WebException Constructors
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Initializes a new instance of the WebException class.
Overloads
WebException() |
Initializes a new instance of the WebException class. |
WebException(String) |
Initializes a new instance of the WebException class with the specified error message. |
WebException(SerializationInfo, StreamingContext) |
Obsolete.
Initializes a new instance of the WebException class from the specified SerializationInfo and StreamingContext instances. |
WebException(String, WebExceptionStatus) |
Initializes a new instance of the WebException class with the specified error message and status. |
WebException(String, Exception) |
Initializes a new instance of the WebException class with the specified error message and nested exception. |
WebException(String, Exception, WebExceptionStatus, WebResponse) |
Initializes a new instance of the WebException class with the specified error message, nested exception, status, and response. |
WebException()
- Source:
- WebException.cs
- Source:
- WebException.cs
- Source:
- WebException.cs
Initializes a new instance of the WebException class.
public:
WebException();
public WebException ();
Public Sub New ()
Examples
The following example throws a default 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
Remarks
The parameterless constructor initializes a new instance of the WebException class. The Message property is initialized to a system-supplied message that describes the error. This message takes into account the current system culture. The InnerException and Response properties are initialized to null
. The Status property is initialized to RequestCanceled.
Applies to
WebException(String)
- Source:
- WebException.cs
- Source:
- WebException.cs
- Source:
- WebException.cs
Initializes a new instance of the WebException class with the specified error message.
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)
Parameters
- message
- String
The text of the error message.
Examples
The following example throws a WebException by specifying an error message.
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
Remarks
The WebException instance is initialized with the Message property set to the value of message
. If message
is null
, the Message property is initialized to a system-supplied message. The InnerException and Response properties are initialized to null
. The Status property is initialized to RequestCanceled.
See also
Applies to
WebException(SerializationInfo, StreamingContext)
- Source:
- WebException.cs
- Source:
- WebException.cs
- Source:
- WebException.cs
Caution
This API supports obsolete formatter-based serialization. It should not be called or extended by application code.
Initializes a new instance of the WebException class from the specified SerializationInfo and StreamingContext instances.
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)
Parameters
- serializationInfo
- SerializationInfo
A SerializationInfo that contains the information required to serialize the new WebException.
- streamingContext
- StreamingContext
A StreamingContext that contains the source of the serialized stream that is associated with the new WebException.
- Attributes
Remarks
This constructor implements the ISerializable interface for the WebException class.
See also
Applies to
WebException(String, WebExceptionStatus)
- Source:
- WebException.cs
- Source:
- WebException.cs
- Source:
- WebException.cs
Initializes a new instance of the WebException class with the specified error message and status.
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)
Parameters
- message
- String
The text of the error message.
- status
- WebExceptionStatus
One of the WebExceptionStatus values.
Examples
The following example throws a WebException by specifying an error message and a WebExceptionStatus.
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
Remarks
The WebException instance is initialized with the Message property set to the value of message
and the Status property set to the value of status
. If message
is null
, the Message property is initialized to a system-supplied message. The InnerException and Response properties are initialized to null
.
Applies to
WebException(String, Exception)
- Source:
- WebException.cs
- Source:
- WebException.cs
- Source:
- WebException.cs
Initializes a new instance of the WebException class with the specified error message and nested exception.
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)
Parameters
- message
- String
The text of the error message.
- innerinnerException
- Exception
A nested exception.
Examples
The following example throws a WebException by specifying an error message and nested exception.
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
Remarks
The WebException instance is initialized with the Message property set to the value of message
and the InnerException property set to the value of innerException
. If message
is null
, the Message property is initialized to a system-supplied message. The InnerException and Response properties are initialized to null
. The Status property is initialized to RequestCanceled.
See also
Applies to
WebException(String, Exception, WebExceptionStatus, WebResponse)
- Source:
- WebException.cs
- Source:
- WebException.cs
- Source:
- WebException.cs
Initializes a new instance of the WebException class with the specified error message, nested exception, status, and response.
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)
Parameters
- message
- String
The text of the error message.
- innerinnerException
- Exception
A nested exception.
- status
- WebExceptionStatus
One of the WebExceptionStatus values.
- response
- WebResponse
A WebResponse instance that contains the response from the remote host.
Examples
The following example throws a WebException by specifying an error message and a WebExceptionStatus.
// 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()
Remarks
The WebException instance is initialized with the Message property set to the value of message
, the InnerException property set to the value of innerException
, the Status property set to the value of status
, and the Response property set to the value of response
. If message
is null
, the Message property is initialized to a system-supplied message.