I am working on a new version of my clipboard manager. I was wondering if there would be a way to copy the value of a given handle without knowing its type? The current methods I know require one person to know the type of the handle (as an example by using Marshal.PtrToStructure).
View 1 RepliesI made a program that is started and running in memory and minimized to the system tray.
When it is first launched it registers global hot keys in windows.These hot keys are used for resizing the current focused window. I'm trying to use it so you can hotkey windows to resize to half the screen, a third of the screen, etc... For instance, if I have two notepads open and notepad 1 is focused and I hit Ctrl+Shift+LeftArrow it will resize notepad1 to the left and half the size of the screen. I have notepad 2 focused and Hit Ctrl+Shift+RightArrow and resize notepad2 to the right side of the screen. So, I can easily see both windows at once.Now, I can successfully get the focused window handle when the hot key is pressed. I'm stuck at this point.
I can use the Windows API call:
[code]...
I would like to refer to a control but i do not know its number but i do know that it is a ComboBox. I was told to use this
Me.Controls("ComboBox" & 1 + i).Text
Which would get the text property of the i +1 ComboBox. However when run this I get an ullReferenceException was unhandled error. What an I doing wrong?
Is there a way to define an implicit conversion operator in VB.NET?
I can't remember ever seeing or hearing of anyone do this; but now I'm in a situation where I think it would be incredibly useful to define my own custom 'type conversion' for my class.
As an example - let's say I have my own class, 'AwesomeDataManager'. It does not inherit from DataTable, but it holds data in a similar fashion to a DataTable. I would to be able to say, 'myDataTable = CType(MyAwesomeDataManager, DataTable)' and have it execute some code inside my class that would return a populated DataTable.
Granted, I could do something like 'MyAwesomeDataManager.GetDataTable' but for the sake of integrating with an existing code base, I'd like to avoid it.
I created a Class which inherits Combobox and the listview is added . Now what I need is once the user click listview, the listview has to close and the clicked item has to added with combobox text. simply can say combobox1.text = listview.item(0).textFor closing & displaying the listview I need to handle the events. For
My Codings :========Public Class Combu_lstviewInherits ComboBoxPrivate treeViewHost As ToolStripControlHostPrivate Shadows dropdown As ToolStripDropDownPublic mylistview As New ListView
Public Sub New()mylistview.BorderStyle = BorderStyle.Nonemylistview.View = View.Detailsmylistview.HeaderStyle =
[code].....
I have defined 5 variables T1, T2, T3, T4, T5 As Double and set them all = 0. On a form I have a enter information button. Each time the button is pressed I want to assign a different variable, to a text box input. For instance, If I enter 1 that will become T1, and then if I enter 2 and press the button again, that value becomes T2.
I have tried
If T1 = 0 then
T1 = textbox.text
End if
If T1<>0 And T2 = 0 then
T2 = textbox.text
End if
I have tried to use 'else' statements and all kinds of things like that to no avail. I can get the first two variables correctly assigned but three is impossible with my current understanding. Is there a way to do this, or do I need 5 buttons, so that I can control which variable is assigned? To be correct my intent is to create an observation with three variables each time the button is pressed.
For example, the first button press will result in three variables being assigned a value other than 0; they are T1, B1, and R1. I have just begun to understand the concept of arrays and am wondering if that may be the way to go in this situation. I was just going at this in a newbie way I'm sure and trying to handle each variable type individually, and figure out all the T* variables and move onto the B* variables.
Is it possible to replace these two functions
Function f1 (s As String) As class1()
Dim a() As String = Split(s)
Dim b(UBound(a)) As class1
[code].....
I have written some C/C++ code that uses the winapi functions CreateFile WriteFile SetFilePointer etc. to read & write some large (>4 GB) binary files. Some colleagues who are more familier with Visual basic than C, want to modify some of their existing code to call my C code functions.
I have turned my code into DLLs that I have successfully called from other C programs. I have also created a small C DLL that doesn't use the winapi functions & called it from a small VB program.
What I haven't so far been unable to do is pass the HANDLE type variable between a C function that uses the winapi functions & the VB program that call it so the VB can call another of my functions & pass the HANDLE.
In my attempt to do this, the declarations in the header file for two of the functions in the C DLL are:
[Code]...
When I step through the VB code in debug mode there is no problem with calling OpenSegyRW, but at WriteToSegy I get the error message:System.Runtime.InteropServices.MarshalDirectiveException was unhandled
Message=PInvoke restriction: cannot return variants.So what am I doing wrong & is there any way to pass the winapi HANDLE type between VB & C code? BTW indents etc. get lost when I paste my message into the forum. I hope this is decipherable.
Is there a way I can catch and handle two different exceptions within the same exception type? For example:
Try
' My code
Catch ex As System.Net.WebException
End Try
I have 2 different exceptions that are System.Net.WebException. I want to handle them different ways. Problem is the catch block above catches them both. Is there a way I can determine if which of the two it is and handle them differently?
Say I have a button that creates more buttons with a random .Text property, and placed them on the form in different locations. And since these buttons are being created at runtime, I want to be able to have an event handler for all button controls on the form that makes the form's text the same as the sender's text.
View 3 RepliesI was testing article [URL] to see if I could use this to populate a listview2 with the icons from Directory.GetFiles(apath) and getDirectories. If you go into c:windowssystem32 the program will hang for about 4 mins then if you go back to windows then back to system32 you will get the error.
win32 handle that was passed to icon is not valid or is the wrong type.
When I close my form without saving I want to check if the data on my form has changed since the last time I saved the data.This peace of code, which I included at the bottom always worked fine.Except when I compade a DateTimePicker with a null value in the db.Than I get the error "Conversion from type 'DBNull' to type 'Date' is not valid."Probably on this peace of
Me.dtpVrijeDatum01.Value.Date <> CDate(reader("VrijDatumVeld01")).Date Or
Me.dtpVrijeDatum02.Value.Date <> CDate(reader("VrijDatumVeld02")).Date Or
Me.dtpVrijeDatum03.Value.Date <> CDate(reader("VrijDatumVeld03")).Date Or
Me.dtpVrijeDatum04.Value.Date <> CDate(reader("VrijDatumVeld04")).Date Or
Me.dtpVrijeDatum05.Value.Date <> CDate(reader("VrijDatumVeld05")).Date Or
The total code to check the changes is:
Private Sub CheckForChanges()
LeesCheckboxWaarde(Me.chkFacAdrIsBezAdr, intCheckFacAdresIsBez)
LeesCheckboxWaarde(Me.chkPosAdrIsBezAdr, intCheckPosAdresIsBez)
[code]....
I get the error: Conversion from type 'FileInfo' to type 'String' is not valid. This happens in between try and end try
Private Sub CopyNotes()
Dim NotesBase As String
Dim NotesTgt As String
[Code].....
I'm storing dates intoa table like:vb.net "INSERT INTO myTable (datum) VALUES ('" & Convert.ToDateTime(dgvrow.Cells(0).Value).ToString("yyyy/MM/dd hh:mm:ss") & "'" & ")", conn) This works perfectly. After storing the dates I need to load /show them into a MonthCalendar. This is where the error occurs.
[Code]...
I have the following code to use Words spellcheck feature on a RTB. Once you pick the correct word in the spellcheck box and press change I get the error on th efollwoing line
strResult = Left(objDoc.Content, Len(objDoc.Content) - 1)
I tried to use CType() but still complains.
If (Len(t.Text) = 0) Then
'nahhhhhhhhhhh
Else
[Code]....
I've got a form that acts as a progress report for a long running operation, it has a listview on it (which I might be replacing with a DGV soon) that gets updated with progress updates from a background thread that is doing all the work. The method running on the background thread raises events that the form then handles and adds the string passed in to this event to the listview. The method running on the background thread raises progress update events several times a second and for each of these updates the event handler on the form must invoke a method on the UI thread to actually add the item to the listview.
This works fine on my test PC (which has a quad core CPU and 8 GB of RAM) but others have reported that after a while the form goes to the Not Responding state so I'm assuming all of these updates on the UI thread are being requested too often for it to be able to process them all as well as user input.So I'm looking for a better solution and have come up with the following:When the background thread raises these progress updated events, instead of them being added to the listview instantly I add them to a Queue(Of String). Then every second the form would check this queue and remove any items currently in it and add them to the listview - using a Queue(Of T) instead of a List(Of T) should guarantee they come out in the correct order. Both of these operations (adding to the queue and reading/removing from it) would be done under a SyncLock block that would lock on the same object to avoid both threads trying to work with the queue at the same time, so there would still be some contention but I'm hoping it would mean the UI thread only gets busy once a second instead of potentially roughly 30 times a second as it is doing now.Does that sound like a good plan? Can anyone think of a better way of handling this?
I have been working on a program and I need it to unzip a zip file. I tried handling a zip file as a directory but that didn't work.It wouldn't hurt if I could compress files into a zip file to! But I need unzipping the file first.This is my code handling it as a directory:
Dim count As Integer = Directory.GetFiles(My.Application.Info.DirectoryPath & "Games" & game & "�00.zip").Length
MessageBox.Show(count)
It has an error saying it is not a valid directory name.
I need to get the handle of a variable. How do I do this?
DEVICE_PARAMETERS = New PresentParameters
ZeroMemory(>>Handle of DEVICE_PARAMETERS<<, Marshal.SizeOf(DEVICE_PARAMETERS))
-Ren�
Only now, I'm facing this kind of problem, i have a application that until now worked with two different cultures ENG and PT, i always knew this, and i manage to solve all problems related to parsing the numbers, but now i have to change the code, and "protect" the code to handle with others cultures. So i need tips/best way to handle different cultures, and different database culture settings.I think that i shouldn't limit the user, by setting the decimal, the grouping digit, the date time format, etc. . The application should accept the numbers in the user current culture. But this path forces me to putting everywhere the parse/tryparse method.
View 1 RepliesI am trying to use a free 3rd-party DLL (SmartWIM.DLL - Smartdeploy Imaging Component) which is, essentially, a COM wrapper for the WIMGAPI DLL for creating images of Windows drives.You have to register the dll with REgSVr32 of course Now, included with the installation package is a VBS that does a CreateObject for the SmartWIM object. When I use the VBS I can successfully create an image with the CaptureImage method.However, when I convert the same code to VB.NET and called exactly the same method, the CaptureImage method "hangs".By that I mean it successfully creates an image file but then doesn't do anything else. I am at loss to understand why it would work when run via a VBS and not work in a VB.NET Console application?
View 2 RepliesI have an event in a module, like this:
vb.net
Module Module1 Public Event Event1(Value as Boolean)End Module
I want to be able to handle this event from different forms. This is what I tried to do...
vb.net
Public Class Form1 Private Sub Event1Handler(Value As Boolean) Handles WindowsApplication1.Event1 End SubEnd Class
But I get a squiggly line under WindowsApplication1 that says Handles clause requires a WithEvents variable defined in the containing type or one of its base types. I tried to swap Module1 in, but same thing. I tried without anything in front of Event1, but still nothing.
I'm needing to make something to ALWAYS replace a "." to "," in all textboxes...
That's what I'm doing, and it's working:
Private Sub Timer1_Tick(sender As System.Object, e As System.EventArgs) Handles Timer1.Tick
For Each myControl As Control In Me.Controls
[Code]....
Im using an excel sheet as a datasource to retrieve som values that I use to draw a modified voltmeter.
However the excel sheet is DDE-linked to another application (3rd party) that updates it on a realtime basis. Every once in a while, that means my app gets a value it cant handle, or it cant access the specific cell because its being written to.
This causes my picturebox (voltmeter) to draw an error image. Now I would have thought that once it�s supposed to redo the whole operation (datafetching and drawing) that would get rid of the error image (it�s on a timer). It doesnt.So how do I solve this? If I close the form and reopen it, that takes care of the problem, but I dont want to do that.
WebBrowser Handle new window: How I can open it in a new window
View 7 RepliesI have inserted the following code depicting a procedure that can place the cursor at a particular location within a Rich textbox. However, I am unable to get the Hwnd handle to run without an error.
Would someone advise if the SendMessage arguments are correct and how do I access the RichTexBox Hwnd window handle for this procedure.
[Code]...
Ok i'm loading a webpage in the WebBrowser Control, but what i need to do is manipulate that webpage. Here is the webpage (you will probably need to take a look so you know what i'm talking about). [URL] Now i'm trying to remove the advert at the top of the webpage OR somehow get the handle of the Java applet and set it to an x and y co-ord on my form.
View 2 RepliesI want to make a screenshot of a specific window of which I know the handle. I know there is a BitBlt function but I can't get that to work with the handle, I prefer it to work even if the window is not active but I'm not sure if this is possible at all.
View 1 RepliesI have a very huge server log files like files are more than 500 to 600 mb and even some files are over 2 gb data. the files are maintained for few years. it will be maintained as is. each log file has at least 1 million lines to 20 million lines.I am looking create an application which can find a line in the text file using regex, removing duplicate entries.how these huge file can be handled in a way it works very quickly.
View 5 RepliesI have been working on an image capturing tool for a long time now & I was wondering how some of those programs are able to make an aero capture of a form.I know you can capture a window if you have it's handle by using the BitBlt, but that doesn't keep the transparancy of the aero form.Let me give you an example:I did a lot of research on google but I never found anything close to something that explains how to do it.
View 4 RepliesI'm trying to use a asynchronous UDP-Port to recieve data on a form.I manage to receive one message at a time(for each click of btnReadData), however if I do this receive in a loop (in order to continously receive new messages), my form seems to be locked.What am I doing wrong?
Public Class FPR2DIS
Delegate Sub dDataReceived(ByVal Data As String)
Dim UDPWorker As New Worker
[code].....