WebException Конструкторы

Исходный код:

WebException.cs

Исходный код:

WebException.cs

Исходный код:

WebException.cs

public:
 WebException();

public WebException ();

Public Sub New ()

Примеры

В следующем примере по умолчанию WebExceptionвозникает исключение .

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

Комментарии

Конструктор без параметров инициализирует новый экземпляр WebException класса . Свойство Message инициализируется системным сообщением, описывающим ошибку. Это сообщение учитывает культуру текущей системы. Свойства InnerException и инициализируются Response в null. Свойство Status инициализировано значением параметра RequestCanceled.

Исходный код:

WebException.cs

Исходный код:

WebException.cs

Исходный код:

WebException.cs

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)

Параметры

Примеры

В следующем примере возникает исключение , WebException указывая сообщение об ошибке.

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

Комментарии

Экземпляр WebException инициализируется со значением Messagemessageсвойства . Если message имеет значение null, свойство инициализируется Message в предоставленное системой сообщение. Свойства InnerException и инициализируются Response в null. Свойство Status инициализировано значением параметра RequestCanceled.

См. также раздел

• Exception

Исходный код:

WebException.cs

Исходный код:

WebException.cs

Исходный код:

WebException.cs

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)

Параметры

Атрибуты

ObsoleteAttribute

Комментарии

Этот конструктор реализует ISerializable интерфейс для WebException класса .

См. также раздел

• ISerializable

Исходный код:

WebException.cs

Исходный код:

WebException.cs

Исходный код:

WebException.cs

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)

Параметры

Примеры

В следующем примере создается WebException , указывая сообщение об ошибке WebExceptionStatusи .

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

Комментарии

Экземпляр WebException инициализируется со Message значением свойства , message а Status свойство — значением status. Если message имеет значение null, свойство инициализируется Message в предоставленное системой сообщение. Свойства InnerException и инициализируются Response в null.

Исходный код:

WebException.cs

Исходный код:

WebException.cs

Исходный код:

WebException.cs

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)

Параметры

Примеры

В следующем примере создается исключение путем WebException указания сообщения об ошибке и вложенного исключения.

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

Комментарии

Экземпляр WebException инициализируется со Message значением свойства , message а InnerException свойство — значением innerException. Если message имеет значение null, свойство инициализируется Message в предоставленное системой сообщение. Свойства InnerException и инициализируются Response в null. Свойство Status инициализировано значением параметра RequestCanceled.

См. также раздел

• Exception

Исходный код:

WebException.cs

Исходный код:

WebException.cs

Исходный код:

WebException.cs

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)

Параметры

Примеры

В следующем примере создается WebException , указывая сообщение об ошибке WebExceptionStatusи .

// 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()

Комментарии

Экземпляр WebException инициализируется со Message значением messageсвойства , свойству InnerException присваивается значение , свойству Status — значение innerException, свойству — значение status, а свойству Response — значение response. Если message имеет значение null, свойство инициализируется Message в предоставленное системой сообщение.