WebException Costruttori
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Inizializza una nuova istanza della classe WebException.
WebException() |
Inizializza una nuova istanza della classe WebException. |
WebException(String) |
Inizializza una nuova istanza della classe WebException con il messaggio di errore specificato. |
WebException(SerializationInfo, StreamingContext) |
Obsoleti.
Inizializza una nuova istanza della classe WebException dalle istanze di SerializationInfo e StreamingContext specificate. |
WebException(String, WebExceptionStatus) |
Inizializza una nuova istanza della classe WebException con il messaggio di errore e lo stato specificati. |
WebException(String, Exception) |
Inizializza una nuova istanza della classe WebException con il messaggio di errore e l'eccezione annidata specificati. |
WebException(String, Exception, WebExceptionStatus, WebResponse) |
Inizializza una nuova istanza della classe WebException con il messaggio di errore, l'eccezione annidata, lo stato e la risposta specificati. |
- Origine:
- WebException.cs
- Origine:
- WebException.cs
- Origine:
- WebException.cs
Inizializza una nuova istanza della classe WebException.
public:
WebException();
public WebException ();
Public Sub New ()
Esempio
Nell'esempio seguente viene generata una classe predefinita WebException.
try
{
// A 'Socket' object has been created.
Socket^ httpSocket = gcnew Socket( AddressFamily::InterNetwork,SocketType::Stream,ProtocolType::Tcp );
// The IPaddress of the unknown uri is resolved using the 'Dns::Resolve' method.
IPHostEntry^ hostEntry = Dns::Resolve( "http://www.contoso.com" );
IPAddress^ serverAddress = hostEntry->AddressList[ 0 ];
IPEndPoint^ endPoint = gcnew IPEndPoint( serverAddress, 80 );
httpSocket->Connect( endPoint );
Console::WriteLine( "Connection created successfully" );
httpSocket->Close();
}
catch ( SocketException^ e )
{
String^ exp = e->Message;
// Throw the WebException with no parameters.
throw gcnew WebException;
}
try
{
// A 'Socket' object has been created.
Socket httpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
IPHostEntry hostEntry = Dns.Resolve("http://www.contoso.com");
IPAddress serverAddress = hostEntry.AddressList[0];
IPEndPoint endPoint = new IPEndPoint(serverAddress, 80);
httpSocket.Connect(endPoint);
Console.WriteLine("Connection created successfully");
httpSocket.Close();
}
catch(SocketException e)
{
String exp = e.Message;
// Throw the WebException with no parameters.
throw new WebException();
}
Try
' A 'Socket' object has been created.
Dim httpSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
' which leads to the 'SocketException' exception.
Dim hostEntry As IPHostEntry = Dns.Resolve("http://www.contoso.com")
Dim serverAddress As IPAddress = hostEntry.AddressList(0)
Dim endPoint As New IPEndPoint(serverAddress, 80)
httpSocket.Connect(endPoint)
Console.WriteLine("Connection created successfully")
httpSocket.Close()
Catch e As SocketException
Dim exp As [String] = e.Message
' Throw the WebException with no parameters.
Throw New WebException()
End Try
Commenti
Il costruttore senza parametri inizializza una nuova istanza della WebException classe. La Message proprietà viene inizializzata in un messaggio fornito dal sistema che descrive l'errore. Il messaggio prende in considerazione le impostazioni di cultura correnti del sistema. Le InnerException proprietà e Response vengono inizializzate in null
. La proprietà Status viene inizializzata su RequestCanceled.
Si applica a
.NET 9 e altre versioni
Prodotto | Versioni |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
UWP | 10.0 |
- Origine:
- WebException.cs
- Origine:
- WebException.cs
- Origine:
- WebException.cs
Inizializza una nuova istanza della classe WebException con il messaggio di errore specificato.
public:
WebException(System::String ^ message);
public WebException (string message);
public WebException (string? message);
new System.Net.WebException : string -> System.Net.WebException
Public Sub New (message As String)
Parametri
- message
- String
Il testo del messaggio di errore,
Esempio
Nell'esempio seguente viene generata una WebException specifica di un messaggio di errore.
try
{
// A 'Socket' object has been created.
Socket^ httpSocket = gcnew Socket( AddressFamily::InterNetwork, SocketType::Stream, ProtocolType::Tcp );
// The IPaddress of the unknown uri is resolved using the 'Dns::Resolve' method.
IPHostEntry^ hostEntry = Dns::Resolve( connectUri );
IPAddress^ serverAddress = hostEntry->AddressList[ 0 ];
IPEndPoint^ endPoint = gcnew IPEndPoint( serverAddress, 80 );
httpSocket->Connect( endPoint );
Console::WriteLine( "Connection created successfully" );
httpSocket->Close();
}
catch ( SocketException^ e )
{
Console::WriteLine( "\nException thrown.\nThe Original Message is: {0}", e->Message );
// Throw the 'WebException' object with a message string specific to the situation.
throw gcnew WebException( "Unable to locate the Server with 'www.contoso.com' Uri." );
}
try
{
// A 'Socket' object has been created.
Socket httpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
IPHostEntry hostEntry = Dns.Resolve(connectUri);
IPAddress serverAddress = hostEntry.AddressList[0];
IPEndPoint endPoint = new IPEndPoint(serverAddress, 80);
httpSocket.Connect(endPoint);
Console.WriteLine("Connection created successfully");
httpSocket.Close();
}
catch(SocketException e)
{
Console.WriteLine("\nException thrown.\nThe Original Message is: "+e.Message);
// Throw the 'WebException' object with a message string specific to the situation.
throw new WebException("Unable to locate the Server with 'www.contoso.com' Uri.");
}
Try
' A 'Socket' object has been created.
Dim httpSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
Dim hostEntry As IPHostEntry = Dns.Resolve(connectUri)
Dim serverAddress As IPAddress = hostEntry.AddressList(0)
Dim endPoint As New IPEndPoint(serverAddress, 80)
httpSocket.Connect(endPoint)
Console.WriteLine("Connection created successfully")
httpSocket.Close()
Catch e As SocketException
Console.WriteLine((ControlChars.Cr + "Exception thrown." + ControlChars.Cr + "The Original Message is: " + e.Message))
' Throw the 'WebException' object with a message string specific to the situation.
Throw New WebException("Unable to locate the Server with 'www.contoso.com' Uri.")
End Try
Commenti
L'istanza WebException viene inizializzata con la Message proprietà impostata sul valore di message
. Se message
è null
, la Message proprietà viene inizializzata in un messaggio fornito dal sistema. Le InnerException proprietà e Response vengono inizializzate in null
. La proprietà Status viene inizializzata su RequestCanceled.
Vedi anche
Si applica a
.NET 9 e altre versioni
Prodotto | Versioni |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
UWP | 10.0 |
- Origine:
- WebException.cs
- Origine:
- WebException.cs
- Origine:
- WebException.cs
Attenzione
This API supports obsolete formatter-based serialization. It should not be called or extended by application code.
Inizializza una nuova istanza della classe WebException dalle istanze di SerializationInfo e StreamingContext specificate.
protected:
WebException(System::Runtime::Serialization::SerializationInfo ^ serializationInfo, System::Runtime::Serialization::StreamingContext streamingContext);
protected WebException (System.Runtime.Serialization.SerializationInfo serializationInfo, System.Runtime.Serialization.StreamingContext streamingContext);
[System.Obsolete("This API supports obsolete formatter-based serialization. It should not be called or extended by application code.", DiagnosticId="SYSLIB0051", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
protected WebException (System.Runtime.Serialization.SerializationInfo serializationInfo, System.Runtime.Serialization.StreamingContext streamingContext);
new System.Net.WebException : System.Runtime.Serialization.SerializationInfo * System.Runtime.Serialization.StreamingContext -> System.Net.WebException
[<System.Obsolete("This API supports obsolete formatter-based serialization. It should not be called or extended by application code.", DiagnosticId="SYSLIB0051", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
new System.Net.WebException : System.Runtime.Serialization.SerializationInfo * System.Runtime.Serialization.StreamingContext -> System.Net.WebException
Protected Sub New (serializationInfo As SerializationInfo, streamingContext As StreamingContext)
Parametri
- serializationInfo
- SerializationInfo
Oggetto SerializationInfo contenente le informazioni necessarie per serializzare il nuovo oggetto WebException.
- streamingContext
- StreamingContext
Oggetto StreamingContext contenente l'origine del flusso serializzato associato alla nuova istanza di WebException.
- Attributi
Commenti
Questo costruttore implementa l'interfaccia ISerializable per la WebException classe.
Vedi anche
Si applica a
.NET 9 e altre versioni
Prodotto | Versioni (Obsoleto) |
---|---|
.NET | Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7 (8, 9) |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
- Origine:
- WebException.cs
- Origine:
- WebException.cs
- Origine:
- WebException.cs
Inizializza una nuova istanza della classe WebException con il messaggio di errore e lo stato specificati.
public:
WebException(System::String ^ message, System::Net::WebExceptionStatus status);
public WebException (string message, System.Net.WebExceptionStatus status);
public WebException (string? message, System.Net.WebExceptionStatus status);
new System.Net.WebException : string * System.Net.WebExceptionStatus -> System.Net.WebException
Public Sub New (message As String, status As WebExceptionStatus)
Parametri
- message
- String
Il testo del messaggio di errore,
- status
- WebExceptionStatus
Uno dei valori di WebExceptionStatus.
Esempio
Nell'esempio seguente viene generato un WebException oggetto specificando un messaggio di errore e un WebExceptionStatusoggetto .
try
{
// A 'Socket' object has been created.
Socket^ httpSocket = gcnew Socket( AddressFamily::InterNetwork, SocketType::Stream, ProtocolType::Tcp );
// The IPaddress of the unknown uri is resolved using the 'Dns::Resolve' method.
IPHostEntry^ hostEntry = Dns::Resolve( "http://www.contoso.com" );
IPAddress^ serverAddress = hostEntry->AddressList[ 0 ];
IPEndPoint^ endPoint = gcnew IPEndPoint( serverAddress, 80 );
httpSocket->Connect( endPoint );
Console::WriteLine( "Connection created successfully" );
httpSocket->Close();
}
catch ( SocketException^ e )
{
Console::WriteLine( "\nException thrown.\nThe Original Message is: {0}", e->Message );
// Throw the 'WebException' object with a message string and message status specific to the situation.
throw gcnew WebException( "Unable to locate the Server with 'www.contoso.com' Uri.", WebExceptionStatus::NameResolutionFailure );
}
try
{
// A 'Socket' object has been created.
Socket httpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
IPHostEntry hostEntry = Dns.Resolve("http://www.contoso.com");
IPAddress serverAddress = hostEntry.AddressList[0];
IPEndPoint endPoint = new IPEndPoint(serverAddress, 80);
httpSocket.Connect(endPoint);
Console.WriteLine("Connection created successfully");
httpSocket.Close();
}
catch(SocketException e)
{
Console.WriteLine("\nException thrown.\nThe Original Message is: "+e.Message);
// Throw the 'WebException' object with a message string and message status specific to the situation.
throw new WebException("Unable to locate the Server with 'www.contoso.com' Uri.",WebExceptionStatus.NameResolutionFailure);
}
Try
' A 'Socket' object has been created.
Dim httpSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
Dim hostEntry As IPHostEntry = Dns.Resolve(connectUri)
Dim serverAddress As IPAddress = hostEntry.AddressList(0)
Dim endPoint As New IPEndPoint(serverAddress, 80)
httpSocket.Connect(endPoint)
Console.WriteLine("Connection created successfully")
httpSocket.Close()
Catch e As SocketException
Console.WriteLine((ControlChars.Cr + "Exception thrown." + ControlChars.Cr + "The Original Message is: " + e.Message))
' Throw the 'WebException' object with a message string and message status specific to the situation.
Throw New WebException("Unable to locate the Server with 'www.contoso.com' Uri.", WebExceptionStatus.NameResolutionFailure)
End Try
Commenti
L'istanza WebException viene inizializzata con la Message proprietà impostata sul valore di message
e la Status proprietà impostata sul valore di status
. Se message
è null
, la Message proprietà viene inizializzata in un messaggio fornito dal sistema. Le InnerException proprietà e Response vengono inizializzate in null
.
Si applica a
.NET 9 e altre versioni
Prodotto | Versioni |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
UWP | 10.0 |
- Origine:
- WebException.cs
- Origine:
- WebException.cs
- Origine:
- WebException.cs
Inizializza una nuova istanza della classe WebException con il messaggio di errore e l'eccezione annidata specificati.
public:
WebException(System::String ^ message, Exception ^ inner);
public:
WebException(System::String ^ message, Exception ^ innerException);
public WebException (string message, Exception inner);
public WebException (string? message, Exception? innerException);
public WebException (string message, Exception innerException);
new System.Net.WebException : string * Exception -> System.Net.WebException
new System.Net.WebException : string * Exception -> System.Net.WebException
Public Sub New (message As String, inner As Exception)
Public Sub New (message As String, innerException As Exception)
Parametri
- message
- String
Il testo del messaggio di errore,
- innerinnerException
- Exception
Un'eccezione annidata.
Esempio
Nell'esempio seguente viene generato un WebException oggetto specificando un messaggio di errore e un'eccezione annidata.
try
{
// A 'Socket' object has been created.
Socket^ httpSocket = gcnew Socket( AddressFamily::InterNetwork, SocketType::Stream, ProtocolType::Tcp );
// The IPaddress of the unknown uri is resolved using the 'Dns::Resolve' method.
IPHostEntry^ hostEntry = Dns::Resolve( connectUri );
IPAddress^ serverAddress = hostEntry->AddressList[ 0 ];
IPEndPoint^ endPoint = gcnew IPEndPoint( serverAddress, 80 );
httpSocket->Connect( endPoint );
Console::WriteLine( "Connection created successfully" );
httpSocket->Close();
}
catch ( SocketException^ e )
{
Console::WriteLine( "\nException thrown.\nThe Original Message is: {0}", e->Message );
// Throw the 'WebException' object with a message string specific to the situation;
// and the 'InnerException' that actually led to this exception.
throw gcnew WebException( "Unable to locate the Server with 'www.contoso.com' Uri.", e );
}
try
{
// A 'Socket' object has been created.
Socket httpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
// The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
IPHostEntry hostEntry = Dns.Resolve(connectUri);
IPAddress serverAddress = hostEntry.AddressList[0];
IPEndPoint endPoint = new IPEndPoint(serverAddress, 80);
httpSocket.Connect(endPoint);
Console.WriteLine("Connection created successfully");
httpSocket.Close();
}
catch(SocketException e)
{
Console.WriteLine("\nException thrown.\nThe Original Message is: "+e.Message);
// Throw the 'WebException' object with a message string specific to the situation;
// and the 'InnerException' which actually lead to this exception.
throw new WebException("Unable to locate the Server with 'www.contoso.com' Uri.",e);
}
Try
' A 'Socket' object has been created.
Dim httpSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' The IPaddress of the unknown uri is resolved using the 'Dns.Resolve' method.
Dim hostEntry As IPHostEntry = Dns.Resolve(connectUri)
Dim serverAddress As IPAddress = hostEntry.AddressList(0)
Dim endPoint As New IPEndPoint(serverAddress, 80)
httpSocket.Connect(endPoint)
Console.WriteLine("Connection created successfully")
httpSocket.Close()
Catch e As SocketException
Console.WriteLine((ControlChars.Cr + "Exception thrown." + ControlChars.Cr + "The Original Message is: " + e.Message))
' Throw the 'WebException' object with a message string specific to the situation.
' and the 'InnerException' which actually lead to this exception.
Throw New WebException("Unable to locate the Server with 'www.contoso.com' Uri.", e)
End Try
Commenti
L'istanza WebException viene inizializzata con la Message proprietà impostata sul valore di message
e la InnerException proprietà impostata sul valore di innerException
. Se message
è null
, la Message proprietà viene inizializzata in un messaggio fornito dal sistema. Le InnerException proprietà e Response vengono inizializzate in null
. La proprietà Status viene inizializzata su RequestCanceled.
Vedi anche
Si applica a
.NET 9 e altre versioni
Prodotto | Versioni |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
UWP | 10.0 |
- Origine:
- WebException.cs
- Origine:
- WebException.cs
- Origine:
- WebException.cs
Inizializza una nuova istanza della classe WebException con il messaggio di errore, l'eccezione annidata, lo stato e la risposta specificati.
public:
WebException(System::String ^ message, Exception ^ inner, System::Net::WebExceptionStatus status, System::Net::WebResponse ^ response);
public:
WebException(System::String ^ message, Exception ^ innerException, System::Net::WebExceptionStatus status, System::Net::WebResponse ^ response);
public WebException (string message, Exception inner, System.Net.WebExceptionStatus status, System.Net.WebResponse response);
public WebException (string? message, Exception? innerException, System.Net.WebExceptionStatus status, System.Net.WebResponse? response);
public WebException (string message, Exception innerException, System.Net.WebExceptionStatus status, System.Net.WebResponse response);
new System.Net.WebException : string * Exception * System.Net.WebExceptionStatus * System.Net.WebResponse -> System.Net.WebException
new System.Net.WebException : string * Exception * System.Net.WebExceptionStatus * System.Net.WebResponse -> System.Net.WebException
Public Sub New (message As String, inner As Exception, status As WebExceptionStatus, response As WebResponse)
Public Sub New (message As String, innerException As Exception, status As WebExceptionStatus, response As WebResponse)
Parametri
- message
- String
Il testo del messaggio di errore,
- innerinnerException
- Exception
Un'eccezione annidata.
- status
- WebExceptionStatus
Uno dei valori di WebExceptionStatus.
- response
- WebResponse
Istanza di WebResponse contenente la risposta dall'host remoto.
Esempio
Nell'esempio seguente viene generato un WebException oggetto specificando un messaggio di errore e un WebExceptionStatusoggetto .
// Send the data.
Encoding^ ASCII = Encoding::ASCII;
String^ requestPage = String::Concat( "GET /nhjj.htm HTTP/1.1\r\nHost: ", connectUri, "\r\nConnection: Close\r\n\r\n" );
array<Byte>^ byteGet = ASCII->GetBytes( requestPage );
array<Byte>^ recvBytes = gcnew array<Byte>(256);
// Create an 'IPEndPoint' object.
IPHostEntry^ hostEntry = Dns::Resolve( connectUri );
IPAddress^ serverAddress = hostEntry->AddressList[ 0 ];
IPEndPoint^ endPoint = gcnew IPEndPoint( serverAddress,80 );
// Create a 'Socket' object for sending data.
Socket^ connectSocket = gcnew Socket( AddressFamily::InterNetwork, SocketType::Stream, ProtocolType::Tcp );
// Connect to host using 'IPEndPoint' object.
connectSocket->Connect( endPoint );
// Sent the 'requestPage' text to the host.
connectSocket->Send( byteGet, byteGet->Length, (SocketFlags)(0) );
// Receive the information sent by the server.
Int32 bytesReceived = connectSocket->Receive( recvBytes, recvBytes->Length, (SocketFlags)(0) );
String^ headerString = ASCII->GetString( recvBytes, 0, bytesReceived );
// Check whether 'status 404' is there or not in the information sent by server.
if ( headerString->IndexOf( "404" ) != -1 )
{
bytesReceived = connectSocket->Receive( recvBytes, recvBytes->Length, (SocketFlags)(0) );
MemoryStream^ memoryStream = gcnew MemoryStream( recvBytes );
getStream = (System::IO::Stream^)(memoryStream);
// Create a 'WebResponse' object
WebResponse^ myWebResponse = (WebResponse^)(gcnew HttpConnect( getStream ));
Exception^ myException = gcnew Exception( "File Not found" );
// Throw the 'WebException' object with a message string, message status, InnerException and WebResponse
throw gcnew WebException( "The Requested page is not found.",myException,WebExceptionStatus::ProtocolError,myWebResponse );
}
connectSocket->Close();
// Send the data.
Encoding ASCII = Encoding.ASCII;
string requestPage = "GET /nhjj.htm HTTP/1.1\r\nHost: " + connectUri + "\r\nConnection: Close\r\n\r\n";
Byte[] byteGet = ASCII.GetBytes(requestPage);
Byte[] recvBytes = new Byte[256];
// Create an 'IPEndPoint' object.
IPHostEntry hostEntry = Dns.Resolve(connectUri);
IPAddress serverAddress = hostEntry.AddressList[0];
IPEndPoint endPoint = new IPEndPoint(serverAddress, 80);
// Create a 'Socket' object for sending data.
Socket connectSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream,ProtocolType.Tcp);
// Connect to host using 'IPEndPoint' object.
connectSocket.Connect(endPoint);
// Sent the 'requestPage' text to the host.
connectSocket.Send(byteGet, byteGet.Length, 0);
// Receive the information sent by the server.
Int32 bytesReceived = connectSocket.Receive(recvBytes, recvBytes.Length, 0);
String headerString = ASCII.GetString(recvBytes, 0, bytesReceived);
// Check whether 'status 404' is there or not in the information sent by server.
if(headerString.IndexOf("404")!=-1)
{
bytesReceived = connectSocket.Receive(recvBytes, recvBytes.Length, 0);
MemoryStream memoryStream = new MemoryStream(recvBytes);
getStream = (Stream) memoryStream;
// Create a 'WebResponse' object
WebResponse myWebResponse = (WebResponse) new HttpConnect(getStream);
Exception myException = new Exception("File Not found");
// Throw the 'WebException' object with a message string, message status,InnerException and WebResponse
throw new WebException("The Requested page is not found.",myException,WebExceptionStatus.ProtocolError,myWebResponse);
}
connectSocket.Close();
' Send the data.
Dim ASCII As Encoding = Encoding.ASCII
Dim requestPage As String = "GET /nhjj.htm HTTP/1.1" + ControlChars.Lf + ControlChars.Cr + "Host: " + connectUri + ControlChars.Lf + ControlChars.Cr + "Connection: Close" + ControlChars.Lf + ControlChars.Cr + ControlChars.Lf + ControlChars.Cr
Dim byteGet As [Byte]() = ASCII.GetBytes(requestPage)
Dim recvBytes(256) As [Byte]
' Create an 'IPEndPoint' object.
Dim hostEntry As IPHostEntry = Dns.Resolve(connectUri)
Dim serverAddress As IPAddress = hostEntry.AddressList(0)
Dim endPoint As New IPEndPoint(serverAddress, 80)
' Create a 'Socket' object for sending data.
Dim connectSocket As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' Connect to host using 'IPEndPoint' object.
connectSocket.Connect(endPoint)
' Sent the 'requestPage' text to the host.
connectSocket.Send(byteGet, byteGet.Length, 0)
' Receive the information sent by the server.
Dim bytesReceived As Int32 = connectSocket.Receive(recvBytes, recvBytes.Length, 0)
Dim headerString As [String] = ASCII.GetString(recvBytes, 0, bytesReceived)
' Check whether 'status 404' is there or not in the information sent by server.
If headerString.IndexOf("404") <> False Then
bytesReceived = connectSocket.Receive(recvBytes, recvBytes.Length, 0)
Dim memoryStream As New MemoryStream(recvBytes)
getStream = CType(memoryStream, Stream)
' Create a 'WebResponse' object.
Dim myWebResponse As WebResponse = CType(New HttpConnect(getStream), WebResponse)
Dim myException As New Exception("File Not found")
' Throw the 'WebException' object with a message string, message status,InnerException and WebResponse.
Throw New WebException("The Requested page is not found.", myException, WebExceptionStatus.ProtocolError, myWebResponse)
End If
connectSocket.Close()
Commenti
L'istanza WebException viene inizializzata con la Message proprietà impostata sul valore di , la proprietà impostata sul valore di , InnerException la Status proprietà impostata sul valore di message
status
innerException
e la Response proprietà impostata sul valore di .response
Se message
è null
, la Message proprietà viene inizializzata in un messaggio fornito dal sistema.
Si applica a
.NET 9 e altre versioni
Prodotto | Versioni |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
UWP | 10.0 |
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