I have some code to create dynamic serial port objects, now Im trying to add an event handler to the object so I can capture the dataReceived event. But the vb designer is saying ".datareceived" is not en event of 'object' in this case serialports(dComPortNum)
Public serialports(5) As Object
dComPortNum=1
serialports(dComPortNum) = New SerialPort
[code]....
We are migrating an application from C# to VB to meet our project's needs but stumbled upon a problem with event handling in VB.
The application uses a COM Wrapper access a scanner in Silverlight. The object is created dynamically in the code, and an event is added to "AcquirePage". This requires elevated trust of course.
Code in C#:
dynamic TwainSession;
(...)
TwainSession.AcquirePage += new AcquirePageDelegate(AcquirePageEventHandler);
As the only real "equivalent" of dynamic in VB is Object, we use:
Private TwainSession As Object
Everything is fine up to the point we want to handle an event of this Object. Because we are in Silverlight, we cannot have knowledge of the Object's structure or events, hence the need to create it dynamically. In C# we simply use "+=" to add a handler to an event but:
AddHandler TwainSession.AcquirePage, AddressOf AcquirePageEventHandler
In VB gives: 'AcquirePage' is not an event of 'Object'
I am fairly new to VisualBasic .NET (2008). I'm creating an application that, when a number is entered into the textbox, a new form window is created and populated with buttons. Each button starts the same command, but with a different parameter (the parameter being the pertinent record number found by the search).'The records are asset tag numbers.The procedure works fine if there is only one result.But the search allows for partial numbers and that's where the trouble begins.If two or more results are found, each button is configured with the last number found. The button being clicked doesn't tally with the proper ID number.[code]
What I didn't count on was that the event is only called when a button is clicked. When buttons are made, they are not assigned at that time.I've had problems trying to carry over the (current value) for pcArray(i), hence having it populate that form3_text field. When trying to add in a second object to be passed, I get the following error:"Method prtivate sub DynamicClick(sender as object, pcNameInfo as object, e as system.eventargs) does not have a signature compatible with delegate sub event handler with delegate 'delegate sub eventhandler(sender as object e as system.eventargs)."I tried manually entering a "Delegate sub eventhander" with the pcNameInfo object and VB 2008 ignores it.What can I do to get each newly made button to be told to run the RemoteIn(pcArray(i)) process properly?
I have a number of UserControls that have the same event .
When I use an Object instead of UserControl, I can not use Addhandler.
Here is the simplest example of my problem: In this example error is "TextChanged is not an event of Object"
Dim obj As Object = TextBox1 AddHandler obj.TextChanged, AddressOf text_changed_event I have to use this structure, because in a FOR loop I use some different UserControls as obj. All UserControls have the same event.
Is there a way to use this structure without error?
Maybe there is a way to define a new object that covers all my UserControls.
I have a number of UserControls that have the same event .When I use an Object instead of UserControl, I can not use Addhandler.Here is the simplest example of my problem:In this example error is "TextChanged is not an event of Object"
Dim obj As Object = TextBox1
AddHandler obj.TextChanged, AddressOf text_changed_event
I have to use this structure, because in a FOR loop I use some different UserControls as
[code]....
The addhandler function works this way: AddHandler Button1.Clicked, AddressOf Button1_Clicked, However, I have an unknown object: Dim o as Object, But I can't add handler for this object AddHandler o.SomeEvent, AddressOf SomeFunction, How do I add handler for unknown objects as stated above?
View 2 RepliesI have an ASP.NET page with code-behind in VB.NET. On the ASPX page I have a Repeater with an asp:ImageButton inside the repeater and I want to catch the clicks on the button. As far as I read I have to use FindControl and then handle the copy of the original control:
[Code]...
I read from a text file to see what I need to add to my MenuStrip. Each line in the text file is a new item. When I read I add the new item's OnClick event using AddHandler to get its text when it's clicked. Here are my two subs[code]....
View 6 RepliesI am trying to get the hang of Dynamic loading of objects from assemblies on the same machine (But NOT part of the same project).In the sample below, Form1 implements an interface built as part of the .dll I placed in C:Release. I am trying to create a local instance of Form1, and Cast it as Iform, so that the local code can access the properties and methods exposed by the interface.The assumption here is that at runtime, local code will have access to the String name of a form, and an interface which is implemented by the form (and is compiled into the .dll as well as the client application), and that is it.
When I run this code, I get a exception: "Unable to cast object of type 'WindowsApplication1.Form1' to type 'WindowsApplication1.Iform'.
Public Function fApplicationObject() As Iform
Dim sLocation As String = "C:ReleaseWindowsApplication1.dll"
Dim sType As String = "WindowsApplication1.Form1"
[code]....
I seem unable to dynamically load an object from a dll and then utilize an interface to access it's properties and such.
I have the following code to create an array of serial ports.
[Code]...
I want to build a MVC helper function for which I pass a Entity Framework object and have it build a select. Generally speaking I tried something like this:
Public Function RenderSelect(ByVal helper As HtmlHelper, ByVal sSelectName As String, ByVal aItmes As Array, Optional ByVal sTitleKeyName As String = "name", Optional ByVal sValueKeyName As String = "id") As String
' open select
[Code].....
However, it isn't working. It would be great to have a way to do this and pass the current entity object.
Dynamic Object Properties in a MVC Helper on a Entity Framework object
View 1 RepliesThe below code snippet works well for making ALL the text entered into a row is entered in upper case. However I only want to force the upper case on the last column. I was thinking I could put a If Then before the It TypeOf to determine if I was in column 3 (and exit the sub if not) but I couldn't get the syntax right.
VB
' Begin Code Insert
Private Sub dgvEntryPeople_EditingControlShowing( _
[Code]....
Not sure what to call this, but I have a number of dataseries that are being updated through an API connection. My form has charts that shall display the data, and I want the charts to subscribe to the update events raised by each data series. So I need the form class (or one of its member objects) to send a request to the BLL. But I don't want it to dig into the tree structure of my BLL by get to the desired data series. So.. I guess I must either send my chart object as just a "type Object" down to the BLL, to add the handler.. Or, I must request an anonymous object of the dataseries event to be sent to the form class? Am I on to something here? What to prefer? And how do I actually do this stuff?
Also it's a question what to add the handler to? I try to refactor my code as much as possible, so I try to make type of "Manager objects", like for example instead of adding chart object directly in my form class, I make a ChartManager class that the main form has a single object instance of. Then this manager has a list of chart objects etc.. This is like a UI logic layer, and will take a reference to the mainBLL object instance from the Main form class. I guess it's proper to add the handler directly to the low level ZgChart object...
[Code]...
I have progressbar controls added at runtime and I used AddHandler to assign a function to handle a click event on any of them. All is fine, but when I am coding in that function using sender, autocomplete (intellisense?) doesn't show the available properties, methods, or whatever for that object. Yet, when I guess, my code is valid and works just fine.
I have been at this project all day and advanced searches here have been so very helpful. My project is a multiple progressbar timer app that talks to a remote MySQL database on a Linux CentOS LAMP server on my LAN. I can't even begin to relay how much I have gotten my head around today.
Perhaps surprisingly I haven't added an event handler programatically before and I'm having trouble getting my head around AddHandler.I am creating a series of DataGridView controls in a loop and want to subscribe to the CellFormatting event on each of them.The event handler signature is as follows;Private Sub ConfigureRows(ByVal sender As System.Object, yVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs)This works fine when I enter it in the visual editor properties box but I can't figure out how to give it the correct arguments using AddHandler.
View 2 RepliesI'm building an Expandable Groupbox control (source will be available in the codebank if I finish it), which is basically a groupbox with a [-] or [+] button to the left which allows the user to expand/contract it.
I've got it working pretty well, but now I want the user to be able to click the button in the designer to expand/contract the groupbox, rather than having to find the Expanded property in the property list every time. The ExpandableGroupbox control is just a UserControl with two panels (header and container), with an actual Button and a label for the text in the header panel. I know how to enable the user to click the button, even in the designer (this is done using WndMsg's and stuff, don't really understand that but it works!).
Now, there is one problem. When the button is clicked during design-time, the control is contracted (it's size changes), but the designer is not notified of this change. The selection rectangle remains as if the control size never changed, which is very confusing to the user. It only changes to the correct size after I select something else, and then select it again: At the moment, when the button is clicked it raises an event called Expand. I thought I could have my Designer class listen for that event, and refresh the selection service when it fires. I can get the control the designer is designing simply with the "Control" member.
Now here's the problem: Obviously I need to attach the Expand event using AddHandler, and I can see only one time to do that: in the constructor of the Designer.
So I tried it:
vb.net
Public Class ExpandableGroupboxDesigner
Inherits System.Windows.Forms.Design.ParentControlDesigner
Public Sub New()
[Code].....
1. Can you see any other way to listen for the event? There is no 'control initialized' event or something I can use where I can attach the event as far as I know.
2. How do I refresh the selection service in the first place??
I need to represent the following query using LINQ:
DECLARE @PurchasedInventoryItemID Int = 2
DECLARE @PurchasedInventorySectionID Int = 0
DECLARE @PurchasedInventoryItem_PurchasingCategoryID Int = 3
DECLARE @PurchasedInventorySection_PurchasingCategoryID Int = 0
[code]....
Now, I know that a query in .NET doesnt look like this, this is my test in the SQL Design Studio. Naturally VB.NET variables will be used in place of the SQL local variables.My problem is this: All of the conditions after "WHERE" are optional. In that a query might be made that uses one, some, all, or none of the conditions. V.PropertyID and V.Value can also appear any number of times.In VB.NET I can make this query easy enough by simply concatenating strings, and using a loop to append the "V.PropertyID/V.Value" conditions.I can also make a Stored Procedure in MS SQL, which is easy enough.However, I want to accomplish this using LINQ.
Ive managed to dynamically create a form, and dynamically create a timer, but i have not been able to create the timer on the dynamic form. Specifically, i need to be able to have the timer itself create another form with a timer. (I realize that this would create a new form every interval on the timer, that is what i want to do)
1. A way to add the timer to the dynamic form, and maintain the timer sub on my main form.
2. A way to create the whole thing over (dynamic form and timer) through the previous dynamic form and timer.
I was thinking i could use a collection/array to store the forms and timers, but i'm still having trouble figuring out how to add entire forms or timers into a list. (A timer is not considered a control, so i cant use a controlcollection...)
Heres my code;
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim frm As New Form
[Code]....
*EDIT* Btw, my idea was to use i as a variable that increases every time a form is created, then insert the form into the array, with i as the integer. i just need to know how to create a new form with a different name each time. (as with timers)
How to create an aspx page with a Flash object inside? And how to change the content of the Flash object?[code]...
View 1 RepliesSome people have argued that the C# 4.0 feature introduced with the dynamic keyword is the same as the "everything is an Object" feature of VB. However, any call on a dynamic variable will be translated into a delegate once and from then on, the delegate will be called. In VB, when using Object, no caching is applied and each call on a non-typed method involves a whole lot of under-the-hood reflection, sometimes totaling a whopping 400-fold performance penalty.
View 3 RepliesIs there any way to create an XmlSerializer that stores along with the serialized data the data type, then when deserializing, it automatically identifies the type of the serialized object and creates an object of that type (returned as object).
View 1 RepliesI currently have a XML file for an application I am developing. I have built a a XMLFile.GetContent function to read my XML File and load the content into a set of specific objects. These objects are then added to a collection and passed back to the main code to be loaded into the memory of the application.I am looking for a dynamic way of loading the information from the XML file into a specific Object Property. I have added comments to the function to show what I want to make dynamic.Content of XML File
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Config>
<IQSDataSources>[code].....
In a ASP.NET app from a procedure IN a VB code file a dynamic control is called. The first problem may solve the second. In the following line of code I am getting an "end of statement expected" error at the following line.
[Code]....
I have a PaintEventHandler connected to a picturebox via AddHandler.
In PaintEventHandler I have coded this for writing the drawing to PictureBox1.Image:
Dim PictureBox1 As PictureBox = CType(sender, PictureBox)
PictureBox1.Image = New Bitmap(PictureBox1.Width, PictureBox1.Height)
Dim bmp As Image = PictureBox1.Image
Dim g As Graphics = Graphics.FromImage(bmp)
... drawing something ...
PictureBox1.Image = bmp
Everything works fine but after running through the paint event handler and showing the picture on the screen it calls the painthandler again and again. It does not stop.
Replacing the code above with
Dim g As Graphics = e.Graphics
Makes it running. But then I cant save the Image to a file.
Anyone can suggest what's wrong to the code below as the User Control objects ONLY appear in the first tab and NOT in the balance tabs ?
1) User Control name - usRFQDetail
2) Tab Control name - tcRFQDetail
what's wrong to the code below as the User Control objects ONLY appear in the first tab and NOT in the balance tabs ?
1) User Control name - usRFQDetail
2) Tab Control name - tcRFQDetail
Dim tcPage As New TabPage
[code].....
The issue is when I try to add a new item to the ArrayList with the following code, it gives me an error:
vb Private Sub btnLabelAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLabelAdd.Click
Dim result As String = InputBox("New Filter Label:", "Label List")
[CODE]................
Object reference not set to an instance of an object.
I'm not really sure what I'm supposed to be doing with this. It's a new setting I just added and it's empty, so I'm not sure if that has anything to do with it or not. Anyone know what's going on and what needs to be done to get it to accept a value and not want to be "initialized"?
I have recently gotten my hands on a free, open-source IMAP connection API.So far, I have been successful in creating a connection to one of my accounts.Where I'm getting stuck is retrieving folders and/or emails from those folders.Does there happen to be anyone here that is familiar with this API, or even Gmail (particularly the folder structure for IMAP)?
If not, here is a link to the DLL that is listed on sourceforge and the company's website that created it (if you feel like testing):
Koolwired
Sourceforge - Koolwired API
I have created a test account so feel free to use the code below without worrying about username/password issues; I'll just delete it when I'm done with it.Here is the code I have made so far for making a connection:
Dim gSession As New Koolwired.Imap.ImapConnect("imap.gmail.com", 993, True)
Dim gAuthenticate As New Koolwired.Imap.ImapAuthenticate(gSession, "imap_test@serysoft.com", "imap_test")
Try
[code]....
When I run that code, I get an error that states:System.NullReferenceException: Object reference not sent to an instance of an object. (The bold line in the above code).
Now, I'm not sure exactly what that means. Does that mean it tried to access the server and "INBOX" doesn't exist so it gets returned a NULL value? Or is it possibly the coding itself?Maybe the Gmail folder system is weird due to the fact they use labels (even though from what I have read online, the labels act as the folders in the IMAP system).
i have created a dynamic tabpage and a dynamic tablelayoutpanel inside it then added dynamic textboxes and labels inside the tablelayoutpanel...the thing is , i am having a problem on how to access the value of those textboxes and labels and add them as new columns in the new table(tagpage) in mysql database, i can already create the table in the database but i cant add the new columns in it. heres the code for accessing the values of the labels and textboxes
error: NullReferenceException was unhandled....Object variable or With block variable not set.
sql = "alter table " & tbl_selected(counter) & " add " & frmMain.Controls("TLP_" & SecArrList_sp(counter2)).controls.item(SecArrList_sp(counter2) & "label" & counter).Text & " varchar(100) NULL;"