HttpRequest.Filter Propiedad
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Obtiene o establece el filtro que se usará al leer el flujo de entrada actual.
public:
property System::IO::Stream ^ Filter { System::IO::Stream ^ get(); void set(System::IO::Stream ^ value); };
public System.IO.Stream Filter { get; set; }
member this.Filter : System.IO.Stream with get, set
Public Property Filter As Stream
Valor de propiedad
Objeto Stream que se va a usar como filtro.
Excepciones
El valor de Stream especificado no es válido.
Ejemplos
En el ejemplo de código siguiente se crean dos clases QQQ1
nuevas y QQQ2
que filtran .InputStream Coloque las clases en el archivo Global.asax en un directorio de ASP.NET aplicación para que se filtren todas las entradas de todas las ASP.NET páginas web de la aplicación.
<%@ Page language="c#" %>
<%@ Import namespace="System.Text" %>
<%@ Import namespace="System.IO" %>
<script runat="server">
// This code is to be added to a Global.asax file.
public void Application_BeginRequest()
{
Request.Filter = new QQQ1(Request.Filter);
Request.Filter = new QQQ2(Request.Filter);
}
class QQQ1 : Stream
{
private Stream _sink;
public QQQ1(Stream sink)
{
_sink = sink;
}
public override bool CanRead
{
get { return true; }
}
public override bool CanSeek
{
get { return false; }
}
public override bool CanWrite
{
get { return false; }
}
public override long Length
{
get { return _sink.Length; }
}
public override long Position
{
get { return _sink.Position; }
set { throw new NotSupportedException(); }
}
public override int Read(byte[] buffer, int offset, int count)
{
int c = _sink.Read(buffer, offset, count);
for (int i = 0; i < count; i++)
{
if (buffer[offset+i] >= 'a' && buffer[offset+i] <= 'z')
buffer[offset+i] -= ('a'-'A');
}
return c;
}
public override long Seek(long offset, System.IO.SeekOrigin direction)
{
throw new NotSupportedException();
}
public override void SetLength(long length)
{
throw new NotSupportedException();
}
public override void Close()
{
_sink.Close();
}
public override void Flush()
{
_sink.Flush();
}
public override void Write(byte[] buffer, int offset, int count)
{
throw new NotSupportedException();
}
}
class QQQ2 : Stream
{
private Stream _sink;
public QQQ2(Stream sink)
{
_sink = sink;
}
public override bool CanRead
{
get { return true; }
}
public override bool CanSeek
{
get { return false; }
}
public override bool CanWrite
{
get { return false; }
}
public override long Length
{
get { return _sink.Length; }
}
public override long Position
{
get { return _sink.Position; }
set { throw new NotSupportedException(); }
}
public override int Read(byte[] buffer, int offset, int count)
{
int c = _sink.Read(buffer, offset, count);
for (int i = 0; i < count; i++)
{
if (buffer[i] == 'E')
buffer[i] = (byte)'*';
else if (buffer[i] == 'e')
buffer[i] = (byte)'#';
}
return c;
}
public override long Seek(long offset, System.IO.SeekOrigin direction)
{
throw new NotSupportedException();
}
public override void SetLength(long length)
{
throw new NotSupportedException();
}
public override void Close()
{
_sink.Close();
}
public override void Flush()
{
_sink.Flush();
}
public override void Write(byte[] buffer, int offset, int count)
{
throw new NotSupportedException();
}
}
/*____________________________________________________________________
This ASP.NET page uses the request filter to modify all text sent by the
browser in Request.InputStream. To test the filter, use this page to take
the POSTed output from a data entry page using a tag such as:
<form method="POST" action="ThisTestPage.aspx">
<%@ PAGE LANGUAGE = C# %>
<%@ IMPORT namespace="System.IO" %>
<html>
<Script runat=server>
void Page_Load()
{
// Create a Stream object to capture entire InputStream from browser.
Stream str = Request.InputStream;
// Find number of bytes in stream.
int strLen = (int)str.Length;
// Create a byte array to hold stream.
byte[] bArr = new byte[strLen];
// Read stream into byte array.
str.Read(bArr,0,strLen);
// Convert byte array to a text string.
String strmContents="";
for(int i = 0; i < strLen; i++)
strmContents = strmContents + (Char)bArr[i];
// Display filtered stream in browser.
Response.Write("Contents of Filtered InputStream: <br>" + strmContents);
}
______________________________________________________________________*/
</script>
<%@ Page language="VB" %>
<%@ Import namespace="System.Text" %>
<%@ Import namespace="System.IO" %>
<script runat="server">
' This example is meant to be added to a Global.asax file.
Sub Application_BeginRequest()
Request.Filter = New QQQ1(Request.Filter)
Request.Filter = New QQQ2(Request.Filter)
End Sub
' The class QQQ1 changes all lower case alpha chars to upper case.
Public Class QQQ1
Inherits Stream
Private _sink As Stream
Public Sub New(sink As Stream)
_sink = sink
End Sub
' All MustOverride interface members must be included.
Public Overrides ReadOnly Property CanRead() As Boolean
Get
Return True
End Get
End Property
Public Overrides ReadOnly Property CanSeek() As Boolean
Get
Return False
End Get
End Property
Public Overrides ReadOnly Property CanWrite() As Boolean
Get
Return False
End Get
End Property
Public Overrides ReadOnly Property Length() As Long
Get
Return _sink.Length
End Get
End Property
Public Overrides Property Position() As Long
Get
Return _sink.Position
End Get
Set
Throw New NotSupportedException()
End Set
End Property
Public Overrides Function Read(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer) As Integer
Dim c As Integer = _sink.Read(buffer, offset, count)
Dim i As Integer
For i = 0 To count - 1
If buffer(offset+i) >= Asc("a") And buffer(offset+i) <= Asc("z") Then
buffer(offset+i) = buffer(offset+i) - (Asc("a")-Asc("A"))
End If
Next i
Return c
End Function
Public Overrides Function Seek(ByVal offset As Long, ByVal direction As System.IO.SeekOrigin) As Long
Throw New NotSupportedException()
End Function
Public Overrides Sub SetLength(ByVal length As Long)
Throw New NotSupportedException()
End Sub
Public Overrides Sub Close()
_sink.Close()
End Sub
Public Overrides Sub Flush()
_sink.Flush()
End Sub
Public Overrides Sub Write(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer)
Throw New NotSupportedException()
End Sub
End Class
' The class QQQ2 changes all E characters to asterisks.
class QQQ2
Inherits Stream
Private _sink As Stream
Public Sub New(sink As Stream)
_sink = sink
End Sub
' All MustOverride interface members must be included.
Public Overrides ReadOnly Property CanRead() As Boolean
Get
Return true
End Get
End Property
Public Overrides ReadOnly Property CanSeek() As Boolean
Get
Return False
End Get
End Property
Public Overrides ReadOnly Property CanWrite() As Boolean
Get
Return False
End Get
End Property
Public Overrides ReadOnly Property Length() As Long
Get
Return _sink.Length
End Get
End Property
Public Overrides Property Position() As Long
Get
Return _sink.Position
End Get
Set
Throw New NotSupportedException()
End Set
End Property
Public Overrides Function Read(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer) As Integer
Dim c As Integer = _sink.Read(buffer, offset, count)
Dim i As Integer
For i = 0 To count-1
If buffer(i) = Asc("E") Then
buffer(i) = Asc("*")
End If
Next i
Return c
End Function
Public Overrides Function Seek(ByVal offset As Long, ByVal direction As System.IO.SeekOrigin) As Long
Throw New NotSupportedException()
End Function
Public Overrides Sub SetLength(length As Long)
Throw New NotSupportedException()
End Sub
Public Overrides Sub Close()
_sink.Close()
End Sub
Public Overrides Sub Flush()
_sink.Flush()
End Sub
Public Overrides Sub Write(ByVal buffer() As Byte, ByVal offset As Integer, ByVal count As Integer)
Throw New NotSupportedException()
End Sub
End Class
'____________________________________________________________________
' This ASP.NET page uses the request filter to modify all text sent by the
' browser in Request.InputStream. To test the filter, use this page to take
' the POSTed output from a data entry page using a tag such as:
' <form method="POST" action="ThisTestPage.aspx">
'<%@ PAGE LANGUAGE = VB %>
'<%@ IMPORT namespace="System.IO" %>
'<html>
'<Script runat=server>
' Sub Page_Load()
' Dim str As Stream, strmContents As String
' Dim counter, strLen As Integer
' Create a Stream object.
' str = Request.InputStream
' Find number of bytes in stream.
' strLen = CInt(str.Length)
' Create a byte array.
' Dim strArr(strLen) As Byte
' Read stream into byte array.
' str.Read(strArr,0,strLen)
' Convert byte array to a text string.
' For counter = 0 To strLen-1
' strmContents = strmContents & Chr(strArr(counter))
' Next counter
' Response.Write("Contents of Filtered InputStream: " & strmContents)
' End Sub
' </html>
</script>