Reference A Form From A Variable?
Nov 24, 2009
I am upgrading a very large project from VB6 to VS2008. I have several forms with dozens of combo boxes on each form. I use the same combo box names for each form and want to fill them from a module with different items depending upon the calling form. In VB6, I dimensioned a public variable - FormName as object and called Set FormName = frmMyForm1 on Form Load. In a module, I was able to write the following code:
With FormName
.combobox1.additem("item")
.combobox2.additem("item"
End With
I cannot make this work in VB.Net. When the form loads I call FormName = Me. If I dimension Friend FormName as Object, I get the error message that Public member combobox1 on type MyForm1 not found. If you are attempting to access members on a late-bound object make sure it is declared public". If I dimension Friend FormName as Form, I get an error that says "combobox1 is not a member of System.Windows.Forms.Form".
I have tried both CType and DirectCast to convert the form variable from Object to Form with no success. I also tried creating a public array and storing each form name in it.
View 4 Replies
ADVERTISEMENT
Aug 18, 2010
I have an application consisting of 2 forms (Form1 and Form2).There is a text box on each form and they are both named Text1.From a sub routine in a module, I want to alter a text box on one of the forms. The sub determines which form to write to and attempts to refer to the form using a variable.But in the example below, gForm never gets declared when it's nested within the If statement.[code]The actual application is not so simple and I need to use this or a similar approach throughout the application in order to reduce code redundancy.To recap, I want to alter a control on a form by replacing the form name with a variable name. [code]
View 4 Replies
Feb 25, 2011
I have public variables in a module. I need to get the reference of the variable by using the String name of variable in another formell me how to do this?I need something like the following code:
Dim Var1 As string
Dim sVariableName As String = "Var1"
GetReference(sVariableName).SetValue = "testing"
[code].....
View 2 Replies
May 26, 2010
I pass this class i created a variable by reference and i want that reference to be assigned to m_Text so that when i change m_Text it changes the TextValue variable i passed. Example:
Dim test2 as String = "ok"
Dim test as New GeneTextBox(test2)
'then some one changes the text in the GeneTextBox and i want it to change the test2 string...
Public Class GeneTextBox
Inherits Windows.Forms.TextBox
Private m_Text As String
Public Sub New(ByRef TextValue As String)
[code]....
View 1 Replies
Feb 1, 2012
I have the following code passing a dataView variable to a function and I am getting the following warning:"Variable 'cl' is passed by reference before it has been assigned a value. A null reference exception could result at runtime."
Function Editclass()
Dim cl As DataView
Bindclass (SqlConnection2, cl)
[code].....
View 1 Replies
Feb 9, 2011
The code below works for the class that I hard coded "XCCustomers" in my RetrieveIDandName method where I use CType. However, I would like to be able to pass in various classes and property names to get the integer and string LIST returned. For example, in my code below, I would like to also pass in "XCEmployees" to my RetrieveIDandName method. I feel so close... I was hoping someone knew how to use CType where I can pass in the class name as a string variable.
Note, all the other examples I have seen and tried fail because we are using Option Strict On which disallows late binding. That is why I need to use CType.I also studied the "Activator.CreateInstance" code examples to try to get the class reference instance by string name but I was unable to get CType to work with that.When I use obj.GetType.Name or obj.GetType.FullName in place of the "XCCustomers" in CType(obj, XCCustomers)(i)I get the error "Type 'obj.GetType.Name' is not defined" or "Type 'obj.GetType.FullName' is not defined"
'+++++++++++++++++++++++++++++++
Imports DataLaasXC.Business
Imports DataLaasXC.Utilities
[code]....
View 2 Replies
Oct 28, 2011
I am working on a little program (game) is called Pig latin. I created a sub procedure and I passed the word to be converted by value and the piglatin word byref.Now when I call the procedure in the button click event I get the wavy green line under the variable passed by reference but the program works ok. Call Convert_to_Pig_Latin(strOriginalWord, trPigLatinThe error message when I hover my mouse over the green line says " Variable strPigLatin' is passed by reference before it has been assigned a value. A null reference exception could result at runtime."
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code].....
View 4 Replies
Dec 25, 2011
Class1:
Dim v as integer
public sub storeVar(byval s as integer)
v = s
end sub
[code].....
I need to save a reference of variable s in Class2 in variable v in Class1.(i.e. when the value of s changes v also changes (and vice versa)Is this possible since vb.net doesn't have pointers?Will it work if I change "byval" to "byref"?
View 1 Replies
Jun 30, 2010
Such as:
mylist.FindAll(Function(item) item.property = variable)
The reason I ask is if I use syntax like this, I tend to get a string to whatevever conversion error, which makes me think "variable" is being treated literally as a string.
View 1 Replies
Apr 5, 2011
I have a class that I would like to link at construction to a given control (say a textbox)
I know I can put a variable into a subroutine referentially but is there a way to store it in the same capacity?
View 1 Replies
Jul 16, 2009
[code]...
In the above code i have created a reference to class B from class A. The reference variable "refB" created as a attribute. But i need to encapsulate this reference variable in a property also i need to ensure than instantiation reB = New B() is done even after the use of properties.
1. How do i encapsulate the class reference variable "refB" in property?2. If i hide this class variable "refB" in a property, how do i write the code code initilize "refB" in "A"'s constructor?
View 4 Replies
Oct 20, 2009
passing a variable to a sub procedure by reference. Not sure I understand how it works. Here is the code.
Private Sub bntcompute_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bntcompute.Click
Dim x, y As Double
getnumbers(x, y)
displaysum(x, y)
[code]....
Is the newly modified variable actually being Passed back? and If so where in the statement is it passed back. is it being passed back to the call getnumbers or is it passed back to the statement displaysum?
View 6 Replies
May 7, 2012
I have many textboxes that I need to reference dymanically. The controls themselves aren't dynamic, just the way I need to reference them.I've got several text boxes say:
txtMe1
txtMe2
txtMe3
...
txtMe100
I will need to randomly change one of the properties of the edit boxes. So lets say it picks a random number between 1-100 which is 56. So, I would want to change the background of my 56th edit box to:
txtMe56.Backcolour = Color.Gray
The only way I could think of doing this would be to have one giant select case statement to evaluate the random number. But, that is really dirty and not the best peformance wise (this could potentially get called hundreds of times) so was wondering what my options are?I tried to concatenate the random number to my generic control name 'txtMe' but it throws a wobbler. I essentially would want the following to worK:
dim iNum as integer = 56
txtMe & iNum & .Backcolour = Color.Gray
View 2 Replies
May 14, 2009
I have a third party dll. I wish to create a variable to reference to one of the variable in it.so that the value in the class change, my value also change. The senario can be reproduce from the code below.For the code below i wish to get the form to display 2 instead of 1. How can i make my variable test2 always referencing test.testValue?
View 11 Replies
Sep 15, 2009
is this safe (I know it works, but is it safe)? Is it returning a reference to a local variable, wich falls out of scope as soon as the function returns?
Public
Function myfunc() As String
Dim strXml As String
[code]....
View 9 Replies
Jul 7, 2008
Im getting the Variable (Data) is passed by reference before it has been assigned a value error.
[Code].....
View 3 Replies
Oct 4, 2009
I'm trying to combine some text and a string value to reference a variable name.[code]
View 4 Replies
Mar 16, 2010
Is it possible to make a variable hold a reference to an integer instead of copying its value when using integerVariable = integerValue ?
View 2 Replies
Mar 14, 2009
In 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 Replies
May 27, 2009
I'm building SQL statements with a bunch of values from a dataset. Obviously that gives some really long names to put inline or even in parameter. addwithvalue code so beforehand I just declare a bunch of variables with really short names and assign them to the DS's exact fields like: [code] but this way I'm putting all the data in the dataset into memory twice by copying it into a new variable, right? So I was thinking, if it's just a string variable representing a field on the dataset, why not declare it by reference so the variable is basically a handy nickname pointing to that field in the dataset.Will it even work to have a string declared by reference and connected to one value inside of a dataset? And if so, will that stop duplicating everything in memory? I forgot how to declare a variable as a reference to another variable instead of the normal way in VB.
View 12 Replies
Jan 31, 2012
How do I reference txtCourse1.text and txtDept1.text using an index variable similar to to code below which does not work?
'two controls on the form
txtCourse1.text
txtDept1.Text
[code].....
View 2 Replies
Nov 17, 2010
How does the GC dispose objects created in the following 2 scenarios?
1)
Private Function DoSomething() As Boolean
Return New DatabaseManager().Insert()
End Function
2)
Private Function DoSomething() As Boolean
Dim mngr As New DatabaseManager()
Return mngr.Insert()
End Function
In Option 1, I don't create local variable to hold the reference of the object. In Option 2, I hold the reference in local variable.What option is better and why? (if any)
View 2 Replies
Mar 20, 2009
, I was wondering if it was possible to reference a member of a structure by using a string variable. Here's an example of what i'm talking about:
[Code]....
Now, I know that you would usually reference the value in any of the members by using the following (String1 in this case)
[Code]....
View 4 Replies
Mar 13, 2010
I've been trying implement Constructor method in passing variable between two forms.Just a rough user interface guide - issue Invoice. User would type in all the Customer Name, Document Number. Once he reached Item Details, a Child Form would pop-up for the User to select/search the Invoice's Item; Once selected, the selected item would showed in the primary Form.
What I had tried is, the Constructor method worked perfectly when it is self-contain in a new project, yet to be implement in my application.But when I implemented, there is an error: Reference to a non-shared member requires an object reference.
[Code]...
View 6 Replies
Sep 5, 2010
Using Visual Basic 2008 Express. I need to pass a variable to another form. Or else make the variable visible to both forms.
View 4 Replies
Jun 12, 2011
Variable 'loNode' is used before it has been assigned a value. A null reference exception could result at runtime.
why I am getting this error?
Imports System.Xml
Module Module1
Sub Main()
Dim doc As New XmlDocument
[code].....
View 2 Replies
Jan 28, 2012
My app has a main form (it's the startup form). It includes a number of menu items which typically open modal sub forms. However there are 2 menu items which just need to open an Outlook Explorer calendar for the user to manipulate appointments. My VB6 version used hidden sub forms to do this and handle the subsequent interaction between the user and the Outlook objects in the Calendar. I need to stop the user interacting with the main form while the Outlook Explorer is open, ie as if the Explorer window were a modal sub-form to the main form. So I manually disable the main form while the Outlook activity is going on, then (try to) enable it when the user closes the Outlook Explorer window. Problem is I can't seem to get a reference to the main form from the sub form to do this, nor pick up an event in the main form which I could use to trigger the enabling of the main form.An alternative might be to delete the hidden sub forms & put all the code in the main form, but this would be quite ugly; I think I would need to maintain two parallel sets of Outlook objects at the top level in the main form for each of the two functions (a number of the Outlook objects are declared With Events). I would have to have for example mobjOutlookExplorerFunction1 and mobjOutlookExplorerFunction2.
View 5 Replies
Jan 12, 2011
In the Session_Start of the Global.asax i have
Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)
Session("login") = False
[code]....
Why i am getting error the error Object reference not set to an instance of an object. at line
If Current.Session("login") Is Nothing Then
while checking for the login state as follows?
If GetLogin = False Then
'Do something
End if
I mean i have already created the instance on the Session_Start... Haven't i?
View 1 Replies
Jun 10, 2011
I have one form, which the user enters upto 5 websites then clicks go - I have on the second form, the one with the webbrowser. timer which checks if the web browser is busy then either a green light or black image will be shown along side the assocaited input box on the first form. I am finding it impossible to feed variables into the clock through ByVal, like I would a subroutine or function.
[Code]...
View 4 Replies
Dec 14, 2010
I am working on an application that is a form, at runtime it connects to a server and downloads an xml file, this xml file is used to build the actual UI which consists of various panels that are populated with textboxes, buttons, etc. On each panel there is a custom button that when clicked fires an event inside the actual custom button class that runs a sub on the form to hide all the panels and then show the panel who's name is held in an extra property(hence the custom button).
What I would like to know is what is the best way to give the button a reference to the form to run the showPanel sub. Is it best to give it the name of the form, or in the constructor for the button give it a reference to the form using byRef or byVal, or use the sender in the button click event as:
Private Sub newButton_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Click
sender.TopLevelControl.showPanel(m_showPanel)
End Sub
View 3 Replies
