用ASP.NET实现简单的文字水印

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代码如下:

<%@ Import Namespace="System" %>
<%@ Import Namespace="System.IO" %>
<%@ Import Namespace="System.Drawing" %>

<%@ Page language="vb" %>

<script runat="server">
Dim FilePath As String = Server.MapPath("FengEr.jpg")

Sub Page_Load(Sender As Object, E As EventArgs)
Dim image As System.Drawing.Image = System.Drawing.Image.FromFile( FilePath )
Dim g As Graphics = Graphics.FromImage(image)
g.DrawImage(image, 0, 0, image.Width, image.Height)
Dim f As Font = new Font("华文行楷", 30)
Dim b As Brush = new SolidBrush(Color.Green)
Dim s As String = Request.QueryString("Str")
g.DrawString(s, f, b, 20, 290)
image.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg)
g.Dispose()
image.Dispose()
End Sub
</script>

只要把这个代码存成一个ASPx文件，比如Test.ASPx。然后放到wwwroot里面（假设你的虚拟目录是默认的）。再做一个Test.jpg的图片，就可以在(20, 290)这个位置打印出“华文行楷”这种字体的文字了。调用方法很简单：

http://localhost/Test.ASPx?Str=Dicky's Blog！

对于打印的位置和字体还有图片文件都是可以自己设定的。另外，如果出现了以英文作为参数就可以正常显示，而对于中文就无法显示的情况，是因为ASP.NET的web.config设置不正确造成了，需要进行如下设置：

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<system.web>
<globalization requestEncoding="gb2312" responseEncoding="gb2312" culture="zh-CN" fileEncoding="gb2312"/>
</system.web>
</configuration>

这样，就可以正常显示了。

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