how to invoke methods, but how does one change a simple property?
For demonstration-sake, here's a very simple set of code that should help. Let's say I need to set the visible property from a child form, and thus, it needs to be invoked:
Friend Sub activateItem(ByVal myItem As PictureBox)
If myItem.InvokeRequired = True Then
????
[Code]....
I inherits textbox Control and I added some new properties to it .one of these properties value i want it to change it's value in desgin time when i change Name property of the new textbox
Public Class NewTextBox
Inherits TextBox
Private _txtSubName As String = String.Empty
That is the property for set or get SubstringName of Textbox
Public Property SubName() As String
Get
Return _txtSubName[code].....
that's the property i want to change it's value when i change Name property of the control.i tried to overrides Name property but it's not overridable also i trieds to overloads it but it doesn't work in desgin time.Here is something i tried but it's wronge.
Private _txtName As String = ""
Public Overloads Property Name() As String
Get[code]......
I would like to be able to set Control visual properties such as color, boarder, flat style, etc. on the base class of the control so that as I add new instances of the control, each instance inherits the visual properties of the base. I have tried using Application Settings but it appears as though I need to reference an application setting manually each time I add the control to a form. This is a Windows Form question.
View 4 RepliesI 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 RepliesIn asp.net 3.5, I am using a login control which has an id. When i set the id's font to bold, it sets all the fields to bold. for eg., the login control has "Username", "Password" & "Remember Me" and i want to set only the username & password fields bold and leave the remember field to normal.
My code is here -
<asp:Login runat="server"
id="BlogLogin" UserNameLabelText="Username" TitleText=""
MembershipProvider="EktronMembershipProvider" LoginButtonText="Login"
[Code]....
I have created a user control with some properties but when I change them in a form and build the return to the default value, Here is the code I did:
Public Property ButtonFind As Boolean
Get
Return CmdFind.Visible
End Get
Set(ByVal value As Boolean)
CmdFind.Visible = value
End Set
End Property
I have created a user control and need to know how I can let the user change some of the properties of this control at runtime and have the values persist on next startup. There are multiple instances of this control on the form.
View 10 RepliesIn vb.net 2005 how would one referance a control as variable and change it"s properties. Such as in control X visible = True. Tryed string manipulations that did't work.
View 1 Repliesi've written an app to enumerate forms + controls in a project at runtime:
it lists form names in a listbox + when a control is selected, it lists hierarchical controls in a treeview. by selecting a control in the treeview you can view its properties in a propertygrid.
here's the problem: how can i use the propertygrid to actually persistently change those properties?
at the moment you can change properties in the propertygrid but it doesn't change the control's properties, either persistently or otherwise.
here's the code. (you can download the full project at: [URL]
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ListBox1.Items.AddRange((From t As Type In Me.GetType().Assembly.GetTypes() _
Where t.BaseType Is GetType(Form) _
[Code]....
[code]For some reason I cannot change the color properties for the MonthCalendar control.[code]No matter what I change it to, it stays to its default color of white and black. Actually none of the color options work on any of the sections of the control.I am trying to hide the white border around the control and but a blue bar under the name of the month (top section).I have tried deleting the control and creating it anew on the form but no luck.It was working a couple of weeks ago.
View 1 RepliesHow 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?
I have a datagrid that I am unable to change the width setting, it always reverts back to the original setting.
To change this setting:
1. select the datagrid view tasks
2. Edit columns bound column properties
3. Select Width property
4. Width property will always revert back to the original setting.
I have check the properties settings without any luck.
I am inheriting my own DataGridView (say MyDataGridView) from the standard DataGridView control. What I want is that certain properties of MyDataGridView should have a different default value than what its base have. For example, AllowUserToAddRows, AllowUserToDeleteRows, AllowUserToResizeRows properties should have the default values of False; so that when I drag MyDataGridView into a form in the IDE, the default values shown in the properties grid should be False. Later on, if I want to change them to True from the grid, they will be set accordingly.
View 1 RepliesI can't seem to get this to work so I need a fresh set of eyes on it! I have a combobox dropdown with some names. When I select a certain name from the list, I want it to change the textbox property.I tried :if combobox1.selecteditem= "edward" thentextbox1.maxlength= "2"
View 2 RepliesHow would one invoke a readonly property?
ListView1.SelectedIndices.Count
I'm working on a Hazardous Materials label printing program. One of the options is to do an "NFPA" label. Since there are 4 values required with 4 or 6 options, the ratings are entered via radio buttons in a group box. That's working okay. I display values in the NFPA diamond as they're entered: left quadrant blue, top quadrant red, left yellow, bottom red. I'm having trouble with the label in which the rating will be displayed on top of a jpg diamond for the white. In this quadrant the text can be up to 4 characters. I can accept the text going into an adjacent block a little, but the corners of the label overlap into another quadrant/color. I reduced the font size which solved the overlap problem but the font is then too small and looks terrible. I tried to make the background of the label transparent to let the color come through correctly but that's not a valid value for label.background. I'm figuring that the transparent background is the best solution. What can I use that will accept a transparent background so the color shows through?
I'm trying to set the transparent property via label properties properties, not via code. Here's the code if it makes any difference:
Public Class NFPA
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Close()
End Sub
[code]....
In my never ending search for more knowledge, I have come across Partial Classes. I was wondering if some of the kind people who actually understand the uses could explain some of them to me. Now I know that when we create a form that we actually create a partial class which the generator rewrites when we add a control or change a property at design-time, and this allows us not to have to worry about setting up the controls ourselves.
[Code]...
This function loops all properties of an object to create the updatequery to save te object to the DB.
We had to make some changes to it because of the introduction of nullable properties. If the property is nullable we would like to check the 'HasValue' property. This does works when it has a value. When the property has no value we get an 'Non-static method requires a target'-error at the CBool-line
An other way to check the 'HasValue'-prop of a property using reflection?
Private Function GetUpdateQuery(ByVal obj As Object, ByRef params As List(Of SqlParameter), Optional ByVal excl As String() = Nothing) As String
Dim sql As String = String.Empty
[Code].....
I need some help to understand my options to get this working. I try to update a textbox control by a property-changed event from a class variable. I've digged around for a day and have a vague understanding that this can be solved in three ways:
1. Using some "if InvokeRequired", "Invoke" code in the handler method
2. By programming a special delegate class for this variable
3. By using a databinding directly linking the control (textbox) to the class event
Now.. Are these options correct? And would it be possible to get some help to show these three solutions in actual code (relevant to mine)? I can't seem to manage to sort all the information to a working code. Also, what are the pros and cons of the different solutions?
As my code stands now, it's obviously none of the above, as it gives a cross-thread error, as indicated.
[Code]...
I'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.
[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 RepliesI've reviewed the links that were offered and don't find an answer. Neither has a lot of searching helped, probably because I can't think of a reasonably short way to ask the question. I hope that I've at least found the proper forum and category.
In my VB 2010 code, I've defined a structure that has about 30 elements. I want to sum the properties (they are all singles) of two members of the corresponding collection. I understand that I can do something like:
member1.property1=member2.property1+member 3.property1 for the entire set of properties of member2 and member3 to produce a completely defined member1 What I wonder is whether or not there is a way that uses fewer lines of code - I know that I can't do:member1=member2+member3, for example.
I am using vb 2008 express and i am using the backround worker component. I am trying to change the value of progressbar1 to 50. Whenever I type progressbar1.value=50 in the DoWork section for backround worker, it says I need to use the invoke command because I am on a different thread.How do you use the invoke command to change the value of progressbar1 to 50?
View 6 RepliesI'm making a control and I am trying to finalize my design time properties grid. I have several List(of Class) items as public properties and when I click on the design time menu (while testing the control) there is the word "Collection" and a button with an ellipsis (...) that brings up a neat pop up with the buttons Add/remove and all of the public properties of the collection's class on the right hand side. Basically for a non-collection instance of a class (with public properties) I'd like a similar button to show up. I know I could put all of the properties in the main control class and group them, but I like the pop up box feature. Anyway to duplicate this? (think font grid item etc.)
View 3 RepliesI 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?
1. On the main form a scanner class is instantiated that (in the scanner's constructor) sets the scanner settings (baud rate, parity, etc) and opens the scanner for use
2. A barcode is scanned (via a scanner connected to the device in a seral port) while on the main form
3. In the scanner class, the DataRecieved event gets the needed info from the scanned code.
4. Then that info is passed back to the main form to a method RunCommandCode (which takes the scanned info as an argument)
5. On the main form the RunCommandCode calls another method CommandCodeHandler, passing the scanned info again
6. In the CommandCodeHandler sub a method is called in a Utils class (SetSelectedTab), which interacts with the form itself (determines how many tabs exist on a tab control), which is the reason for the invoke in the first place
So, before I figured out I needed to use the Invoke method (and, more specifically, that the scanner was working in a different thread), I was getting an error in step 6 on the line that got the TabControl.TabPages.Count.
[code]...
CODE:
Is there anything I need to change about this code to let me insert list items to a listbox on the UI thread?
Currently in our VB.Net windows application, C libraries are present under the 'bin' directory but we want to store it under application root directory where other forms and classes are present...How can we do this in Vb.Net 2008?
View 1 RepliesI'm working with the DevExpress XtraGrid control.I have a routine that goes thru and adds all the controls on the current form dynamically, and launches on a seperate thread the routine for a given control to initialize it to the value that will be displayed to the end-user. Some of the controls are displaying calculated values, and take some time to return their values, so that's why we are doing it on a seperate thread.
[Code]...
I'm using a similar snippet of code for any control properties that have to be updated, and all work fine. On the above code when the actual Invoke is called, it APPEARS that the thread just ends and never calls the delegate, and doesn't return to finish either.
I have an annoying bug which is very difficult to replicate. When I start my application, from time to time, I get this error message "Invoke or BeginInvoke cannot be called on a control until the window handle has been created". This makes the user think the application is unstable... I have no idea what could cause this problem. The application uses a splash screen. It's built in Visual Basic using VS 2010 and .net framework 4.
View 1 Replies