Use A Delegate To Update Text Of Main Form From DoWork Event Of BackgoundWorker?
Mar 26, 2010How would you create and use a delegate to update the text of the main form from the DoWork event of a backgoundWorker?
View 4 Replies
ADVERTISEMENT
Possible To Update UI From BackgroundWorker DoWork Event?
Sep 22, 2010I have seen others with a similar issue but not quite what I was looking for. In the backgrounderworker class dowork event I create an instance of a new class and call one of it's function. Previously, I had this code in a windows.form.timer tick event and would pass a delegate in as one of the parameters which would allow the function and other functions it calls within the class to call a method on the form to update a datagrid on the GUI. Is there a way to do this within the dowork event? I need this because the function I call from dowork calls other functions and I want each of those functions to log information in the GUI datagrid.
View 3 RepliesDelegate To Update Form Controls Not Working?
Sep 25, 2009I have used delegates multiple times over the years but for some reason this very simple code isn't working:Form has one button and on textbox. Simply trying to update the textbox from another thread and although it looks fine it's not working.[code] the parameter is being passed to the DoSomething, the UpdateTextboxText is being run and gets the correct string. But the textbox itself remains blank and I'm stumped.
View 1 RepliesC# - Delegate Event To Form Without Creating Circular Reference
Jun 19, 2012I have a class that is in an assembly due to being required for other projects that I'm currently working on. One class lets call it Class Factory, creates a group of controls which require click event handlers to be attached, I have algorithms which determine polymorphic behavior based on certain features but that is relatively irrelevant.
Due to the event handler having to open up a specific form that isn't part of my assembly, and that form requiring this "Factory" class. Without creating circular reference is there any way I can essentially "delegate" the handler event for the form to define? As a simple work around I have had to maintain two separate classes, one in the project with the form and one in the assembly.
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.Width = 1500
Dim panel As New Panel
panel.Location = New Point(0, 0)
panel.Size = New Size(1000, 200)
[Code] .....
Changing Current Calendar In DoWork Event
Oct 26, 2009I am trying to execute the following line of code within the DoWork event of a BackgroundWorker object: [code]
View 1 RepliesDetail Bound Form Updates Main List Form, But Does Not Update Data
Jan 29, 2010I have a main form with datagridview containing a list of contacts:
VB
Public Class Form1
Private Db As New DataClasses1DataContext
Private Sub Form1_Load
[Code]....
After saving, I get the correct message ("Saved"), and the DataGridView in the first form gets updated in real time.
But... when I take look at the data (or close and reopen the forms) the data in the database (SQL server) have not changed! What happens!
Calling Showdialog() On A Form - From The Main Form's OnLoad Event Makes The Modal Dialog Go Away After A Few Seconds?
Aug 7, 2009I'm having an interesting issue that I can't reproduce on a different project, but can consistently on this one. I have no clue what might be causing it, but am hoping that someone may have seen it before.
I have a main form, from which I run a series of checks. On this form, I have a listview control. Because of some issues with the refreshing of this listview control, I had to create my own messagebox. It's just a form that displays some text ( it also happens to look nicer than MsgBox; in my opinion, anyways ). It's been working great for months, until recently.
My problem is that on my main form's load event, I run this check, which returns an error within a try/catch block. I then call my custom messagebox with a message. It in turns calls it's ShowDialog() function.
In any other situation ( after the main form has been loaded ), I have no problems. The messagebox goes on the screen and behaves appropriately ( ie: waits for my input and acts as a modal dialog ( stops execution of my main form's thread ) ). However, on this onload event, my messagebox comes up and goes away almost immediately afterwards.
I've traced it all the way to the showdialog() call. For no explicable reason, it appears to skip right over this call, without me doing anything on the form.
Here's what the inner trace looks like ( when I put a breakpoint on the onclosing event for this messagebox form ):
CODE:
Update The Button Text On A Form From A Backgroundworker.do_work Event, And It Failed With The Usual Cross-thread Exception Message?
Nov 14, 2011I tried to update the button text on a form from a backgroundworker.do_work event, and it failed, with the usual cross-thread exception message.However, by pure chance, I also tried to update text in a system.windows.form.toolstripstatuslabel also from this backgroundworker.do_work event, and it DOES work. Question: why is this? Is it perhaps because theres some kind of implicit shared behaviour with system.windows.form.toolstripstatuslabel?
View 4 RepliesMake The Custom Exception Thrown In BackGroundWorker DoWork Event The Error In RunWorkerCompletedEventArgs?
Oct 6, 2010Let's say a custom exception is thrown in the DoWork event for a backgroundworker. How do I pass the custom exception to the backgroundworker so that it ends up being the e.Error in the RunWorkedCompletedEventArgs?
View 1 RepliesNotifies The Main Thread Via A Delegate Sub?
Mar 3, 2012i have a background thread when it is done doing its task it notifies the main thread via a delegate sub it seems if the main thread is "busy" then the background thread hangs waiting for the main thread. if this is normal, which i assume it is my background thread, starts another thread, and this 2nd background thread makes the delegate call is this bad practice?
View 2 RepliesChange Form Focus In The Main Load Event?
Jul 7, 2009I have an application with a main menu.
File , Menu B, Menu C ....
-1
-ServiceMenu
When the user run the application I would like to show the File menu->ServiceMenu form and the main menu should be allways on the background. I try the following: From the main menu load events call the ServiceMenu routin.
Private Sub ServiceMenu()
Dim szt As New sztetelek
Me.AddOwnedForm(szt)
[code]....
My problem the following the new ServiceMenu (szt form) show in the right position but cannot get focus. My user have to click on it to the form gets the focus however if the user click the File-ServiceMenu this forms works well and get the focus.I think the main menu get back the focus (If i press the ALT the File menu dropdown .... )
Set The Label.text With BackgroundWorker Dowork Sub?
Jun 13, 2011have a formthat hasa BackgroundWorker,on the do_work event i exe an SP:
Dim result As IAsyncResult = cmd.BeginExecuteNonQuery()
Dim rowCount As Integer = cmd.EndExecuteNonQuery(result)
Display Application Name In The Text Property Of Main Form?
Feb 25, 2012I am wanting to display my Application name in the text property of my main form. This is the code I a using:
Me.text = My.Application.Info.Title & " " & My.Application.Info.Version.ToString I am wanting to change the name of my project from when I first created it and for this new name to be displayed via the above code.
I have changed the name under the properties setting, yet it is not updating.
Delegate To Update A List Box?
Mar 27, 2012I've been fooling around with this for two hours and getting nowhere. I want to update a list box on a form with some text. Unfortunately the event that calls for the update is a timer which gives me a cross thread error.The listbox relies on a combo box which tells it the number of items to display. Here's my sub that performs the update.
Public Sub EventUpdate(ByVal EventMsg As String)
Dim DateTimeStamp As String = Format(DateAndTime.Now, "MM/dd hh:mm:ss")
With lbxEvents
[code].....
One Trigger A Click Event In A UserControl From The Main Form's Tab Index Control That Contains An Instance Of The User Control?
Jan 5, 2011The code is listed below which hopefully illustrates what I'm trying to do:[code]....
View 12 RepliesVS 2010 : Trigger Event In Usercontrol To Trigger Sub In Main Form?
Feb 18, 2012I have a main form that has a dynamically generated treeview and also a panel control. Depending on the selection made within the treeview the panel docks 1 of three diffrent usercontrols which are full sub forms(done for ease of modifing design of sub form rather than layering panels on top of panels).Upon button click withing usercontrol i wish to trigger event within main form.For example delete button wich then triggers to remove current selected node from treeview. code for 1 of three diffrent user controls
Dim ctrlQ As New QuoteUC(TrViewQuotation.SelectedNode)
PnlSubFormDock1.Controls.Add(ctrlQ)
Code for delete button for which i need to raise event.
If MsgBox("Are you sure you wish to delete this customer ?", vbYesNo, "Delete Record") = vbYes Then
Deletecustomer(n)
End If
Update Form On Asynchronous Control Event?
Jan 31, 2012A few weeks ago I wrote a wrapper for the ServiceController control to enhance and streamline the base ServiceController. One of the changes I made was to add a monitoring component using the System.Threading.Timer object. On any change of status, an event is raised to the parent class. The actual monitoring works fine, but when the event is handled in the main form, my program abruptly ends - no exceptions, no warning, it just quits. [code]...
View 1 RepliesUpdate Text In A Label Wiyh Datagridview Event?
Mar 15, 2010I have a datagrid, Records_tablesDataGridView. when i enter values into it's two columns and hit enter i want to update a label text to show how many records are in the records_table.I assumed that i would find an event in the datagridview properties that i would be able to use. so far no luck.
View 4 RepliesRaise An Event Through Delegate Method In .net?
Sep 16, 2009may i know how to implement a delegate method into my project> currently i am using the serial port polling method by using a timer to read from the serial port, but now i am changing the method to delegate part.i have the code for the delegate part updating to the text box control but how do i modify it to update the mainform with my program codes.
The part for the delegate code is here
'---Event handler for the DataReceived event---
Private Sub DataReceived( _
ByVal sender As Object, _
ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) _
[code]....
[.NET 2010] Using The Raise Event + Delegate?
Oct 9, 2010So I'm using a Open Source DLL file.The DLL-file got a "Public Custom Event" named: Hashed and I don't really know how to use it.The example is as follow: (C# Language)
c.Hashed += delegate (object o, TorrentCreatorEventArgs e) {
Console.WriteLine("Current File is {0}% hashed", e.FileCompletion);
Console.WriteLine("Overall {0}% hashed", e.OverallCompletion);
Console.WriteLine("Total data to hash: {0}", e.OverallSize);
};
I've tried to convert it to VB.NET but it doesn't work.How can I get that code above working?
Multicast Delegate: Represents A Multicast Delegate; That Is, A Delegate That Can Have More Than One Element In Its Invocation List?
Jan 30, 2010from the documentation we have this: Multicast Delegate: Represents a multicast delegate; that is, a delegate that can have more than one element in its invocation list.
so am i right to say that Multicast delegate is no different from a normal delegate other than the fact that it has arguments. so System.Action is a 'normal' delegate whereas System.Action(T)(Byval obj as T) is a multicast delegate?
C# - How To Get Actual EventHandler Delegate Instance From An Event
Nov 5, 2010In C#, I could do something like this:
EventHandler handler = this.SomeEvent;
...which would allow me to, for example, do:
Delegate[] attachedHandlers = handler.GetInvocationList();
In VB.NET, I can't seem to figure out how to do a similar thing.
This doesn't work:
Dim handler As EventHandler = Me.SomeEvent
...due to the following error:
Public Event SomeEvent(sender As
Object, e As EventArgs)' is an event,
and cannot be called directly. Use a
'RaiseEvent' statement to raise an
event.
But this doesn't work either: [Code] So how can I actually get an EventHandler from an event in VB.NET? The only idea that's immediately coming to mind is to use reflection, but that seems pretty ridiculous.
Use ItemCreated Event To Update Text Of A Label Control Contained In A Formview?
Nov 4, 2011How can I replace the text of a label control contained in a formview?[code]...
View 2 RepliesVisual Studio Shortcut To Auto-Add Event Delegate Methods
Sep 2, 2009In C# adding event handler methods is very easy. You just type "object.event +=" and then press tab twice. Is there anything like this for VB projects? Note: This is for dynamically created controls or controls that are not declared WithEvents.
View 1 RepliesForms :: Update Data In A Text Box On Form 1 From A Textbox On Another Form?
May 15, 2011I was using 2 forms, the first one has general data capture and the second one is a calendar form. On Form1 I have mulitple windows controls. A Textb ox and beside a Calendar button. When I click on a Calendar Command button, it should open calendar form and once the user selects the date, the date should be placed in the text box on the form1. Identical to this on Form1 I need multiple textboxes that needs date to be captured.I cannot use a global variable for this as I need to validate mulitple text boxes. To explain this, I have a Transaction Date and Date Received. I need to validate whether Transaction date is prior Date Received or not? I dont want to use several global variables b'coz I might need multiple validations as above. Please help me on this.
View 6 RepliesDelegate - BeginInvoke - EndInvoke - Clean Up Multiple Async Threat Calls To The Same Delegate?
Feb 9, 2010I've created a Delegate that I intend to call Async.
[Code]...
Get A Error" Method 'Private Shared Sub Ping Does Not Have A Signature Compatible With Delegate 'Delegate Sub ?
Jun 1, 2010Code:
Public Class SendPings
Shared Sub New()
AddHandler Post.Saved, AddressOf Post_Saved[code].....
I get a error" Method 'Private Shared Sub Ping(item As BlogEngine.Core.IPublishable, itemUrl As System.Uri)' does not have a signature compatible with delegate 'Delegate Sub WaitCallback(state As Object)'.
Update The Main Exe And Related Files In The App Dir?
Nov 30, 2010what methods use to update the main exe and related files in the app dir?
im using a seperate exe which runs with admin priviledge which downloads and replaces files as necessary.
my app downloads a text file and checks the version in that. if newer than settings.version then it runs the updator.exe and then closes.
the file downloaded also contains links to all new updates. the updator reads from this file then downloads as neccessary. then deletes the file and closes
Add Text From Form Into Listview (update)?
Nov 3, 2011I have a 3rd windows form opened and I have 2 textboxes to add Username and Password as well as a button that says add account. Username is named as Email2 and Password is named as Pass2 and the button is addaccount2. The forms are named Form 1 Form 2 and Form 3. I have a listview in form2 that has columns with names and im trying to get it to when you fill in the info on Form3 the username and pass and click the Add account button it will put it in the listview box but I would like it to be so username would be under the username column and password to be under password column under Form2 in the listview.
View 2 RepliesUse The Update In The Main Class To Access The List?
Jan 15, 2012i need to use the update in the main class to access the list in the footballadmin and then display each in a list box but i cant get it to work.
Imports Football
Public Class FootballAdmin
Private fTeam As List(Of FootballTeams)
[Code]......
