I want to use the following snippit.
For Each x As Control In Me.Controls
If TypeOf x Is CustomControl Then
SomeAction( x.CustomEventofCustomControl)
End If
Next
The problem here is that not all controls have event CustomEventofCustomControl, so the complier shrieks. How do I get around this.
I have the following classes: Public Class Email
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If a create a wrong email lets say "email" the exception is correctly cached and a message is showed however is i input a valid email the event is not raised, the object is being created but no message is shown and no error or exception is thrown i suspect it has something to do with using "myemail = new Email(email)" but i have seen examples of using new with withevents with no problem.
I have a Child class which uses DataContractSerialization and raises a Changed event when its Name property is set.
<DataContract()>
Public Class Child
Public Event Changed()
The Parent class is serialzed and deserialized and all the data (including the Child) is saved and resored as expected.However, after deserialization, the Changed event is never raised!I know the deserialization process bypasses class constructors, but shouldn't the event be initialized?Is it possible to serialize/deserialize the Event?Is there a way to initialize the event in the OnDeserialzed method of the Child rather than the Parent (see below)?
(1) Add a constructor to the Child class which takes an instance of itself as an argument.
(2) Add an OnDeserialized method to the Parent class which creates a New instance of the Child class based on the deserialzed instance of the Child class.
<OnDeserialized()>
Private Sub OnDeserializedMethod(ByVal Context As StreamingContext)
Child = New Child(Child)
End Sub
Now the Changed event is raised as expected.
I am working on a project which will be installed in Embedded pc which won't have mouse and keyboard. Works with touch screen. I have an option in my software to make calls.I need to have an option like Push to talk. When need to talk they need to push the button and when they release they can't talk. Something like walkie talkie concept. The embedded pc where my software will be installed will have touch screen. How can I do this??
I tried to write my code in button click event and when they take out the mouse from the button, I am stopping voice. But, that is not I want. I need to push to talk and release after talk.
I'm converting a VB project to C#, and I notice that in vb it will call a function like:[code]on the asp.net source page or it will never hit the function. Is this a necessity in c#, or is there something that I'm overlooking or missing? Basically, is there a way in c# for it to hit that function like in VB without adding the line above in the source page?
View 2 RepliesI have combobox and I was wondering how do I call one of its events, for example,MyComboBox5_SelectedIndexChanged. I have no idea what to put in for its sender and e arguments.In other words; how do I complete the following statement
View 4 RepliesI have created a form in a project with some controls on it and put code behind those controls so they all work as I want them to. I now decide I want to group those controls within, say, a Groupbox to visually isolate them from the rest of the form.
So I select all the controls, delete them, create the new Groupbox, paste the deleted controls back and all looks OK. However, all the controls have now become "detached" from their associated events. The events still exist in code and the controls still retain all their properties but the controls no longer function.
Is there a way to "refresh" the project so that the controls are re-attached to their events or do I have to go through each control and do it manually?
I believe I may have already posted a much longer explanation of this , but its driving me spare!!! I have several pieces of code that click buttons thru sendmessage commands, all the code works fine in Windows 7! But I put the app on WindowsXP and only some of the buttons will work,
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I'm developing a website in visual studio 2008 using (asp.net/vb)I have to allow registered users to build pages and add controls that are already defined by the same userMy problem is how to build this page dynamically?In other words, I'd like to make like any CMS (e.g. Joomla). CMSs allow us to make new pages and add our controls then save them..
View 1 RepliesHow to define handler events for dynamic controls.
View 3 RepliesI have a form with 2 contols that I with to connect by drawing a "wire" on the screen. It goes like this: you mouse down on the first control then move the mouse while holding the mouse button down. When the mouse is over the 2nd control the mouse button is released and the controls are wired.
So I am playing with mouseup, down, move, etc. When the mouse is over the first control I get mouse moves from that control, but when it moves off the events stop, and I get no events from the form even though the mouse is there.
Is there a way to do this? I have seen it done in a Java app. I could brute force it and just draw a box on the form instead of a control, but that sounds like a step back.
Handling Events For An Array Of Controls
View 3 RepliesI made a custom control for my form. It's basically a custom button I made using a label.The only problem is, when I apply a myButton_Click event to the control in my main form, it will only be triggered if the control itself is clicked. The label takes up the entire form (it's docked inside it). The click event isn't triggered when the control (virtually the label) is clicked. You must click behind the label (the form's background) for the event to be triggered. How can I pass the myButton_Click event to the label so it is triggered when the label is clicked? I hope I'm making sense.
View 9 RepliesIm curently writing an app for windows mobile (so its using the compact .net framework)It has a loop which finds out how many images are in a folder, makes a picturebox for each one, then sets the .image property to the appropriate image. It also adds the name, size, location etc.What I dont know how to do is add a mouseclick event to it?I probably would have a subroutine already written in the code which could be used, or would it have to be a new one made for each picturebox?
View 1 RepliesI have this issue where I'm trying to generate HTML to display on the page that is coming from the database in form of a template that has different curly brackets that get replaced with dynamic content at run time. For example curly bracket {Content} gets replaced with a few checkboxlists, radiobuttonlists, textboxes and a submit button. The way I'm doing this is by creating controls dynamically and rendering them as string and then outputting that string to the browser. But what this does is, it doesn't recognise the events assigned to the controls when they are generated. I may be taking a wrong approach to the issue, but I don't really see how else this can be achieved. I have put up some sample code below to show what I'm trying to achieve.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
[Code]....
I have a number of user control dynamically added to a page, and user interaction with these dynamically added user controls need to be handled by the control's parent. Is this what is referred to as "event bubbling"?How do I do that in VB?
View 3 RepliesI've a control that throws an exception in one of its events and I need to catch this exception. How can I do this?
Example:
Private Sub AxNtlxImage_Reason(ByVal sender As Object, ByVal e As AxNTLXIMAGELib._DNtlxImageEvents_ReasonEvent) Handles AxNtlxImage.Reason
' TODO: Deal with this reason message
Throw New ArgumentException(e.sText)
End Sub
I want to catch this exception from another procedure when it happens.
I like to build objects that contain properties and also functions / subs to do work. I dont have a lot of other programmers around me to answer this question so I thought id ask. If my goal is to make a function or even sub part of a class blue print is it better to do it by making a seperate class for the function, and then construct a new copy of the classFunction as a property of the parent class or is it better to simply put the function in the parent class.
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I had been searching as to how I could create an array of controls dynamically, and after some searching found some helpful code as shown below [code]This way in the above code "structureComboBoxes" will have an array of comboBoxes (VB6.0 was way easy to get this crap done!! I guess its cleaner here)Now my next problem is How do i code for events of each of these combo boxes?
View 6 RepliesI found this mystifying in VB6 and it's still here...
For example - I have a combobox on a form and I have put some code in its SelectedIndexChanged event. The problem is that I want this code to be executed *only* when the user clicks on an item in the combobox dropdown. Why is it then that it gets executed when the form first loads? And how do I stop this happening?
I used to use a "FormLoading" boolean to decide whether or not the code was executed but this surely shouldn't be necessary. Is there a better way?
Here is a simple class I coded inheriting SimpleShape in VBPower Packs. The events are not firing. What might be the reason? I checked the property "CanRaiseEvents" and it says "True"
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I have VB 2008 Express and I am also new to VB. My problem is I cannot find any assistance with creating an Event that is attached to a Control that I inserted on a dynamically creeated TabPage. I call the "create_tab" sub (below) that creates a New TabPage and add some Controls (Button, two textboxes). Now, that I have the TabPage (and there could be multiple), I want to bind an Event to these items. So when a user Clicks on the Button in TabPage1, for example, a Sub executes where I can manipulate the data contents of the textboxes. Here's My code that creates the tabpages dynamically.
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I have created a simple custom control - we will call it a "panel with buttons". Here is how I instantiate it:
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So what I wind up with are multiple instances of my panel. Each of these panels has a button on it called Button1.
My question is - how do I capture this button event in a way that I will know which panel index it came from?
In the custom control there is only the Button1_click event - and when I click on it in any of the multiple panels I manually instantiated the event does occur, but how I can tell which one of my instantiated buttons were clicked...
Let's say I cut a tab control with buttons on it and paste it into a Panel control. After doing this, all my control events are being unlinked from the event code. I have to manually relink all the events in the Properties window. Is there any way round this?
View 15 RepliesI am trying to make a small control that has a picturebox and a few labels that can be dragged on the form it is placed on. The control was easy, and I can drag it fine when the mouse is down on the control, where there are no other controls, like not over the picturebox or labels.
When i try to click and drag the user-control and the mouse is on the picture box or labels of the control the mouse down event is not detected. I am hoping someone can tell me how to pass the mouse-down event from the controls on the user-control so the form I place it on detects the mouse down even no matter where on the control i click.
I am trying to use the keydown/keyup events with buttons in the same project and it not working properly. I have 4 red boxes and when I press an arrow key the box should change to green according to which arrow key it corrosponds to. I have this part working fine, however only when there is nothing else in the project. When I add in say 3 buttons, Button1, Button2, Button3 and try runing the program instead of the correct red box changing to green, button outline just moves between buttons 1,2 and 3. I have tried turning tabstop off for the three buttons but that didnt work. how to read the keydown/keyup while still having buttions that can be pressed with a mouse?
View 4 RepliesPublic Class aaMyForm
Inherits Windows.Forms.Form
Added some controls. Build it, add the .DLL as reference to my other project.
In my other project:
Imports MyLib
Public Class XForm
Inherits aaMyForm
The events from aaMyForm execute correctly but the controls added to it are not shown on XForm. I have found some info about set Modifiers Protected in order to be able to change the functionality of the controls but havent found anything about why the controls aren display on the XForm.
I have a listbox of items that need to be processed, and I would like to process them asynchronously on a separate thread. (Never done this before).So I created a Delegate, a Callback, called the method that does the work on the listbox items.
I am getting an exception "System.InvalidOperationException": Cross-thread operation not valid: Control 'ListBoxBlah' accessed from a thread other than the thread it was created on.
Doing the asynchronous operation for individual items doesn't make sense to me because I am only doing it to perhaps perform a large number of operations (the listbox may have 20000 items) in the background while allowing the user to do other stuff.
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In my project i have moving picturebox array & if they intersect treeview will disable.& when i rightclick on the picturebox it will delete.After deleting picturebox its effects still there.When other picturebox moving on that deleted area still treeview is disabled.i used this code.
Me.Controls.Remove(a)
where a= new picturebox
I often see code snippets for handling each control of a certain type on a form or panel, etc.They always start with For Each ctrl and the do a test for control type.Many .NET users are not aware, as I was not until I tried it recently, that we can LINQ on the controls collection.Below is a simple sub I created for resetting every checkbox on a panel I use as a validator.
Private Sub ResetCheckBoxes(ByRef pnl As Panel)
Dim ctrls as System.Collections.Generic.IEnumerable(Of Object)
ctrls = From c In pnl.Controls Where TypeOf (c) Is CheckBox
[code]....