suma a doua numere in vb 6

Eu sunt incepator in visual basic 6.
am inceput prin a face programe simple ca sa imi dau seama de limbajul vb.
am o problema :
se dau 2 numere a si b .sa se calculeze a+b,a-b,a*b,a/b;
am creeat aplicatia astfel:

Dim a, b, c As Integer
------------------------------------------
Private Sub Command1_Click()
c = a + b
Label5 = c
End Sub
------------------------------------------
Private Sub Command2_Click()
c = a * b
Label6 = c
End Sub
--------------------------------------------
Private Sub Command3_Click()
c = a - b
Label7 = c
End Sub
-------------------------------------
Private Sub Command4_Click()
c = a / b
Label8 = c
End Sub
----------------------------------
Private Sub Command5_Click()
End
End Sub
-------------------------------------
Private Sub Text1_Change()
a = Text1
End Sub
---------------------------------------
Private Sub Text2_Change()
b = Text2
End Sub
---------------------------------------
Private Sub Text3_Change()
a = Text3
End Sub
-------------------------------------
Private Sub Text4_Change()
b = Text4
End Sub
-------------------------------------------
Private Sub Text5_Change()
a = Text5
End Sub
----------------------------------------
Private Sub Text6_Change()
b = Text6
End Sub
-----------------------------------------
Private Sub Text7_Change()
a = Text7
End Sub
-------------------------------------
Private Sub Text8_Change()
b = Text8
End Sub

aplicatia se compileaza , ruleaza toate, dar numai una nu merge a+b
exemplu:
daca a= 1, si b=3
atunci suma =13
de ce?
de ce nu-mi aduna valorile lui a si b?
astept raspuns.

Iti interpreteaza a si b-ul ca si stringuri, si atunci a + b = "1" & "3" = "13"
Declara-ti variabilele de tip Integer( e una din regulile de programare. pt ca devine mai clar codul si se evita astfel de erori ).
Cand citesti din TextBox, convertesti cu CInt( textbox.text ) in integer, si cand scrii in TextBox folosesti functia CStr.

shiva, on Jun 18 2007, 23:09, said:

ms.
acum merge . Am folosit functia  a= cint(text1.text)  si b=cint(text2.text)cum mi-ai spus si acum mi le citeste ca variabile integer.

shiva, on Jun 18 2007, 23:09, said:

Mai exact spus, ca valori Variant.

In definirea lor val_nec a scris:

Dim a, b, c As Integer

VB6 interpreteaza a si b ca find de tip nedefinit, prin urmare sunt de tipul implicit: variant.

Daca ar fi definit variabilele astfel:

Dim a As Integer, b As Integer, c As Integer

atunci codul ar fi functionat OK (fara concatenare, ci insumare).

Din fericire, in VB.NET aceasta problema nu exista. Toate cele trei variabile ar fi fost considerate Integer.