Wpf - Binding TextBox To A Value That Is Updated From A Different Thread?
Apr 20, 2011
I tried to increment a value as long as I press a button. The incremented value is connected via binding to a TextBox. The problem occures when I update the underlaying integer. I get an exception that another Thread owns it.
I had this - in the CURRENTCHANGED event of my BINDING SOURCE.
Private Sub vendorBS_CurrentChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles vendorBS.CurrentChanged If Me.CMCStarting Then Exit Sub vendorBAL_C.vendorUpdate() End Sub
This calls a sub in the class vendorBAL_C that does this
Private Sub SaveData() _adapter.Update(_vendortable)
[code]....
The vendorUpdate sub calls two .Update's on my SQL Data Adapter.Only the first one is getting saved._vendortable gets saved - changes to _vendorcapabilitiestable does not.Those two DATATABLES are getting created by
To add just a tad complexity to all this I'm making changes to _vendorcapabilitiestable through a filtered binding source in the UI.
capabiltiesBS.DataSource = vendorBAL_C.capabilitiesTable . . . Private Sub CapabiltiesTreeView_AfterSelect(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles
[code]....
I tried calling .EndEdit's on my binding source - no change.Changes to the second table are not being saved.
I have a DataGridView control in my Windows Forms Application. I am adding rows to the grid using a background thread. I change the form's cursor to Waitcursor when the process starts and back to Default when it ends. This works well for the form, but not for the grid. When the form's cursor is changed back to default, the grid's cursor does not change, although the cursor over the rest of the form does.
I am updating the grid from a background thread? (The cursor is being changed from the UI thread directly). The background process raises an event, the handler checks the InvokeRequired property of the grid and decides if it needs to "Invoke" the method again from the main thread. So, in effect the actual UI update happens from the appropriate thread. I am not sure if this means that I am "using a background thread" or not.
I have an initialize function that loads data into my textbox NameTextBox, and then I add an "s" to the name. I then click the Save button that executes SaveButton_Click when debugging the value for NameTextBox.Text is still the original string (FirstName) and not (FirstNames).
Page_Load(sender, e) Info = GetMyInfo() Initialize()
If this is a stupid question, then let me know. I can't just figure it out.First of all, this is my question. How do I detect the changed value on those text boxes?I have an idea that I create a another string values that have the original values and compare them right before saving or form closing event. This sample just have 3 text boxes, but I have 50 + text boxes on my one form. I can do it that way, but that is not really smart idea.Can I use abcDB.SubmitChanges() to detect any data changes on text boxes?
Dim sqlQuery = (From obj in abcDB.HelloWorld Select obj.Fname, obj.Lname, obj.PhoneNumber).FirstOrDefault() me.textboxFname.text = sqlQuery.Fname
I got this form with 2 textboxes and 2 buttons, when clicking each button, the corresponding textbox should show 1, problem is none of these textboxes show anything
here's the code in form1
Imports System.Threading Public Class Form1 Dim mc As New mycl
With the DataGridView I'm used to just populate them with a list of some object, using the DataSource property. Now I want to just display properties from a single object, and I'm a bit confused on how to do it.. The object is updated through an API event, and I want to select some of the properties for displaying in the DataGridView, to look like this:.where "ValueX" is the name of the properties.Now, what would be my options for binding this to the DataGridView, such that property changes are automatically updated. Since an update also must invoke the control, does that mean I must reassign all bindings, or what logic is necessary in this case?
should I bind to an array, arrayList, stringList, dataTable etc? I guess I'm not sure which type of source will allow binding. Or if I should perhaps build the columns and cells of the grid and populate them "one-by-one" to the properties of the object?
I would expect to see the path.Path include the new record, however, I also notice that tempnextgen also include the new record. Can anyone help me out on this issue? Why the tempnextgen got updated as well, how to prevent this unexpected operation?
In one application, I need use 4 simultaneous threads.When the threads finished, I need to update the text of a TextBox.So, I create 4 Textbox, and I wanna the threads change the text to FINISHED.Each thread change one distinct TB.I use this "example"
Dim Terminados As Integer = 0 Private Sub frmEnviarMensagem_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Timer1.Enabled = True Timer1.Start()
[code]....
The problem is, I have an error in the red lines.The error is: INVALIDOPERATIONEXCEPTION "Cross-Thread operation not valid: Control tbPlaca1 Accessed from a thread other than the thread it was created on."I don't use cross threading. Each TB only was accessed for the correspondent thread, and for the "main program".
"Cross-thread operation not valid: Control 'Panel1' accessed from a thread other than the thread it was created on." The reason I am getting this error is because I am opening up a new form and then calling these three things:
Panel1.Show() Label1.Show() Label2.Show()
why I get this error message because it doesn't occur normally if I open Form2 after closing Form1, it only occurs when I open Form2 after closing Form4.
When my client try to connect to server I'm getting this error : Cross-thread operation not valid: Control 'l_users' accessed from a thread other than the thread it was created on.
Private Sub _socketManager_onConnectionAccept(ByVal SocketID As String) Handles _socketManager.onConnectionAccept l_Users.Items.Add(SocketID) End Sub
Would anyone be able to help me here please. I'm fairly new to VB.net and threading so im just trying to figure out what is happening.When I debug this I am getting the error thread operation not valid: Control 'ProgressBar1' accessed from a thread other than the thread it was created on.
I'm a little lost as to why the error is occuring or how to fix it. I've had to put the progress bar in a separate thread otherwise the GUI crashes
My understanding is that thread.join will suspend the execution of code on the calling thread until the spawned thread finishes or is aborted...
With that in mind, I tried this:
For i = 1 to 50 threads = New Thread(AddressOf test) threads.IsBackground = True threads.SetApartmentState(ApartmentState.STA)
[CODE]...
However, the rest of the code runs when the loop finishes, not waiting for all the spawned threads to finish. Since the rest of the code needs the threads to finish (otherwise the rest will error).
I am trying to create a basic webpage that will check a column of a database table to see if a "UPC Code" is taken already, to prevent duplicate use. I'm fairly new at .NET programming, but have built asp pages before. I'm just stumped :/
I have a textbox that a user can type in a number. The page successfully checks to see if the textbox is blank and reports the error, and if there is a value, it's supposed to bind that textbox number to a gridview to see which Item# it's associated with. But for some reason, my code is not binding the value of the textbox to the gridview.
I have a DataGridView that is bound to a BindingSource. Below this are a group of textboxes that are associated with each column in the DGV. I tried to bind the textboxes to the BindingSource but realized their was no DataSource property for the textboxes. How can I bind them?
I have been searching for an answer for this for almost a week now, and I can't seem to find a way to do this. I would think it is a relatively simple thing...
I have a ListView, and one GridViewColumn contains TextBox items. I want to put a Label right underneath the ListView, and fill it with the sum of the items in all the TextBoxes. Whenever someone changes a value in any of the TextBoxes, the sum should change, too.[code]...
have a TextBox with binding like below Items is table name and ItemName is field name i am using DataSet binding TextBox with ItemsBindingSource - ItemName i am type in textbox rose milk i want to store in propercase like Rose Milk how can i do?
I have a table on an sql server and am creating a form to manage the records in the table. On the form I have a combobox to navigate between records and am using this code to populate a dataset and the combobox...
[code]...
Also on the form I have various textboxes to edit the data for each record, and when the combobox selection changes, the data in the textboxes change. I know I can update the selected record when the contents of a textbox changes, but is there a way to bind the textboxes to the current record? What is the perfered best) method of handling this?
I am running Windows 7 and have an application that has a textbox bound to a Property in a Custom Class that Implements IEnumerable.When I call Raise Event to update the textbox it will only work the first time.However, the application works on every other OS I have tested on (XP, Vista). Also if my custom class does not implement IEnumerable it works correctly.Is this a bug? Am I doing something wrongform with a textbox and a button. The Textbox is bound to the Total Property in the class.
Public Class Form1 Private oDS As New DataSource Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
I have written an application that loads a form - frmCad as well as AutoCad. It does this via a class which detects when AutoCad quits.
Friend Class CadApp Private WithEvents AppObject As AcadApplication... Private Sub AppObject_BeginQuit(ByRef Cancel As Boolean) Handles AppObject.BeginQuit RaiseEvent Quit() End SubEnd Class
My main class loads frmCad as well as CadApp.
Public Class Cad Private WithEvents frmCad As CadForm Private WithEvents app As CadApp... Public Sub ShowForm() If frmCad Is Nothing Then frmCad = New CadForm frmCad.Visible = True End Sub... Private Sub app_Quit() Handles app.Quit frmCad.Dispose() frmCad = Nothing .... End Sub
When I debug the program, it stops at frmCad.Dispose()The program continues to execute, but all the code after it fails to work.Looking more carefully I get an error message which contains:-Cross-thread operation not valid: Control 'Autocad' accessed from a thread other than the thread it was created on.
My error:Cross-thread operation not valid: Control 'label2' accessed from a thread other than the thread it was created on. I want to be able to give my Public RunBot() sub access to edit Labels, buttons, etc without an error.
My problem is Cross-thread operation not valid: Control 'statusHO' accessed from a thread other than the thread it was created on.
System.InvalidOperationException was unhandled Message="Cross-thread operation not valid: Control 'statusHO' accessed from a thread other than the thread it was created on." Source="System.Windows.Forms" StackTrace:
[Code]...
i used it and it works fine then. but as it is mentioned its not a good practice to use it. So what should i do? is it ok if i use this as i am not able to use correct practice. Mine application is not for enterprise purpose. its just my class project, and it works fine even if i put application working in background. System works ok. I dont know how to correct this error.As i dont have that much knowlege of threads.
So please guide me how to fix this in correct way otherwise i am force to go for bad programming practice Please refer to Windows Mobile Developer Center > Smart Device Development Forums > Windows Mobile Development > Appendtext not working for all my code details
Saving data from textboxes to a dataset Default Values - Binding Navigator But i could not do it or didnot understand how to do it. I have a Binding Navigator created by the wizard, I want to put a value "A" in a Textbox when adding new record (press +). I had tried to use this code in txt_site_GotFocus and BindingNavigatorAddNewItem_Click
Im having some wierd behavior on a bound form in vb.net 2008. I have setup a client form, with another tab that has contacts for that client. the contacts tab has a binding navigator at the bottom, so the user can move amongst the contacts. all fields on that form are bound to a bindingsource called bsContact, using a table adapter called "ContactTableAdapter"
if i have a contact already saved, and want to modify the contact info, the form binding doesn't seem to recognize that i have changed the value of a textbox on that contact.i would think that if a textbox is bound to a bindingsource, then if the value of that textbox changes, the bindingsource would know about it, but it doesn't. The dataset.HasChanges returns false, and my save wont happen. (see code)so, when i hit the movenext on the bindingnavigator, it changes to record 2...i change a value on a textbox...i hit the save button on my form....no update will happen.
Update: I noticed that if i am on the tab with the multiple contacts, and i change a textbox on the form, then i MOVE TO ANOTHER RECORD, then the dataset recognizes that there was a change, and the update happens. Why doesn't the textbox immediately notify the dataset that a change is happening?