asp.net 使用Response.Filter 过滤非法词汇_.net

asp.net 使用Response.Filter 过滤非法词汇

另一种解决方案是在输出时过滤掉非常词汇，优点是只要写一次就好了，可以过滤整站的非法词汇，缺点是，非法词汇仍然存入到了数据库中，呵呵，大家可以有针对性的选择，本例用的是后者，起因在于当初没有做此功能，后来需要添加，这时又不想改原来代码，所以就想了这个办法，主要是采用了httpresponse.filter属性来处理。具体代码如下：

首先自定义一个类，来作为非法词汇的过滤器

复制代码代码如下:

 
public class responsefilter:stream 
{ 
#region properties 
stream responsestream; 
long position; 
stringbuilder html = new stringbuilder(); 
#endregion 
#region constructor 
public responsefilter(stream inputstream) 
{ 
responsestream = inputstream; 
} 
#endregion 
#region implemented abstract members 
public override bool canread 
{ 
get { return true; } 
} 
public override bool canseek 
{ 
get { return true; } 
} 
public override bool canwrite 
{ 
get { return true; } 
} 
public override void close() 
{ 
responsestream.close(); 
} 
public override void flush() 
{ 
responsestream.flush(); 
} 
public override long length 
{ 
get { return 0; } 
} 
public override long position 
{ 
get { return position; } 
set { position = value; } 
} 
public override long seek(long offset, system.io.seekorigin direction) 
{ 
return responsestream.seek(offset, direction); 
} 
public override void setlength(long length) 
{ 
responsestream.setlength(length); 
} 
public override int read(byte[] buffer, int offset, int count) 
{ 
return responsestream.read(buffer, offset, count); 
} 
#endregion 
#region write method 
public override void write(byte[] buffer, int offset, int count) 
{ 
string sbuffer = system.text.utf8encoding.utf8.getstring(buffer, offset, count); 
//得到非法词汇列表，这个可以在数据库或web.config中读取出来 
string pattern = @"(非法词汇1|非法词汇2|非法词汇3)"; 
string[] s = pattern.split(new string[] { "|" }, stringsplitoptions.removeemptyentries); 
foreach (string s1 in s) 
{ 
sbuffer = sbuffer.replace(s1, "**"); 
} 
byte[] data = system.text.utf8encoding.utf8.getbytes(sbuffer); 
responsestream.write(data, 0, data.length); 
} 
#endregion 
} 