How can I check through my application if computer is connected with internet or not (at the moment)
I need a message if net is connected.
Thanks a lot
Furqan
ping.
Dim response As Boolean = False
response = My.Computer.Network.ping(google.com)
True, you have access, false, you don't, or the world is ending because google is offline.
I would try that.
It's from VB 6, but I think you can easily convert it.
Private Declare Function InternetGetConnectedState Lib "wininet.dll" (ByRef
dwflags As Long, ByVal dwReserved As Long) As Long
Public Function IsOnline() As Boolean
Dim LFlags As Long
IsOnline = InternetGetConnectedState(LFlags, 0&)
End Function
http://bytes.com/topic/visual-basic/answers/14551-detecting-internet-connection
Internet connectivity should be handled similar to file availability.
With files, you should typically not use File.Exists() to first see if you can open a file because the results might change on you between when you perform the check and when you act on the results, let alone the difference between mere existence and read permissions. You have to handle the exceptions anyway, and so that's really a better place to concentrate your efforts.
The same is true for internet access. The best option is generally to just go and do it, and concentrate your development time on your exception handler.
Use this code :
If My.Computer.Network.IsAvailable Then
MsgBox("Computer is connected.")
Else
MsgBox("Computer is not connected.")
End If
Refer to this link.
Related
I am developing an app in VB.NET (for a customer with hardware using FTDI USB serial chip. Communication uses FTD2XX library and the respective Nuget package (FTD2XX.Net v1.2.1). After some update of Visual Studio (probably update to 17.1, but I am not sure) all functions except a few stopped working. Current VS version is 17.1.1.
For instance, it is possible to obtain number of devices attached by the FTDI driver:
Friend Declare Function FT_CreateDeviceInfoList Lib "FTD2XX.DLL" (ByRef lngNumDevs As Integer) As Integer
...
Dim ftStatus As Integer
Dim numDevices As Integer
ftStatus = FT_CreateDeviceInfoList(numDevices)
In the above snippet ftStatus result = 0 (i.e. OK) and numDevices is set to 1 (correct).
Problem starts when I want to do something serious:
Friend Declare Function FT_GetComPortNumber Lib "FTD2XX.DLL" (ByVal lnghandle As Integer, ByRef lplComPortNumber As Integer) As Integer
Friend Declare Function FT_Open Lib "FTD2XX.DLL" (ByVal iDevice As Integer, ByRef lnghandle As Integer) As Integer
Friend Declare Function FT_Close Lib "FTD2XX.DLL" (ByVal lnghandle As Integer) As Integer
Dim portHandle as Integer
Dim cpNumber as Long
For i% = 0 To 255
ftStatus = FT_Open(i, portHandle)
If ftStatus = FT_OK Then
ftStatus = FT_GetComPortNumber(portHandle, cpNumber)
ftStatus = FT_Close(portHandle)
' here is some non-essential code registering that port at index i% exists...
End If
Next
In the above code, FT_Open returns ftStatus = 0 (FT_OK) and sets a value for portHandle.
However, the next call, FT_GetComPortNumber, returns ftStatus = 1 (FT_INVALID_HANDLE) and the value passed to cpNumber is 0xFFFF (shows as positive, but in fact should be -1, I guess...). What is worse, FT_Close() also returns FT_INVALID_HANDLE and the port remains open. I verified it by trying to open the port from another app - access denied.
Sometimes it seems that FT_Write and FT_Read functions work despite this mess, but in my last try I could not any communication with the hardware at all.
I tried to use System.IO.Ports.SerialPort as possible workaround but that does not work at all. On top of that, I need to use bit-bang on RTS, because it controls supply voltage and reset of the hardware connected to the other side of the FTDI chip. Without possibility to bring RTS down for hundreds of milliseconds and then hold it up all the time I cannot control the hardware. AFAIK System.IO.Ports.SerialPort provides no possibility to do that.
What could be the solution?
After much trial and error, it appears to be a problem in compile configuration.
Open Solution properties Window and click on the Compile tab.
Then click on "Advanced Compile Options"
If the "Remove integer overflow checks" checkbox is not checked, check it!
I have no idea how an integer overflow check can garble a 32-bit number not involved in any arithmetic operation whatsoever, but this is what really happened. I consider this a bug in Visual Basic compiler used in Visual Studio 17.1.6 (and a number of previous versions), but I did not dig deeper in this topic.
#HansPassant writes:
The declarations are wrong, it must be lnghandle As IntPtr. The difference between Integer and IntPtr matter when you run the app in 64-bit mode. Prone to happen when targeting .NETCore, as likely in VS2022.
-- Hans Passant
I am in need of a little help, I'm trying to exit sub, if a test.dll is detected (test.dll is just an example), and if the dll does not exist, just continue to do the other things in the code. I'm trying to do it like this, however even when the dll exists, the sub doesn't exist. Can you tell me where I am wrong? Any advice? I am leaving an example below.
Private Declare Function GetModuleHandle Lib "kernel32" Alias "GetModuleHandleA" (ByVal lpModuleName As String) As Long
Sub main()
If GetModuleHandle("test.dll") = 1 Then
Exit Sub
Else
Do other things
End if
End sub
According to: [MS.Docs]: GetModuleHandleA function (libloaderapi.h) (emphasis is mine):
Retrieves a module handle for the specified module. The module must have been loaded by the calling process.
So:
GetModuleHandle is not the right way, as the .dll should already be loaded into the process for it to succeed (and its existence on disk would be irrelevant)
Even if it was the right way, the condition (= 1) is incorrect. Function returns (positive) handle values (the chance for such a value to be 1 is extremely slim), or NULL (0) if the .dll wasn't loaded
There are number of variants on [VBForums]: Classic VB - How can I check if a file exists? for example, taking the 1st (and simplest) one:
If Dir("test.dll") <> "" Then
Exit sub
Beware, the .dll path is important!!!
Traditionally file existence check is done by querying the file system for file's attributes.
Option Explicit
Private Declare Function GetFileAttributes Lib "kernel32" Alias "GetFileAttributesA" (ByVal lpFileName As String) As Long
Private Sub Form_Load()
If FileExists("test.dll") Then
MsgBox "DLL exists", vbExclamation
Else
'--- do other things
End If
End Sub
Public Function FileExists(sFile As String) As Boolean
If GetFileAttributes(sFile) = -1 Then ' INVALID_FILE_ATTRIBUTES
FileExists = (Err.LastDllError = 32) ' ERROR_SHARING_VIOLATION
Else
FileExists = True
End If
End Function
Accessing the attributes is (used to be) optimized in various network providers so this performed very well on network shares.
Using Dir to check for file existence might mess up with your current directory enumeration process. Generally Dir function in VB6 runtime is a very bad example of using global state for local operation -- never a good design pattern.
I'm back for more help please.
I'm still on the same project as my question a few weeks ago but stuck on another bit.
I have a multiscreen (win 7) set up and am trying to write an application that will start a number of applications and move/resize them in to the correct positions. I'm doing this as a console app in vb.net.
Following the help I received with my last question I can now start up , move , resize, close all the apps I need bar a couple.
Unfortunately I need to run two applications through Citrix.
One is an Excel sheet.
I can find the windows handle for these windows and select them and or close them but MoveWin() or SetWindowPos() doesn't seem to do anything though the title bar of the window I want to move turns blue so I know it is selecting it..
Any assistance would be greatly appreciated.
A section of the code is pasted below. I'm testing this in excel at the moment and I'll port it across to my console app once working...
Thanks...
Public Declare Function SetWindowPos Lib "user32.dll" (ByVal hwnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long
Public Const SWP_FRAMECHANGED = &H20 'Fully redraw the window in its new position.
Sub MoveWin()
Dim retval As Long
Dim hwnd As Long
Dim RetWhnd As Long
hwnd = '123456'
retval = SetWindowPos(hwnd, RetWhnd, 0, 0, 600, 400, SWP_FRAMECHANGED) ' Application.hwnd
End Sub
I am not at my home machine, so I cannot confirm this, but I am fairly certain that VB 6 has a tab on the compile dialog (last one perhaps) that has a citrix-related option checkbox. If it's not there, it might be in the project properties.
Just in case this helps someone else. I've contacted the Citrix people and they basically don't know the answer. I at least wanted to know if it was possible. Anyway as far as I can ascertain, the move command doesn't seem to be possible across the Citrix divide. The solution I've come up with is to leave the actual move part of the code in the remotely run app. That is build code in to the apps run through Citrix to look at an ini file on the local machine and receive instructions from it.
This now works great but will only work for apps that either have ability to run a container language or can be wrapped up somehow..
I need to get code to retrieve the Windows userID for the current session in VB (for Access 2013) on a 64-bit system.
I've tried the solution suggested at How to get logged-in user's name in Access vba?, but apparently this doesn't work on my 64-bit machine. I've also tried to figure out how to integrate the info at http://msdn.microsoft.com/en-us/library/office/gg278832.aspx, but I can't figure it out.
I am a NOVICE VB programmer, so I really need the actual code to do this. (I can [probably] figure out how & why the code does what it does after I see it, but I can't come up with it from scratch at this point.)
I'm hoping this answer will be helpful to others, too.
Thanks so much!
Aloha,
-pt
This should work, too:
Dim wshNet As Object
Set wshNet = CreateObject("WScript.Network")
MsgBox "Hello, " & wshNet.UserName & "!"
Set wshNet = Nothing
The answer you linked to works on a 32 bit version of access. For 64 bit versions, you need to use a pointer-safe signature:
Private Declare PtrSafe Function GetUserName Lib "advapi32.dll" Alias
"GetUserNameA" (ByVal lpBuffer As String, nSize As LongPtr) As Long
(it might work with nSize As Long - I don't have a 64-bit access at hand)
Is there any option to close the currently opened MsgBox using any code in VBA access form application?
Check out Randy Birch's response on this thread in microsoft.public.vb.general.discussion
He recommends creating a function in a .bas file called MsgBox. Doing so will cause VB to call your function rather than the built in one.
You'd then create your own MsgBox form and build in a timer to close your form after a set period of time. He provides links showing how to do this.
He also discusses a way to explicitly call the built in MsgBox function in case you need to do this.
Note: I've never done this but I've found that Randy Birch is a knowledgeable resource.
MsgBoxes are not intended to be programmatically closed, that's why it's difficult to do so. If you find yourself in a design where you must force close a MsgBox, you should probably re-evaluate your design.
I may be wrong but MsgBox is a blocking call creating a modal form so I don't think there is an easy way such as an option to do that. Do you have a specific use case for this ?
As MarkJ points out, could this could be a dialog generated by Access (rather than a VBA.MsgBox called in your own code)?
For example, when using table's 'dataview' in the Access UI to add a row you get a message, "You are about to append 1 record..." (or similar). Is this the kind of message you mean? If so, there are indeed ways to suppress them...
I used to have an easy answer to this: use the Windows Scripting Shell object, which has a 'Popup' function - a Message Box, just like the VBA MsgBox() function, with a 'SecondsToWait' parameter that provides exactly the timeout you wanted.
With CreateObject("Scripting.WsShell")
.Popup "Watch me disappear in 5 seconds", 5, Application.Name & ": test", vbInformation + vbOkCancel
End With
If you include a 'Cancel' button, it might still work: the available parameters are vbOkCancel, vbYesNoCancel, and vbRetryCancel.
If you're trying to close a dialog box you didn't initiate with your own msgBox() function call, that's unhelpful: and, as I've hinted above, the 'SecondsToWait' parameter doesn't really work these days - someone in Redmond really does't like the idea of one thread closing another thread's helpful warnings and important interruptions to the user's workflow.
However, you can launch a delayed Message Box 'Close' command using the API Timer() function - not quite 'close the currently opened MsgBox', as this requires advance warning that you intended to open it - but it's the closest thing I have, it fits into a self-contained VBA module, and I posted the code in an answer to a very similar StackOverflow question to yours.
I should warn you that the answer in question is using a sledgehammer to crack a nut, with a side order of lengthy explanation.
Rather than writing an alternative to the Access MsgBox from scratch, you might consider using (or at least studying) Arvin Meyer's Custom MessageBox Creator (downloadable on this page).
Message Boxes are meant to depict some information to the user. Hence programmatically closing is not a good design, unless you are not automating some process.
You can use sendkeys or win APIs.
I have had a similar problem; theoretically you can use the "SendKeys" function (see http://msdn.microsoft.com/en-us/library/8c6yea83%28VS.85%29.aspx). However, the MsgBox blocks the running so you cannot use the command. If you know when it going to pop up, you may run (from the script) external whshell that wait some time and then use the SendKeys. But if you know how to do that, tell me (here). Other similar possibility is to open different thread/process for it that will not be block, but I don't know if it is possible in VBA.
An easy to use Win32 based answer to actually be useful calling it. Using the below code you can easily do a timer-based PopUpBox. I like 1/2 second timer control so 2 = 1 second. Found this answer looking for the answer to this thread. Above answers don't seem to work. I want to use this when I want to show a quick message or quick answer default is normally right can be used for more.
Function Code usually in a Module:
Declare Function MessageBoxTimeout Lib "user32.dll" Alias "MessageBoxTimeoutA" ( _
ByVal hwnd As Long, _
ByVal lpText As String, _
ByVal lpCaption As String, _
ByVal uType As Long, _
ByVal wLanguageID As Long, _
ByVal lngMilliseconds As Long) As Long
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" ( _
ByVal lpClassName As String, _
ByVal lpWindowName As String) As Long
Public Function PopUpBox(Optional stMessage As String _
= "Yes or No? leaving this window for 1 min is the same as clicking Yes.", _
Optional stTitle As String = "PopUp Window", _
Optional HalfSecTimer As Long = 120, Optional lgVBmsgType As Long = vbYesNo) As Long
Dim RetVal As Long
HalfSecTimer = HalfSecTimer * 500
RetVal = MessageBoxTimeout(FindWindow(vbNullString, Title), stMessage, stTitle, lgVBmsgType, _
0, HalfSecTimer)
PopUpBox = RetVal
End Function
Call Function Code
Examples: Actual code from my database
PopUpBox "Re-Linking and Closing dB", "Closing dB", 3, vbOKOnly
intAnswer = PopUpBox("Software Lock Down Active?", "Security", 10, vbYesNo)
I know this is an old post, put it seems there is a new a easy way to do this:
Sub MessageBoxTimer()
Dim AckTime As Integer, InfoBox As Object
Set InfoBox = CreateObject("WScript.Shell")
'Set the message box to close after 10 seconds
AckTime = 10
Select Case InfoBox.Popup("Click OK (this window closes automatically after 10 seconds).", _
AckTime, "This is your Message Box", 0)
Case 1, -1
Exit Sub
End Select
End Sub
Sample code provided by: Tom Urtis
https://learn.microsoft.com/en-us/office/vba/excel/concepts/controls-dialogboxes-forms/automatically-dismiss-a-message-box