ASP.NET 图片加水印防盗链
首先建一个类：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Drawing;
/// <summary>
///Class1 的摘要说明
/// </summary>
public class Class1:IHttpHandler //调用接口
{
public Class1()
{
//
//TODO: 在此处添加构造函数逻辑
//
}
public bool IsReusable
{
get { return true; }
}
public void ProcessRequest(HttpContext context)
{
HttpRequest req = context.Request;
if (req.UrlReferrer != null && req.UrlReferrer.Host.Length > 0) //反盗链代码判断
{
System.Drawing.Image img = System.Drawing.Image.FromFile(context.Request.PhysicalPath);
System.Drawing.Graphics g = Graphics.FromImage(img);
g.DrawString("三国演义", new Font("宋体", 20, FontStyle.Bold), Brushes.White, 10, 10);
img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
context.Response.Flush();
context.Response.End();
}
else
{
context.Response.Write("您不能盗链本站图片");
}
}
}
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Drawing;
/// <summary>
///Class1 的摘要说明
/// </summary>
public class Class1:IHttpHandler //调用接口
{
public Class1()
{
//
//TODO: 在此处添加构造函数逻辑
//
}
public bool IsReusable
{
get { return true; }
}
public void ProcessRequest(HttpContext context)
{
HttpRequest req = context.Request;
if (req.UrlReferrer != null && req.UrlReferrer.Host.Length > 0) //反盗链代码判断
{
System.Drawing.Image img = System.Drawing.Image.FromFile(context.Request.PhysicalPath);
System.Drawing.Graphics g = Graphics.FromImage(img);
g.DrawString("三国演义", new Font("宋体", 20, FontStyle.Bold), Brushes.White, 10, 10);
img.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
context.Response.Flush();
context.Response.End();
}
else
{
context.Response.Write("您不能盗链本站图片");
}
}
}
<httpHandlers>
<add verb="*" path="images/*.jpg" type="Class1,App_Code"/>
</httpHandlers>
<add verb="*" path="images/*.jpg" type="Class1,App_Code"/>
</httpHandlers>
参考：
1.修改web.config
<system.web> <httpHandlers> <remove verb="*" path="*.asmx"/> <!--解决图片防盗链问题--> <add verb="*" path="*.jpg" type="MyHttpHandler.Watermark"/> <add verb="*" path="*.gif" type="MyHttpHandler.Watermark"/> <add verb="*" path="*.png" type="MyHttpHandler.Watermark"/> </httpHandlers></system.web> |
2.添加一个一般执行文件Watermark.ashx，代码如下：
using System;using System.Data;using System.Web;using System.Collections;using System.Web.Services;using System.Web.Services.Protocols;using System.Drawing.Imaging;using System.Drawing;using System.IO;namespace MyHttpHandler{ /// <summary> /// Summary description for $codebehindclassname$ /// </summary> [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] public class Watermark : IHttpHandler { public bool IsReusable { get { return false; } } public void ProcessRequest(HttpContext context) { //设置客户端缓冲时间过期时间为0，即立即过期 //context.Response.Expires = 0; //清空服务器端为此会话开启的输出缓存 //context.Response.Clear(); //设置输出文件类型 context.Response.ContentType = "image/jpg"; //将请求文件写入到输出缓存中 #region 获取XML配置信息 DataSet dsConfing = new DataSet(); string watermarkConfigPath = context.Server.MapPath("~/Config/WaterMarkConfig.xml"); if (System.IO.File.Exists(watermarkConfigPath)) dsConfing.ReadXml(watermarkConfigPath); else { //添加默认的水印配置 } DataRow drConfing = dsConfing.Tables[0].Rows[0]; #endregion string currentHost = drConfing["allowhost"].ToString(); //判断是否是本地网站引用图片，如果是则返回正确的图片 if (context.Request.Url.Authority.Equals(currentHost, StringComparison.InvariantCultureIgnoreCase)) { string localPath = context.Request.Url.LocalPath; localPath = localPath.Remove(localPath.LastIndexOf('/')).ToLower();// "/images/userphoto" if (drConfing["isflag"].Equals("true") && drConfing["files"].ToString().ToLower().IndexOf(localPath) > 0) { #region 水印代码 string sImgStartPhysicalPath = context.Request.PhysicalPath; System.Drawing.Image imgStart = System.Drawing.Image.FromFile(sImgStartPhysicalPath); //备份原图片 //int indexOf = sImgStartPhysicalPath.LastIndexOf("."); //string bakPath = sImgStartPhysicalPath.Remove(indexOf) + "_bak" + sImgStartPhysicalPath.Substring(indexOf); //imgStart.Save(bakPath); Graphics gh = System.Drawing.Graphics.FromImage(imgStart); if (drConfing["type"].Equals("img")) { System.Drawing.Image imgWatermark = System.Drawing.Image.FromFile(context.Server.MapPath(drConfing["img-path"].ToString())); Rectangle rg = SetImgPosition(drConfing["position"].ToString(), imgStart.Width, imgStart.Height, imgWatermark.Width, imgWatermark.Height); gh.DrawImage(imgWatermark, rg, 0, 0, imgWatermark.Width, imgWatermark.Height, GraphicsUnit.Pixel); gh.Save(); gh.Dispose(); imgWatermark.Dispose(); } else if (drConfing["type"].Equals("font")) { //文字水印 string content = drConfing["font-content"].ToString(); float Size = (float)Convert.ToDouble(drConfing["font-size"].ToString()); FontStyle fontStyle = (FontStyle)int.Parse(drConfing["font-style"].ToString()); System.Drawing.Font f = new System.Drawing.Font("Arial", Size, fontStyle); Color G_Color = Color.FromName(drConfing["font-color"].ToString()); System.Drawing.Brush b = new System.Drawing.SolidBrush(G_Color); SizeF sizeF = gh.MeasureString(content, f); gh.DrawString(content, f, b, SetFontPosition(drConfing["position"].ToString(), imgStart.Width, imgStart.Height, (int)sizeF.Width, (int)sizeF.Height)); gh.Save(); gh.Dispose(); } //将请求文件写入到输出缓存中 imgStart.Save(context.Response.OutputStream, ImageFormat.Jpeg); imgStart.Dispose(); #endregion } else { #region 输出原图 //将请求文件写入到输出缓存中 context.Response.WriteFile(context.Request.Url.AbsolutePath); #endregion } } //如果不是本地引用，则是盗链本站图片 else { //将请求文件写入到输出缓存中 context.Response.WriteFile(context.Request.PhysicalApplicationPath + drConfing["errimgpath"].ToString()); } //将输出缓存中的信息传送到客户端 context.Response.End(); } /// <summary> /// 图片绘画水印的位置 /// </summary> /// <param name="positionConfig">位置类型</param> /// <param name="width">原图片宽</param> /// <param name="height"></param> /// <param name="watermarkWidth">水印图宽</param> /// <param name="watermarkHeight"></param> /// <returns></returns> private Rectangle SetImgPosition(string positionConfig,int width,int height,int watermarkWidth,int watermarkHeight) { int xpos = 0; int ypos = 0; int margin = 10; int width_margin = width - margin; int height_margin = height - margin; double proportion = 1d;//水印图片缩放比例 //int if ((width_margin > watermarkWidth * proportion) && (height_margin > watermarkHeight * proportion)) { } else if ((width_margin > watermarkWidth * proportion) && (height_margin < watermarkHeight * proportion)) { proportion = Convert.ToDouble( height_margin) / Convert.ToDouble( watermarkHeight); } else if ((width_margin < watermarkWidth * proportion) && (height_margin > watermarkHeight * proportion)) { proportion = Convert.ToDouble(width_margin) / Convert.ToDouble(watermarkWidth); } else { double proportionW = Convert.ToDouble(width_margin) / Convert.ToDouble(watermarkWidth); double proportionH = Convert.ToDouble(height_margin) / Convert.ToDouble(watermarkHeight); proportion = proportionW >= proportionH ? proportionH : proportionW; } watermarkWidth = Convert.ToInt32(watermarkWidth * proportion); watermarkHeight = Convert.ToInt32(watermarkHeight * proportion); switch (positionConfig) { case "top-left": xpos = margin; ypos = margin; break; case "top-right": xpos = width_margin - watermarkWidth; ypos = margin; break; case "bottom-left": xpos = margin; ypos = height_margin - watermarkHeight; break; case "bottom-right": xpos = width_margin - watermarkWidth ; ypos = height_margin - watermarkHeight ; break; default: xpos = width_margin - watermarkWidth ; ypos = height_margin - watermarkHeight; break; } return new Rectangle(xpos,ypos,watermarkWidth,watermarkHeight); } /// <summary> /// 图片绘画文字位置 /// </summary> /// <param name="positionConfig">位置类型</param> /// <param name="width">原图片宽</param> /// <param name="height"></param> /// <param name="fontWidth">文字长度</param> /// <param name="fontHeight"></param> /// <returns></returns> private Point SetFontPosition(string positionConfig, int width, int height, int fontWidth, int fontHeight) { int xpos = 0; int ypos = 0; int margin = 10; int width_margin = width - margin; int height_margin = height - margin; double proportion = 1d;//水印图片缩放比例 //int if ((width_margin > fontWidth * proportion) && (height_margin > fontHeight * proportion)) { } else if ((width_margin > fontWidth * proportion) && (height_margin < fontHeight * proportion)) { proportion = Convert.ToDouble(height_margin) / Convert.ToDouble(fontHeight); } else if ((width_margin < fontWidth * proportion) && (height_margin > fontHeight * proportion)) { proportion = Convert.ToDouble(width_margin) / Convert.ToDouble(fontWidth); } else { double proportionH = Convert.ToDouble(height_margin) / Convert.ToDouble(fontHeight); double proportionW = Convert.ToDouble(width_margin) / Convert.ToDouble(fontWidth); proportion = proportionW >= proportionH ? proportionH : proportionW; } fontWidth = Convert.ToInt32(fontWidth * proportion); fontHeight = Convert.ToInt32(fontHeight * proportion); switch (positionConfig) { case "top-left": xpos = margin; ypos = margin; break; case "top-right": xpos = width_margin - fontWidth; ypos = margin; break; case "bottom-left": xpos = margin; ypos = height_margin - fontHeight; break; case "bottom-right": xpos = width_margin - fontWidth; ypos = height_margin - fontHeight; break; default: xpos = width_margin - fontWidth; ypos = height_margin - fontHeight; break; } return new Point(xpos, ypos); } }} |
3.配置文件的WaterMarkConfig.xml，内容如下：
<?xml version="1.0" encoding="utf-8" ?><watermark> <allowhost>localhost:6219</allowhost><!--允许访问的域名--> <isflag>true</isflag><!-- true、false--> <type>font</type><!-- img、font--> <files>/config|/upfiles/ab</files><!--需要加水印的文件夹--> <position>bottom-right</position><!-- top-left、top-right、bottom-left、bottom-right--> <img-path>~/UpFiles/Watermark.png</img-path><!-- 水印位置 --> <font-style>1</font-style><!--普通文本 0, 加粗文本 1, 倾斜文本 2, 带下划线的文本 4, 中间有直线通过的文本 8--> <font-size>60</font-size> <font-color>red</font-color> <font-content>￥：8000元</font-content> <errimgpath>images/error.jpg</errimgpath><!-- 盗图片的请求返回的跟目录下的某图片 --></watermark> |
