＆amp; h = 100＆amp; q = 90
ImageResizing.Net：image.jpg？width = 100＆amp; height = 100＆amp; quality = 100
如果你需要模仿timthumb的确切语法，请告诉我，我可以给你几行代码来使它工作。