arrays and structures

[Salat]

I've made those structures

   Public Structure typeObiektStrony
       Dim Left As Integer
       Dim Top As Integer
       Dim Width As Integer
       Dim Height As Integer
       Dim Value As String
       Dim Text As String
       Dim ToolTipText As String
   End Structure
   Public Structure typeStrony
       Dim BackGround As Image
       Dim BakcColor As Color
       Dim Width As Integer
       Dim Height As Integer
       Dim Obiekty() As typeObiektStrony
   End Structure
   Dim dc As typeStrony

 

when I try to get dc.Obiekty(i).Left the 'System.NullReferenceException' appears. It's probably beacous the number of elements in obiekty array is not specified. I realy don't know how to do this.

 

I've searched the forum, msdn and help files... please help me...

[Nerseus]

You need to redim the array Obiekty. I'm not sure if the ReDimming part is right - someone can correct me later :)

 

   'Snipped the structs definitions...
   Dim dc As typeStrony

   ReDim dc.Obiekty(1)
   dc.Obiekty(0).Left = 14
   
   'The following will fail because Obiekty is only defined to have one element, (0)
   dc.Obiekty(1).Left = 14

 

-Nerseus

[Salat]

I supose: When You are trying to use array in array then

redim dc.Obiekty(20)
redim dc.Obiekty(0).CosTam(20)
redim dc.Obiekty(1).CosTam(20)
redim dc.Obiekty(2).CosTam(20)
...
redim dc.Obiekty(20).CosTam(20)

writing just

redim dc.Obiekty(20).CosTam(20)

won't be enoguht to create array with 21 Obiekty and 21 CosTam in it. Am I right?

 

And the last question: When I use ReDim in Load event then whole Module will 'know' that there are 21 Obietkty in this array. Right?

[Iceplug]

Yes, you have to Redim each dynamic array that you have... you could do it in a loop:

Dim LV As Integer
Redim dc.Obiekty(20)
For LV = 0 To 20
 Redim dc.Obiekty(LV).CosTam(20)
Next

And the last question: When I use ReDim in Load event

That depends on where you have declared the original Dim... if you declared it in your main module general area, then the whole module will know, but if you define it in the Load event, then only the Load event will know... but the ReDim can be anywhere... preferably before you start operating with the arrays. :)