Question Is that possible to determine a variable name in run-time?

[pk028382]

I would like to declare some variables which their names are according to the textbox.Text. Is there any simple method to achieve my purpose?

 

[jmcilhinney]

You're not talking about variables. If you want to use String values provided by the user at run time then you would use a Dictionary where the keys are Strings. Let's say that you have two TextBoxes on your form: one for the key and one for the value. Your code might look like this:

Private ReadOnly valuesByKey As New Dictionary(Of String, String)

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    valuesByKey.Add(keyTextBox.Text, valueTextBox.Text)
End Sub

 

[pk028382]

You're not talking about variables. If you want to use String values provided by the user at run time then you would use a Dictionary where the keys are Strings. Let's say that you have two TextBoxes on your form: one for the key and one for the value. Your code might look like this:

Private ReadOnly valuesByKey As New Dictionary(Of String, String)

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    valuesByKey.Add(keyTextBox.Text, valueTextBox.Text)
End Sub

In fact, I want to do something like this

TextBox.Text = "abc"
Dim TextBox.Text as string

But that is an error code.

 

[jmcilhinney]

That's because it's not possible because it makes no sense to do so.

 

[inkedgfx]

you dont need to declare the textbox text....

InkedGFX

 

[AceInfinity]

I'm assuming you're doing this... If you have a pre-existing variable, lets say called "varA", and you want to type that into the TextBox, and retrieve the value of whatever varA is at runtime. Then the solution here is Reflection. And to understand the concept of Reflection, you'll have to know exactly where these variables are in the assembly. Are they in the main, usually called, Form1 class? Some predefined class? or elsewhere?

Perhaps it's in a Module? You'll need to provide more information on that.

But this much IS possible. The other way around, dynamically assigning variables in that way, no. It doesn't make any sense either. You'd have to recompile the assembly somehow.

 

[AceInfinity]

Example:

Public Module VariableContainer
    Public Const obj As String = "This is the value for variable obj, in the VariableContainer class..."
End Module

Dim obj As FieldInfo = Assembly.GetExecutingAssembly().GetTypes().First(Function(T) T.Name.Contains("VariableContainer")).GetFields().FirstOrDefault(Function(FI) FI.Name = TextBox1.Text)
If obj IsNot Nothing Then
    MessageBox.Show(obj.GetValue(Nothing).ToString)
End If

Now based on the above code, if the text in my TextBox was "obj", it would result as: