Accessing The UI Thread To Change Dependency Properties In WPF?
Jul 21, 2011
I'm trying to update a dependancy property in VB.Net 4.0 inside of an Async callback. I feel like I am doing this correctly but I'm still getting the "The calling thread cannot access this object because a different thread owns it." error. Does someone see a better way of using delegates in VB.Net 4.0?
Private WithEvents myObj as CallingObject
Private Delegate Sub MyErrorDel(ByVal strError as string)
Public Property ErrorMessage As String
[code]....
Whenever ErrorMessage gets set inside of DisplayError an exception gets thrown, even though I am using the dispatcher to call DisplayError.
View 2 Replies
ADVERTISEMENT
Sep 26, 2011
I have an exceptionhandler function that basically just writes a line to a textbox on Form1. This works fine when being run normally but the second I use a thread to start a process it cannot access the property. No exception is thrown but no text is written to the textbox:
Public Sub ExceptionHandler(ByVal Description As String, Optional ByVal Message As String = Nothing)
' Add Error To Textbox
If Message = Nothing Then
Form1.txtErrLog.Text += Description & vbCrLf
Log_Error(Description)
[Code] .....
Is it possible to access a form's properties from a thread this way or would it be easier to write to a text file or similar and refresh the textbox properties every 10 seconds or so (Don't see this as a good option but if it's the only way it will have to do!).
View 2 Replies
Oct 11, 2011
As we know, one STA UI thread creats the controls only canbe accessed in the UI thread in Winform application. And we need to call control.invoke or begininvoke to run the code in the background thread.
Yes, below code in VB.Net , VS 2010 Winform project can throw the exception "Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on."
[Code]...
View 9 Replies
Feb 26, 2011
How to change all properties of a form to properties of other but don't change important properties like Owner,Handle, OwnedForms, Parent,HasChildren,Controls and ... .I have a child form that i want it to provide controls of Form.The background form provides Aero frame and child form is a transparent form in it.I want it because I want to draw buttons with system style in Aero in Windows Forms.This is my own code but it does not work good (ForeForm is child form):
For Each Propertry In ForeForm.GetType.GetProperties()
Select Case Propertry.Name
Case "AeroBackgroundEnabled", "FormBorderStyle", "TransparencyKey", "Parent", "Owner", "ShowInTaskbar", "Handle", "HasChildren", "OwnedFo[code].....
Additionaly:I wrote a great Aero Form.I don't publish current version (1.2) that supports Aero Blur,RealTime Aero Color change,extend Basic theme?
View 13 Replies
Oct 21, 2011
I am using webbrowser control to parse html.I used to have this code that works just fine
vb.net
Public Shared Sub putHtmlIntoWebBrowser(ByVal html As String)
'WebBrowser.DocumentText = html
[code].....
View 1 Replies
Apr 26, 2012
[code]I want to make the Properties Window to update the properties for X and Y at each MouseMove, so they become immediately visible for the user.
View 2 Replies
Jul 5, 2011
I have a function that is called when a file is modified in a folder. This function updates the items of a listview which is stored in the UI.Here is the function :
Private Sub FileChangeNotify()
Try
LstMoulures.Items.Refresh()
[code]....
Here is the error: "Le thread appelant ne peut pas accéder à cet objet parce qu'un autre thread en est propriétaire." (Translation : The calling thread cannot access this object because it is owned by another thread)
View 2 Replies
Feb 1, 2011
ccessing a UI object with a Thread gives an error
View 2 Replies
Aug 14, 2009
I�m having trouble accessing a flexgrid from a different thread.Basically in my main mdiParent I have some code like this, this code is triddered when the aplication receives a message from a remote client
Public Delegate Sub UpdateActionsGridStatusDelegate()
Me.Invoke(New UpdateActionsGridStatusDelegate(AddressOf frmActions.UpdateActionsGridStatus))
I also have a form called frmActions, which contains the function �UpdateActionsGridStatus�
Public Sub UpdateActionsGridStatus()
MsgBox("Actions row cnt = " & Me.flxActions.Rows.Count - 1)
End sub
If I run it from a button on the flxActions form it works fine.When I run this function from a thread it returns 0 rows!
View 5 Replies
Aug 23, 2011
I have a control which has a button named "btn1", and I want to change it's contents through a dependency property in XML, like this:
<UserControl:UserControl1 ButtonContents="Something"/>
Here's what I have:
Public Class UserControl1
Public Shared ReadOnly ButtonContentsProperty As DependencyProperty =
DependencyProperty.Register("ButtonContents",
[code]....
But how can the dependency property know what to do?
View 3 Replies
Feb 18, 2010
I've currently created the class below. For some reason though I can't access the properties I've created through my xaml style.
Public Class Ribbon : Inherits Button
Private mpopDropdown As Popup
Public Property Dropdown() As Popup
[Code].....
but they don't seem to expose the property either. I've also tagged the property as <Bindable(True)> but that didn't seem to do anything.
View 2 Replies
Apr 8, 2010
Is it possible for one class to access an array of values within another class as a readonly property of the second class? All of the examples and references on class properties imply that one can only retrieve one value by calling a class' property.
View 2 Replies
Feb 4, 2010
Accessing Properties Of Form Classes
View 1 Replies
Aug 30, 2009
If I have a custom windows service running on a server, is there anyway I can access the value of a property/variable within that service? For example, I would like to have a client vb program be able to "read" the value some variable from that service. A simple example would be the service would capture a boolean value of the success or failure of the last time it kicked off a process. I would then like to have a client windows app "connect" with the service and be able to read that boolean value.
View 3 Replies
Jan 28, 2011
I want to know the correct way to access an object that is stored as an object in another object...phew. Here is what I'm trying to do...
I'm creating a restaurant map and to keep things simple I have 3 classes -- cServer, cTable and cGuest. cTable has a property which should contain a cServer object eg
Public Property Server() As Object
'Called when the property is read
Get
[Code].....
View 2 Replies
Apr 16, 2011
im trying to access a richtextbox from another class and thread then the ui and i cant seem to get it working. I currently have the sub thats handling the the work inside of a public class and its a sharedsub, im going to be calling it from several different classes and threads but again i cant seem to get it working. the code looks like this. Public Class SharedSubs
[code]...
i would be calling sub using SharedSubs.Console("stringstring") when this is called from the ui thread it works fine but when its called from anyother thread or class its does nothing,ive confirmed it going thru this code but its not displaying anything in the textbox and its not thru an exception due to delegates either which i figured it would.
View 2 Replies
Aug 25, 2009
how to access the main ui's labels from a delegate method?
View 7 Replies
Jul 13, 2010
In my program (PassGen) i have a DataGridView control that stores passwords.But when i add more about 20,000 or more entries at the same time (using "Generate List", UI freezes up for a few minutes.I tried to add new entries from a background thread (so main thread will redraw the form), but run into exceptions How to do that?
View 1 Replies
Feb 2, 2010
I have masterpage.master.vb where I have properties, such as;
Private _SQLerror As String
Public Property SQLerror() As String
Get
[Code]....
View 3 Replies
Jun 10, 2009
I am moving from VB to C#. I am trying to loop through a collection class which is a collection of data classes but I can't seem to get the actual values out of the data class properties(find the correct code to do so). I have a method that loops through the collection class(Contacts) and saves each record(Contact). I am using reflection because my method will not know if it is Contacts class or a Customer class and so forth. Here is my code in VB(watered down)
Public Function SaveCollection(ByVal objCollection as Object, ByVal TableName as string, ByVal spSave as string)
Dim objClass as Object
[Code]....
The C# code keeps returning null. In my locals window I can see the proprties on the class on objClass and the value of the propery but I can seem to figure out how to access it through code. I used the DictionaryBase because that seems to closely match would I need to do. My data class(Contact) has a bunch or properties that match the field names in the database of the Contact Table. After I get the propInfo variable set I then set up my SQLParameter with the fieldname, datatype etc and then set the value to the propInfo.value.
View 5 Replies
Nov 1, 2011
I am trying to access MS/Word document properties without opening the file in Word. Right now I have an app that reads the document properties but it has to open the document in word. This makes it run very slowly and also makes it susceptible to crashing if the document is corrupted. In Windows Explorer, you can right-click on a word document file and select properties. The ensuing dialog box contains, in addition to the usual information, two additional tabs labelled "Summary" and "Custom" that correspond to the same tabs in the dialog box you can open from File/Properties menu in Word. I know windows explorer is not opening the document in word because there is no instance of word.exe in task manager and because it has no difficulty in obtaining this information from the file even when it cannot be opened in Word because the document has become corrupted.If anyone could help me figure out how to read custom and built-in document fields (properties) from the file without opening it in Word,
View 1 Replies
Jan 5, 2012
Im having a problem understanding if accessing httpcontext inside a shared function, without passing in the httpcontext as a parameter is thread safe?
Are the 2 functions in the util class equally thread safe?
Class foo
Sub main()
Dim qs1 = util.getQS(HttpContext.Current)
[Code]....
View 2 Replies
Nov 14, 2011
It appears that when you access My.Settings.Default in VB.NET, your thread's CurrentPrincipal changes. Consider the following code.
[Code]...
Is this expected? Is it documented anywhere? I couldn't find any references to it.It also seems to only do this the first time My.MySettings.Default is accessed, which means that a workaround might be to touch the property to initialize it before attempting to set the thread's CurrentPrincipal. Would there be any undesirable side effects to doing that?
View 1 Replies
Sep 8, 2009
I have a form with Check Boxes on it and a second form that holds functions and a Backgroundworker.When a button is pressed on the first form, the second form loads and then runs the functions that relate to the appropriate Check Boxes.Doing it this way causes the second form to become inaccessible. I decided to run my code in the Backgroundworker's DoWork event and then call the RunWorkerAsync method in my form's Activated event. Before using the Backgroundworker, everything worked fine and now it doesn't.I assume the issue is with the Backgroundworker not being able to access controls on another thread.In debug mode,it automatically throws an exception, but doesn't error out when using the Release version, making me assume it's a legal call. But, if it's a legal call, then why can't I access the controls?
View 10 Replies
Jun 22, 2009
I need to migrate from Excel 2003 VBA to Excel 2007 VBA. When Microsoft introduced Excel 2007 it removed many objects from the previous versions and added some new objects. Also it hid some properties of particular objects. These hidden properties can be viewed by going to the object browser, right clicking any object and selecting "Show Hidden Members". My problem is I need to access these hidden properties. Is there any way I can access these properties. I can successfully migrate from Excel 2003 VBa to Excel 2007 VBA with the same functionality?
View 5 Replies
May 8, 2011
I have to make a VB project for one of my college Co-Sci classes. However, I am having issues doing what I think is logically possible. Part of our project entails creating a user defined class, then create a form that then instantiates an instance of the object type. After that we are to list the item in a listbox. That is all well and good and works fine.
What I need help with is looping through each object in the listbox, getting some data from the object, then moving to the next.
I have been trying something similar to c++. For example, an object contained in a c++ array can be accessed like this:
array[index].someObjectMethod().
How would someone do something similar to that for objects contained in a VB listbox? I imagine it starts something like this:
myListBox.Items(index).
View 2 Replies
Jun 11, 2012
I have used the following code to generate buttons dynamically. I want to know how to code in such a way that if i click one button, there should be some change done to some other button in the same form. Since all the buttons are generated in the loop, i do not know how to call one button elsewhere in the code.
Private Sub random2_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim i As Integer
[Code].....
View 1 Replies
Apr 6, 2010
how to handle movement of buttons that are made in runtime. What my program does is writes the name of a button that is made in runtime, the left, and top cordinate into a textfile. When the user reopens the program it needs to load the button in the same spot. So far i have a streamreader reading the file in each line. There is a one sentence split by ",". Each of the three components are loaded into an array. how can i call the buttons it i am unsure of the name. Possible answer could include using sender, addhandler.
Private Sub LoadBuildingToolStripMenuItem1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LoadBuildingToolStripMenuItem1.Click
Dim File As OpenFileDialog = New OpenFileDialog
[Code].....
View 10 Replies
Mar 1, 2011
I'm writing a really simple file updater which downloads files off from a website and saves them. The download routine is working well, except that it freezes the project while attempting to connect to the host. Easily solved with threading except now when I try to access other form items such as text boxes, labels, form caption, it says I am not doing it in a safe manner and prompts an interrupt in debug. I did some reading on it and I'm still not sure what to do, I'm very new to vbnet and it is still a little confusing to me.
Error: Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on.
Imports System.Threading
Imports System.Net
Imports System.IO
[code]....
View 8 Replies
Oct 5, 2011
I have a problem with this program
Form1.vb
Imports System.ComponentModel<br/><br/>Public Class Form1
Public Delegate Sub updatePB(ByVal value As Integer)
Private bgworker As BackgroundWorker = New BackgroundWorker
[code]....
View 6 Replies
