controls.add

If you get bored reading this, just skip it and read the bold part :D
I'm adding some controls to my form with the Controls.Add method, but the problem that I have is that I dont know how to write events for them:confused:
I am adding a whole buncha textboxes, I want them to act as control arrays but how can I tell my event what to handel?

here's an example of what I'm doing if I wasnt clear:

VB Code:

Dim txtValues(30) As TextBox
For i = 0 To 29
            txtValues(i).Size = New System.Drawing.Size(textWidth, textHeight)
            txtValues(i).Name = "txtValue" & i
Next
 
Me.Controls.AddRange(txtValues)

Now I want to add a sub so that if ANY of those textboxes are changed, I would be able to do something, just like a control array.
This is simple if I was doing it during design time, but since I'm adding the controls at runtime I dont know how to add the events for them:confused:

the bold part is my problem I guess :p

Look into AddHandler and RemoveHandler to add and remove event handlers at run time.

TNX!!! LOVE YA!!!!:) :)


eeh I think you can forget about the last part :p

I wrote this in C#, but it might help you. This a control that adds picture boxes to a panel control.

Code:

---

PictureBox pb = new PictureBox();
pb.Size = new System.Drawing.Size(iThumbSizeX, iThumbSizeY);
pb.BackColor = System.Drawing.Color.Black;

// Unique names for each thumb added.
pb.Name = iThumbCounter.ToString();
iThumbCounter++;

this.Controls.Add(pb);
Bitmap pic = new Bitmap(filename);
pb.Image = (Bitmap)pic.GetThumbnailImage(iThumbSizeX,iThumbSizeY,null,(IntPtr)0);

                               
// Subscribe to the newly created thumbs click event.
pb.Click += new System.EventHandler(this.pb_Click);

---

What I do is have one event that they all subscribe to. In that event, I take the passed in object and get the name. Since I named them numbers sequentially, it is easy to refer to them and use a basic select statement if I want.

:D:D:D:D:D
I cant figure this out, such a shame :p

VB Code:

Private Sub TextBoxValues_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
 
    End Sub

let's say this happens for a textbox, how can I say "textbox". text = something?

I'm adding the events with addhandler as you guys said:) but how can I access the textbox in that event?

The caller is passed in the sender object. Cast the sender object in a textbox variable, and you can use this variable.
eg:

VB Code:

Private Sub TextBoxValues_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
        Dim MyTextbox As TextBox
        MyTextbox = CType(sender, TextBox)
        MyTextbox.Text = "something"
    End Sub

But are you sure you want to change the text in the TextChanged event?

tnx alot :) works!
But I dont get it, why is it like this? Why is the textbox sent as an "object"? Cant we just change the type to TextBox?:rolleyes:

Oh and btw about the textbox.text, I was just trying to show an example of what I wanted to do:p I dont want to change the text in text_change ;) I'm writing a program to hold information about my CDs and it's suppose to add some textboxes dynamically to input data....
thanks for the help

oh well another question:p
let's say I want to access a texbox named txtValues & i and change one of it's properties. How can I do this?:confused:

You can loop through the controls to find one that has a name that matches.

Quote:

---

Originally posted by MrPolite
[BBut I dont get it, why is it like this? Why is the textbox sent as an "object"? Cant we just change the type to TextBox?:rolleyes:
[/B]

---

Most events use generic parameters. This way you can use the event handler for more then just textboxes. You could have one event handler handle events for textboxes, pictureboxes, etc.
You can't change the type to textbox, because the procedure definition wouldn't match the event definition for TextChanged anymore.

If you want to refer to a different textbox you also loaded at runtime, you can either loop through the controls collection of the form untill you find a control with the correct name, or use the variable you used when you loaded the textbox. I would recommend to declare the variable(s) at module level (possibly an array of type Textbox), so you can use these variables anytime you need them. You could either remember the index in this array (instead of the name), or set a property (eg. the Name property) , and loop through the array until you find it.

tnx alot guys :) that solved it :D