WebException Constructor (String, Exception, WebExceptionStatus, WebResponse)
Assembly: System (in system.dll)
public WebException ( string message, Exception innerException, WebExceptionStatus status, WebResponse response )
public WebException ( String message, Exception innerException, WebExceptionStatus status, WebResponse response )
public function WebException ( message : String, innerException : Exception, status : WebExceptionStatus, response : WebResponse )
Parameters
- message
The text of the error message.
- innerException
A nested exception.
- status
One of the WebExceptionStatus values.
- response
A WebResponse instance that contains the response from the remote host.
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 a null reference (Nothing in Visual Basic), the Message property is initialized to a system-supplied message.
The following example throws a WebException by specifying an error message and a WebExceptionStatus.
// 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.
Encoding ascii = Encoding.get_ASCII();
String requestPage = "GET /nhjj.htm HTTP/1.1\r\nHost: "
+ connectUri + "\r\nConnection: Close\r\n\r\n";
ubyte byteGet[] = ascii.GetBytes(requestPage);
ubyte recvBytes[] = new ubyte[256];
// Create an 'IPEndPoint' object.
IPHostEntry hostEntry = Dns.Resolve(connectUri);
IPAddress serverAddress = (IPAddress)hostEntry.get_AddressList().
get_Item(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.get_Length(), (SocketFlags)0);
// Receive the information sent by the server.
int bytesReceived = connectSocket.Receive(recvBytes,
recvBytes.get_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.
get_Length(), (SocketFlags)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();
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.