how to use BeginInvoke and EndInvoke on a ListView to add items so that it doesn't lock up the UI as the items are being added in a loop? Is it something like:
Public Delegate Sub DoLoadList()
Private Sub LoadList()
For i As Integer = 1 To 1000
[Code].....
I have a filesystewatcher object. On it`s event it runs a procedure which fills a treeview with a data. I had problems with treeview methods, but when I run them using invoke method everything is ok. But I still have one problem. When I load the form for the first time, everything works fine. But, when I then close the form (me.dispose, me.close), and load it once again, when Filesystemwathcer start the procedure i have an exception "invoke or begininvoke cannot be called on a control until the window handle has been created" trying to run a treeview.invoke method?
View 9 RepliesI've got the following code:
[code]...
The problem is that, when I call the "SetStatusBarText" sub from another thread, InvokeRequired is True (as it should be), but then my threads stall on the Me.Invoke statement - pausing execution shows them all just sitting there, not actually invoking anything.
What is Platform Invoke Service (P/Invoke)?
View 1 RepliesWe have a UI with a progressbar. I know how to invoke, safely, the control from which it was not created from a thread. there are threads being processed in a threadpool, all of which calls an "agent" (which is a notifier to raise an event back to the UI to then increase the progressbar). an "agent" is set as a property in a State object, which is then passed into a method which will be executed on the ThreadPool. so, I invoke on the UI the method to update the progressbar, but the bar does not seem to update at all (screen frozen) and it takes a very very long time for it to execute. without threading, no problem.
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I have a Tcp Client which I created on an application form but now I would like to create a class for it.
My prob is that when I check for any incoming data, I used to start a new thread. When this new thread finds any incoming data, I call a sub which invokes the form and everything works smooth.
This is what I am talking about,[code...]
How would I be able to do the same from a class? Or I dont have to create a separate thread when using classes?
I'm using the following code to close a form (Inherits System.Windows.Forms.Form) but it sometimes hangs up at the Invoke() ...
Private Delegate Sub closeFormDelegate()
Private Sub closeForm()
If myForm.InvokeRequired Then
[code].....
i'am trying to open the autocomplete-window from a textbox without typing chars into the box.Normaly the autocompletewindow opens only if you type in a character, but this means, you have to know the first char.Is there any way to open the autocompletewindow without the first character? For example at the mouseover event of the textbox?
View 3 RepliesI have written a simple pdf file manager which works perfectly on a Windows XP desktop.I have installed it on a 2003 Terminal Server and am getting the following error when I start itFile does not begin with '%PDF-'.
The opening form has the following load code
Private
Sub Form1_Load(ByVal
sender As System.Object,
ByVal e
[code].....
The file exists and will open using the Adobe pdf reader on the Terminal Server. I have Administrator rights so it is not a permission issue.
It was pretty simple in VB6 to invoke the 'click' event of a command button (i.e.; btnNext_Click). I am having difficulty trying to do the same think in VS2008.
I am getting errors at line btnNext_Click(): Error1Argument not specified for parameter 'e' of 'Private Sub btnNext_Click(sender As Object, e As System.EventArgs)'.
Error2Argument not specified for parameter 'sender' of 'Private Sub btnNext_Click(sender As Object, e As System.EventArgs)'.
i got a background worker that has the following code in the do work.... one of the things i want to do is to add rows if theres none available ...but i got an error saying i need to do a safe call thread...i already read about it but im stuck i put control.invoke, but that gives me an error too saying Error1Reference to a non-shared member requires an object reference.what can i do to add rows safely?
vb.net
Private Sub BackgroundWorker2_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker2.DoWork
If DataGridView2.Rows.Item(num).Cells.Item(0).Value = "" Then
Control.Invoke(DataGridView2.Rows.Add(1))
I want to develop an EDI 837 Professional project and I don't understand from where to start. If anybody knows about this & have worked on it then please help me & give me advice where do I start from ?
View 1 RepliesIn My project, i have Multiple Forms in which same Function name with return values. i like to convert the String name to Form Object and try to call the user defined function in the corresponding form from the Module I am using vb.net 2008 .
View 3 RepliesI am trying to invoke the onclick function in an html page that displays content. I am using the httpwebreqest control and not a browser control. I have traced the function and tried to find the link it calls but looking at the code below I tried inserting the link into the browser with the main url but it does not work.
[Code]...
I am using following code to edit and update field in my databse table. But it does not cast any effect on database.
Dim drCurrent As DataRow
drCurrent = DbResultDataSet.tblResult.Rows(0)
MsgBox(drCurrent.Item("PaperID"))
drCurrent.BeginEdit()
drCurrent.Item("PaperID") = "433"
drCurrent.EndEdit()
TblResultTableAdapter.Update(DbResultDataSet.tblResult)
anyone out there assist me with a basic tutorial on how to begin programming of smart devices?What can I do with the Microsoft SDK?
View 1 RepliesI'm a systems analyst and the company I work for likes to automate as much as they can. Recently I've been getting a lot of questions like "can we automate this in any way?" and I have no idea. I've done automation for Word, Excel, adobe reader and a terminal viewer they use but that was mostly done with code already written by some one else here. If there is a program you want to automate, do you just go to the programs website and hope they have a developers section or is there a standard way to use program dlls for automation? I'd also like some good resources on COM objects if anyone has some, I believe that is how most automation is done, correct?
View 5 RepliesI would like to use the transactions commit/rollback against a sql server rdbms within a VB 2010 module. I understand how these can be executed within a Transact-SQL session, but cannot seem to be able to code them correctly within VB as these are more like DDL statements.
View 4 RepliesHow to implement resize begin and end on controls the way a Form does. I had the idea that this can be accomplished using windows messages API (WM_ENTERSIZEMOVE and WM_EXITSIZEMOVE) but most of the samples I've seen so far are for windows. The reason for this is because I have a control that needs to re-render an image. The controll is inside a split container. The split container has only the Resize event. Is there any way this can be done?
View 4 RepliesI want to read ALL text between specific <b1> and </b1> tags + hide the tags, example text:As part of the Visual Studio product range, Microsoft created a set of free development environments for hobbyists and novices, the Visual Studio 2005 Express series. One edition in the series is Visual Basic 2005 Express Edition, which was succeeded by Visual Basic 2008 Express Edition in the 2008 edition of Visual Studio Express.[8]The Express Editions are targeted specifically for people learning a language. They have a streamlined version of the user interface, and lack more advanced features of the standard versions. On the other hand, Visual Basic 2005 Express Edition does contain the Visual Basic 6.0 converter, so it is a way to evaluate feasibility of conversion from older versions of Visual Basic. [code]I want to use .rtf because i need to save color etc.
View 11 RepliesPrivate Sub DataGridView1_CellBeginEdit(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellCancelEventArgs) Handles dgvProduct.CellBeginEdit
ComboBox1.Visible = True
ComboBox1.Select()
ComboBox1.Focus()
ComboBox1.Text = DataGridView1.Item(0, DataGridView1.CurrentRow.Index).Value
End Sub I have a datagridview, all i want to happen is when i click on the cell (on columns(0)) the combo Box will appear (combo box is with item) so i will select the items on list.. after selecting the item it will display on the current datagridview cell. now my problem is when im Begin Edit, the focus should go to the Combo Box in order to select the item by Keyboard and not by mouse..
I have a few lines in an rtb. e.g:
1. radjesh
2. radjesh
3. radjesh
now I select the 3 lines and press a button. The output should be (for example):
<start>
<line>1. radjesh</line>
<line>2. radjesh</line>
<line>3. radjesh</line>
</start>
I want to create a very simple (to begin with) database driven application. The company I work for have very kindly said they will host any SQL database I create, they have a remote server that we all connect to for files etc.
So I want to be able to create an SQL database that they can host and have my colleagues and I install the application local on our machines.
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I have an HTML string and in that string are certain variables that I need to replace with database values. The variable names are dynamic but all begin with the characters "@@" (just two ampersands, no quotes). Is there a way to get all the words in a string that start with "@@"? I'm assuming you would use regular expressions, but not sure how to begin.
View 2 RepliesI have a test problem i Zach VB 2010 chapter 17 #10, Doughnut solution. a have the form made, exit coded but not sure where to
View 9 RepliesI'm working with random access files. I created a module and in it put the
Structure PersonData
Dim Name as String
Dim Age as Integer[code]....
The problem is strange... it will let me input string lengths of 3 for Person.Name and Person.Description and it will save correctly, however, the moment I try and lengthen the string (or even if it's longer than 3 to begin with), I get a 'bad record number' error.
basicly im attempting to make a key encoder type application that i want to begin encrypting keystrokes when the user focuses on a password field . Is it possible for a windows forms application to do this and if so how can it be done ?
View 4 RepliesI have a vb-2008 program that contains a (listview) control.
View = details
AllowColumnReorder = true
Lets say the table has 3 columns (a,b,c) and 1 row of data.
a b c
1 2 3
I want the user to be able to re-arrange the columns (by dragging the column headers) before printing the contents of the table.
c a b
3 1 2
Statements like:
.. ListViewX.Columns(2).Text
.. ListViewX.Columns.Item(2).Text
.. ListViewX.Items(0).SubItems(2).ToString
Give the column-name (c) and cell-contents (3) of the origional table .. not the (3rd) column (b) of the re-arranged table.
How can i get the column-name and cell-contents of the (3rd) column of the re-arranged table?
Do I really have to go through all this just to find out what item has been selected in a ListView?
[Code]...
Isn't there something fundamental like this? Is absolutely everything in VB.NET buried beneath a colossal heap of bureaucracy?
i am developing a point of sales system. currently i have my product code scanned and displayed in a listview. lets say that i have 5 product codes displayed in my first listview. By clicking on a button, how can i use these codes to call upon the details (prices, product name, etc.) of the corresponding codes and display in another listview?
i am using Visual Basic 2008 and MsAccess as my database. who have the idea on solving my question. (As my last thread has not been answered at all..