Hi! So I have this weird error in my application which I cannot solve for quite a while now..
Intro:
My application will be running on a tablet using celluar network for its data connection with a remote Microsoft SQL server. When the application starts it checks for an available internet connection using a public function called "
GetInternetConnection". This will return either True or False and saves the last attempt to my.settings.IsConnected. Everytime a connection is required this function is called and when no internet acces is available it will show a dialog with a message that the user must connect to the internet. A retry button on that dialog does the check again and if it then succeeds it will continue on to the actual code where the connection with internet is required.
- The first form that is loaded has a menubar with one button named "Checklists"
- The form has a sub that loads a specified usercontrol and displays it inside the mainform
- Everytime the user presses a button the "GetInternetConnection" function is called and must be valid to be able to continue
Problem:
Scenario 1 (Internet available):
Application runs fine, no errors
Scenario 2 (Internet available on startup but internet cable removed after loading):
Step 1: Run application; no problems
Step 2: Press button "Checklists"
Step 3: Function to check internet connection is called and fails because cable is removed
Step 4: Internet cable is put back in pc
Step 5: Retry button is pressed and the check internet function is called again and passes.
Step 6: The usercontrol "Checklists" is loaded and shown in the mainform
Step 7: Unplug Internet cable
Step 8: Do something that requires internet in that usercontrol
Step 9: Function to check internet connection is called and fails because cable is removed
Step 10: Internet cable is put back in pc
Step 11: Retry button is pressed and the check internet function is called again and passes.
Step 12: Code is executed which requires internet and it an error occurs "The connection has been disabled"
Scenario 3 (Internet available on startup but internet cable removed after loading):
Step 1: Run application; no problems
Step 2: Unplug internet cable
Step 3: Press the button "Checklists"
Step 4: Function to check internet connection is called and fails because cable is removed
Step 5: Internet cable is put back in pc
Step 6: Retry button is pressed and the check internet function is called again and passes.
Step 7: Usercontrol "Checklists" is loaded succesfully; no errors
Remarks:
So my question is.. Why do I get the "The connection is disabled" error in scenario 2 but not in scenario 3 (and first part of scenario 2). its the same code and same check? Im going mad haha
Source code for CheckInternetConnection:
Code:
Public Function GetInternetConnection() As Boolean
My.Settings.IsConnected = False
Try
My.Settings.IsConnected = My.Computer.Network.Ping("www.digitaalwachtboek.nl", 5000)
Catch ex As Exception
My.Settings.IsConnected = False
End Try
Return My.Settings.IsConnected
End Function
Source code for mainform:
Code:
Private Enum LoadControl As Integer
Dashboard = -1
Conf_Checklists = 0
End Enum
Private Sub BarButtonItem1_ItemClick(sender As Object, e As DevExpress.XtraBars.ItemClickEventArgs) Handles BarButtonItem1.ItemClick
DisplayControl(LoadControl.Conf_Checklists)
End Sub
Private Sub DisplayControl(CT As LoadControl)
re:
GetInternetConnection()
If My.Settings.IsConnected = False Then
Select Case CdS_OSN_Controller1.OSN_ShowRibbon(CDS_OSN.CDS_OSN_Controller.OSN_Types.RetryAbort, Color.SkyBlue, "Verbinding met internet", "Maak eerst verbinding met het internet om verder te gaan").ToUpper
Case "ABORT"
Application.Exit()
Case Else
GoTo re
End Select
End If
ProgressPanel1.Visible = True
Refresh()
Application.DoEvents()
PanelControl_Master.Controls.Clear()
Select Case CT
Case LoadControl.Conf_Checklists
LabelControl1.Text = "Checklist overzicht"
Dim p As New CONF_Checklists
With p
.Dock = DockStyle.Fill
.boot()
End With
PanelControl_Master.Controls.Add(p)
Case LoadControl.Dashboard
LabelControl1.Text = "Dashboard"
Dim p As New DashboardPage
With p
.Dock = DockStyle.Fill
.boot()
End With
PanelControl_Master.Controls.Add(p)
End Select
ProgressPanel1.Visible = False
End Sub
Private Sub Dashboard_FormClosing(sender As Object, e As FormClosingEventArgs) Handles Me.FormClosing
Application.Exit()
End Sub
Private Sub Dashboard_Load(sender As Object, e As EventArgs) Handles Me.Load
DisplayControl(LoadControl.Dashboard)
End Sub
Source code for Checklists usercontrol:
Code:
Public Class CONF_Checklists
Private Sub Edit()
re:
GetInternetConnection()
If My.Settings.IsConnected = False Then
Select Case Dashboard.CdS_OSN_Controller1.OSN_ShowRibbon(CDS_OSN.CDS_OSN_Controller.OSN_Types.RetryAbort, Color.SkyBlue, "Verbinding met internet", "Maak eerst verbinding met het internet om verder te gaan").ToUpper
Case "ABORT"
Application.Exit()
Case Else
GoTo re
End Select
End If
Dim tempid As Guid = Nothing
Try
tempid = CType(GridView1.GetFocusedRowCellValue("P_ID"), Guid)
Catch ex As Exception
Exit Sub
End Try
If tempid <> Nothing Then
Dim p As New DLG_New_Checklist
With p
.PROP_IsExisting = True
.PROP_ExistingID = tempid
End With
If p.ShowDialog = DialogResult.OK Then
boot()
End If
End If
End Sub
Public Sub boot()
Using Connection As OdbcConnection = New OdbcConnection(My.Settings.DSN)
Dim odbcCommand As OdbcCommand = New OdbcCommand("SELECT P_ID, ChecklistName, ChecklistDescription, ModifiedBy, Modified, ChecklistNamedType FROM dbo.CMS3_CHECKLISTS ORDER BY ChecklistName", Connection) With {.CommandType = CommandType.Text}
Using TekstveldAdapter As OdbcDataAdapter = New OdbcDataAdapter()
TekstveldAdapter.TableMappings.Add("Table", "Tekstveld")
TekstveldAdapter.SelectCommand = odbcCommand
Connection.Open()
Using dataSet As DataSet = New DataSet("Tekstveld")
TekstveldAdapter.Fill(dataSet)
GridControl1.DataSource = dataSet.Tables(0)
End Using
End Using
End Using
With GridView1
.Columns("P_ID").Caption = "ID"
.Columns("P_ID").Visible = False
.Columns("ChecklistName").Caption = "Titel"
.Columns("ChecklistDescription").Caption = "Omschrijving"
.Columns("ModifiedBy").Caption = "Door"
.Columns("Modified").Caption = "Gewijzigd"
.Columns("ChecklistNamedType").Caption = "Type"
.Columns("ChecklistNamedType").Group()
.ExpandAllGroups()
End With
End Sub
Private Sub BarButtonItem1_ItemClick(sender As Object, e As DevExpress.XtraBars.ItemClickEventArgs) Handles BarButtonItem1.ItemClick
Dim p As New DLG_New_Checklist
With p
.PROP_IsExisting = False
.PROP_ExistingID = Nothing
End With
If p.ShowDialog = DialogResult.OK Then
boot()
End If
End Sub
Private Sub BarButtonItem2_ItemClick(sender As Object, e As DevExpress.XtraBars.ItemClickEventArgs) Handles BarButtonItem2.ItemClick
Edit()
End Sub
Private Sub GridView1_DoubleClick(sender As Object, e As EventArgs) Handles GridView1.DoubleClick
Edit()
End Sub
Private Sub BarButtonItem4_ItemClick(sender As Object, e As DevExpress.XtraBars.ItemClickEventArgs) Handles BarButtonItem4.ItemClick
Dim tempid As Guid = Nothing
Try
tempid = CType(GridView1.GetFocusedRowCellValue("P_ID"), Guid)
Catch ex As Exception
Exit Try
End Try
If tempid <> Nothing Then
Dim p As New CONF_Questions
With p
.PROP_ChecklistID = tempid
.boot()
.Dock = DockStyle.Fill
End With
Dashboard.PanelControl_Master.Controls.Add(p)
p.BringToFront()
End If
End Sub
Private Sub CONF_Checklists_ControlRemoved(sender As Object, e As ControlEventArgs) Handles Me.ControlRemoved
boot()
End Sub
End Class
