ASP.NET 图片加水印防盗链
ASP.NET 图片加水印防盗链
在web.config中注册接口：
url: http://greatverve.cnblogs.com/archive/2011/12/20/asp-net-hotlinking.html
参考：
首先建一个类：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Drawing;
///
/// Class1 的摘要说明
///
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;
///
/// Class1 的摘要说明
///
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
?
|
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 description for $codebehindclassname$
///
[WebService(Namespace =
"http://tempuri.org/"
)]
[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();
}
///
/// 图片绘画水印的位置
///
/// 位置类型
/// 原图片宽
///
/// 水印图宽
///
///
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);
}
///
/// 图片绘画文字位置
///
/// 位置类型
/// 原图片宽
///
/// 文字长度
///
///
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：
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true
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posted @
2012-01-29 19:39 Chaoa 阅读(
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