Create a control from a class

General
1

Ciao! I have a window with a canvas, first item of a set: mycanvas(0).
From an external class i want to create an other member of this canvas on my window.
If i do it from the window, all works fine but from my class i obtain an error. My code is:

[code]Dim c As New myform.mycanvas(0) ’ In the window i use only mycanvas

c.BackDrop = myimage
c.Height = 16
c.Width = 16
c.Left = 10
c.Top = 10
[/code]

How solve this problem?

2

Here’s a link to a good discussion about this. https://forum.xojo.com/34976-add-canvas-control-at-runtime/0

3

You should not point to one of the members.

This should work:

[code]Dim c As New mycanvas ’ In the window i use only mycanvas

c.BackDrop = myimage
c.Height = 16
c.Width = 16
c.Left = 10
c.Top = 10[/code]

4

Thanks, men! Michel, with your modification i obtain:

Can’t find a type with this name. Did you mean class myform.mycanvas?
Dim c As New mycanvas

Tanner, i tried to use the suggestions in the link but don’t works!!!

5

I want to create a canvas from an external class not from the same window.

6

From the piece of code you shared, it seemed you wanted to create a new myCanvas from a control set. I do not know any way to dynamically create a control that is not already instantiated.

You could place your myCanvas on a ContainerControl, and then, dynamically instantiate with embedwithin:
http://documentation.xojo.com/api/deprecated/containercontrol.html#containercontrol-embedwithin

7

Thank you, Michel, for your patience! Perhaps i lost some concept related to references.
I want to explain you only the essentials lines of my needs (my project is huge!).

I have a window with some textfields subclassed by a class (named textfieldCurrency) . In this class, i have an event, Open, where i want to create an istance of a canvas present in my window. The source canvas has a symbol of Euro as background and i want to create this effect:

From the same window of the source canvas it’s simple to do it:

[code]Dim c As New simboloValuta

c.height = 18
c.width = 18
c.left = prezzocli.left + 2
c.top = prezzocli.top + 2
[/code]

but from the textfieldCurrency class seems impossible!

8

prezzocli is my textfield and simboloValuta is my canvas with the Euro symbol.

9

You CANT create an instance of an object already created. You can add a property in textfieldCurrency of type canvas and pass the refference of the existing canvas on the open event.

But, a better way:

10

You’re right, Ivan, I said that badly! With my code (from the same window) i create only a member of the set of my canvas and that it’s simple! I’m not able to create a member from an external class!

Both your solutions are great! Thanks! I’ll try it now! Bye!!!