CODEWITHSUNDEEP
.netvb.netloopsuser-interface
The_Neo
The_Neo

Reputation: 328

Visual Basic - Changing Button Color using a loop

For practice I am writing a VB application which simulates and elevator system with 4 elevators and 40 floors in the building - when a button is pressed I want it to change color until the elevator reaches that floor.

Currently the only way I can think of to do this is by hard-coding a check which looks through the list of destination floors that each lift has and if it contains a given floor change the color of that button like this:

' button 1
        If elevator1.goingUpList.Contains(1) Or elevator1.goingDownList.Contains(1) Then
            lift1Button1.BackColor = Color.LightGoldenrodYellow
        ElseIf (elevator1.goingUpList.Contains(1) = False) Or (elevator1.goingDownList.Contains(1) = False) Then
            lift1Button1.BackColor = DefaultBackColor
        End If

The problem is with this is that I would have to do it for each button (40 in total) of each of the 4 elevators - 160 times essential 960 lines to do a fairly simple task. THere must be an easier way?

I was thinking a loop that goes through the elevators lists , retrieving each floor that is in the list could be an easier solution - but how would I get the corresponding button to change color?

Upvotes: 0

Views: 3299

Answers (1)

Tun Zarni Kyaw
Tun Zarni Kyaw

Reputation: 2119

Yes you can use For Each loop for your buttons. Windows Forms have the Controls Collection property. Every control such as Button, Label and TextBox are added to that Contorls Collection unless you are using Panel, GroupBox or other containers.

By using For Each loop in Me.Controls, all type of controls will be going through. So you have to check for the type of control with TypeOf operator.

If your form has other buttons rather than "Elevator buttons", you need to set Tag property of your "Elevator buttons" to "1" or elevator number.

Here is the sample code

Dim ctl As Object
Dim elevatorNumber As String
Dim buttonNumber As String

For Each ctl In Me.Controls
    If TypeOf ctl Is Button Then
        elevatorNumber = ctl.Tag
        buttonNumber = ctl.Text

        If elevatorNumber = "1" Then
            If elevator1.goingUpList.Contains(buttonNumber) Or elevator1.goingDownList.Contains(buttonNumber) Then
                ctl.BackColor = Color.LightGoldenrodYellow
            ElseIf (elevator1.goingUpList.Contains(buttonNumber) = False) Or (elevator1.goingDownList.Contains(buttonNumber) = False) Then
                ctl.BackColor = DefaultBackColor
            End If
        End If

    End If
Next

Upvotes: 1

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