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].....
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
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 Repliescontrols mainly an indexed picturebox control. In VB 4, 5 and 6, I could make a picturebox(0) indexed, but in VB Express 2010 I no longer see this option in the picturebox properties window how is this accomplished in VB Express 2010.
[Code]...
How can to make control arrays in vb.net ? there is no INDEX property or Load method like VB6. so how i can do it ?
View 5 RepliesI have a few text boxes on my form (txt1, txt2, txt3...) and would like to assign values to them based on the index. I not sure how to describe but Something similiar to the following:
dim i as integer = 30
For n As Integer = 1 To i
[txt] & i.text = MyText" & i
Next
I'm trying to add a custom panel to my toolbox using a dll file, but when I add it as a reference it only appears as greyed out - and this is only after I click "Show All" in the toolbox.Everything builds fine in the Class Library project I used to create the custom control. Here is the simple
Imports System.Windows.Forms
Public Class pnDoubleBuffered
Inherits Windows.Forms.Panel
Public Sub New()
[code]....
I build the project, open my main project where I want to use the control. Then I click "Choose All" from the toolbox and add the reference using ".NET Frameworks Components". I find my dll file and click OK. Then nothing is added to the toolbox. I manage to see the control greyed out when I click the "Show All" option.
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]....
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].....
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]....
I've been looking everywhere for an answer to a simple question, but i'm having issues, so i thought i'd join and post here. I'm having issues with a simple concept. I load information from a SQL database, and i want to add a 'Passport' link URL relating to column cells called 'name'. It basically selects the name, and inserts it into the link fields to be opened. But i cant find a way to work it. I thought i could do it with something like:
[Code]...
I'm working on the exercise page 73 (VB 2010 in 24 hours). It's basically a form with 2 text boxes, 2 text labels and a command button. It's really simple and uses this loop to cycle through the items, and tell me the name of them in a Messagebox
[Code]...
The code is listed below which hopefully illustrates what I'm trying to do:[code]....
View 12 RepliesI am getting this error for Login.Show() here:
Imports Microsoft.VisualBasic.FileIO.FileSystem
Public Class Update
Public Sub CheckUpdate()
[code]....
I am also getting this is every other form when using the Login form, along with Login.Close(), and Login.Hide(). I haven't tested any other ones.
What is the correct way of assigning the selected index's value from a listbox to a variable? The user selects an item in a listbox and then the output changes depending on their selection.
I use:variablename = listbox.text
in the listBox_SelectedIndexChanged event and this works.
When I use the button_click event I use:
variablename = listbox.selectedindex
But this does not work in the listbox_selectedindexchanged event.you let me know if it is okay to use it like I did above or if I will run into problems and why you cannot use the selectedindex method.
I am trying to have the index value of a selected item in a combobox returned to a variable. Then, if the variable = 1 (which would be the index of th second item in the combobox), I want a groupbox to be hidden (be invisible) on the form. Here is my code...Getting an error that says:
'ListIndex' is not a member of 'System.Windows.Forms.ComboBox'
Code:
Private Sub cbxAccounts_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim selection As Integer = CInt(cbxAccounts.ListIndex)
If selection = 1 Then gbxCheck.Hide()
End Sub
I am trying to have the index value of a selected item in a combobox returned to a variable. Then, if the variable = 1 (which would be the index of th second item in the combobox), I want a groupbox to be hidden (be invisible) on the form. Here is my code...Getting an error that says:[code...]
View 1 RepliesI have a very large number of tables with data in the following format:
A X Y Z
1 0-2 0-13 0-1
2 3-5 14 2-4
3 6-9 15-16 5-10
In other words, there is a variable (call it A) with a single value that corresponds to a range of values in the other variables (call them X, Y, and Z).My program needs to accept user text input of values of X, Y, Z, etc. and then match each to the corresponding value of A.Example: User enters 4 in the X text box; program determines that if X=4, A=2.Again, we're talking about tables and tables of data in this format. Unaware of a better method, I have been using arrays.
Example:
Dim a() as double = {1,1,1,2,2,2,3,3,3,3...}
Dim x() as double = {0,1,2,3,4,5,6,7,8,9,10...}
Note how I had to artificially deal with variable A so that the index of each score corresponds to the index of the matching X variable.It is this modification of the variables that is taking forever. There has to be a better way! Hypothetically, what I need is the ability to do something like this:
Dim a() as double = {1,2,3,4...}
dim x() as double = {0 to 2, 3 to 5, 6 to 9...}
Is there a way to represent a range of values at a single index of an array, such as my hypothetical example above? This would save me hours of re-shaping the data to make the arrays work.
Dim tabnum As Integer = mycontrol.TabIndex
If My.Forms.Sessions.GroupBox1.Controls(tabnum).Enabled = True Then
mycontrol.ForeColor = Color.Red[code]....
I have checked and double checked the tab order on the controls and run traces with debug. The control found in my.forms. sessions. groupbox1 seldom returns the proper tab. Using a 'watch' I can see the tab names and the tabname (my.forms.sessions. groupbox1. controls (tabnum).name is often the incorrect one.
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.
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].....
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"?
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.
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?
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[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?
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?
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 Repliesis 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]....
Im getting the Variable (Data) is passed by reference before it has been assigned a value error.
[Code].....