【加水印】ASP.NET 图片加水印防盗链实现代码-防盗链

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ASP.NET 图片加水印防盗链实现代码

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>
[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();
}
/// <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);
}
}
}

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