Getting error / crashed when internet connection lost in visual basic 2008.
Public Function GetIP() As String
Dim uri_val As New Uri("http://example.com/")
Dim request As HttpWebRequest = HttpWebRequest.Create(uri_val)
request.Method = WebRequestMethods.Http.Get
Dim response As HttpWebResponse = request.GetResponse()
Dim reader As New StreamReader(response.GetResponseStream())
Dim myIP As String = reader.ReadToEnd()
response.Close()
Return myIP
End Function
Related
I am getting TWO exceptions. The first one in the regular code and the second into the exception handling block.
I have this function (below) that supposed to change user settings in a Web API using PUT method. Everything runs fine until the point that I try to get a response from the web request. Then it raises the first exception (unknown) and when I try to handle the error I get a second exception "Object reference not set to an instance of an object".
As far as I know normally what will cause this error is the attempt of getting a response of an unassigned web request, but in this case it IS assigned and the Uri is valid. All the credentials for authorization are correct too.
This is my code:
Try
Dim webRequest As System.Net.HttpWebRequest
webRequest = System.Net.HttpWebRequest.Create(InternalSettings.APIurl + "/config")
webRequest.Headers("Authorization") = InternalSettings.APIpwd
webRequest.Headers("API-Application-Key") = InternalSettings.APIkey
webRequest.Method = "PUT"
webRequest.ContentType = "application/x-www-form-urlencoded"
Dim postData As String = ""
postData += "SaveAllCustomersData=false"
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
Dim dataStream As Stream = webRequest.GetRequestStream()
dataStream.Write(byteArray, 0, byteArray.Length)
dataStream.Close()
'The next line will raise an unknown exception
Dim myHttpWebResponse As HttpWebResponse = webRequest.GetResponse
Dim responseReader As StreamReader = New StreamReader(myHttpWebResponse.GetResponseStream())
Dim responseData As String = responseReader.ReadToEnd()
responseReader.Close()
webRequest.GetResponse().Close()
Catch ex As WebException
'The next line will raise a "Object reference not set to an instance of an object" exception
Dim resp = New StreamReader(ex.Response.GetResponseStream()).ReadToEnd()
Dim obj = JsonConvert.DeserializeObject(resp)
Return False
End Try
If you are using basic authentification you can try something like this:
Dim strUrl As String = InternalSettings.APIurl + "/config"
Dim request As WebRequest = DirectCast(WebRequest.Create(strUrl), HttpWebRequest)
Dim strResponse As String = ""
Dim byteAuth() As Byte = Encoding.UTF8.GetBytes(InternalSettings.APIkey & ":" & InternalSettings.APIpwd)
Dim strPost As String = "SaveAllCustomersData=false"
Dim bytePost() As Byte = Encoding.UTF8.GetBytes(strPost)
request.ContentType = "application/x-www-form-urlencoded"
request.Method = "PUT"
request.Headers.Add("Authorization", "Basic " & Convert.ToBase64String(byteAuth))
Using sw = New StreamWriter(request.GetRequestStream())
sw.Write(bytePost, 0, bytePost.Length)
sw.Flush()
Using response As HttpWebResponse = request.GetResponse()
Using sr = New StreamReader(response.GetResponseStream())
strResponse = sr.ReadToEnd()
End Using
End Using
End Using
I'm making a web request that completes successfully most of the time (target$ is a URL). But occasionally my code throws a valid exception, 404 not found, if the URL target$ doesn't exist, and execution stops. The code:
Sub scrape(target$)
Dim request As WebRequest = WebRequest.Create(target$)
Dim response As WebResponse = request.GetResponse()
Dim dataStream As Stream = response.GetResponseStream()
' Open the stream using a StreamReader for easy access.
Dim reader As New StreamReader(dataStream)
' Read the content.
Dim responseFromServer As String = reader.ReadToEnd()
txtResponse.Text = ""
txtResponse.Text = responseFromServer
' Clean up the streams and the response.
reader.Close()
response.Close()
end sub
The exception, if thrown, happens in the second line, "Dim response...". So I tried adding a "try-catch" as shown.
Sub scrape(target$)
Dim request As WebRequest = WebRequest.Create(target$)
Dim response As WebResponse = request.GetResponse()
Try
Dim dataStream As Stream = response.GetResponseStream()
Catch
exflag = True
End Try
' Open the stream using a StreamReader for easy access.
Dim reader As New StreamReader(dataStream)
' Read the content.
Dim responseFromServer As String = reader.ReadToEnd()
txtResponse.Text = ""
txtResponse.Text = responseFromServer
' Clean up the streams and the response.
reader.Close()
response.Close()
end sub
But now when I try to compile the code, VisualStudio tells me that "datastream is not declared" and the compile fails.
What am I doing wrong and how do I catch the exception when it's thrown?
Thanks...
I would need to send a POST request to a remote server, which requires a Bearer Authorization.
this is my VB.NET code:
Public Shared Function syncAsana() As String
Dim result As String
Try
Dim token As String = "TOKEN"
Dim uri As String = "https://URL/api/1.0/tasks"
Dim postData As String = "assignee=email¬es=TEST_NOTES&name=NOME 1&projects=123985"
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
Dim request As WebRequest = WebRequest.Create(uri)
request.Method = "POST"
request.PreAuthenticate = True
request.Headers.Add("Authorization", "Bearer " & token)
request.ContentType = "application/x-www-form-urlencoded"
request.ContentLength = byteArray.Length
Dim dataStream As Stream = request.GetRequestStream()
dataStream.Write(byteArray, 0, byteArray.Length)
dataStream.Close()
Dim response As WebResponse = request.GetResponse()
Using dataStream1 As Stream = response.GetResponseStream()
................
result = responseFromServer
End Using
response.Close()
Catch ex As Exception
result = ex.Message
End Try
Return result
End Function
the problem is that I always get the error The underlying connection was closed: An unexpected error occurred on a receive
the same request made with jquery / ajax or with curl works.
I have tried both from the local server launched by visual studio, and by putting the code on the production server.
could you tell me where i'm wrong?
I am getting an error:
400 Bad request
when trying to create a project via vb.net in asana.
Note: The ApiKey I am using works when I use it in other vb.net code to get the list of workspaces which is where I got my workspace ID.
Here is my code; I would be grateful for any insight...
Public Sub main()
Dim address As Uri
address = New Uri("https://app.asana.com/api/1.0/projects")
Dim ApiKey As String
ApiKey = "<my api key>"
Dim basicAuthenticationString As String
basicAuthenticationString = Convert.ToBase64String(New UTF8Encoding().GetBytes(ApiKey + ":"))
' Create the web request
Dim request As HttpWebRequest
request = DirectCast(WebRequest.Create(address), HttpWebRequest)
request.Headers("Authorization") = "Basic " & basicAuthenticationString
request.Method = "POST"
request.ContentType = "application/json"
Dim postData As String = "{""data"":[{""name"":""Randy Test Project"",""notes"":""Randy Test Project Notes"",""workspace"":5272875888767}]}"
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
request.ContentLength = byteArray.Length
Dim dataStream As Stream = request.GetRequestStream()
dataStream.Write(byteArray, 0, byteArray.Length)
dataStream.Close()
Dim response As HttpWebResponse = request.GetResponse()
Console.WriteLine(CType(response, HttpWebResponse).StatusDescription)
dataStream = response.GetResponseStream()
Dim reader As New StreamReader(dataStream)
Dim responseFromServer As String = reader.ReadToEnd()
Console.WriteLine(responseFromServer)
reader.Close()
dataStream.Close()
response.Close()
Exit Sub
End Sub
I was able to figure it out, My address needed to be:
Dim address As Uri = New Uri("app.asana.com/api/1.0/teams/22956925957833/projects")
Then my postData needed to be:
Dim postData As String = "{""data"":{""name"":""Randy Test Project"",""notes"":""Randy Test Project Notes""}}"
Alternatively, you can specify the team or workspace in the post data. When you get a 400 Bad Request the body of the error response will tell you which fields were actually missing/invalid.
How do you set Site values in FTPWebRequest in VB.net
In Chilkat we set values like below
Dim ftp As New Chilkat.Ftp2()
Dim success As Boolean
success = ftp.Site("lrecl=1000 recfm=fb cy pri=1 sec=1")
Dim request As FtpWebRequest = FtpWebRequest.Create("ftp://ftp.sunet.se/pub/www/Mosaic/Mosaic/Windows/README")
request.Credentials = New NetworkCredential("anonymous", "really")
request.Method = System.Net.WebRequestMethods.Ftp.DownloadFile
Dim response As FtpWebResponse = request.GetResponse()
Dim reader As New StreamReader(response.GetResponseStream())
Dim text As String = reader.ReadToEnd()
response.Close()
MessageBox.Show(text)