[RESOLVED] Color Change Question

I'm working on a program that requires an object to change colors each time a user clicks it.

The object I am trying to edit is a "Panel".
So, what I've done so far:

I've double clicked the panel, loading the code in the code window.
I set the declaration to "MouseClick", and added the following code:
Panel1.BackColor = Color.Blue

This works without a flaw - the program loads with the panel being the default color I chose.
Once clicked, the panel changes to blue - perfect.

The only problem is, I cant figure out how to add additional colors to the equation.

I've got about 15 colors I would like to use.
Each time the user clicks the panel, I would like it to move to the next color on the list.
When the last color is reached, I would like the list to start back over.

So, I'm not sure how to add multiple colors, and I'm not sure how to create the loop that will restart the set once the last color is reached.

Any help would be greatly appreciated!

The way that I would do it is to store those colors in a general list(of t) at the form load then declare an integer at the form level and increment it by one every time the panel is clicked:

Code:

---

Option Strict On
Option Explicit On
Public Class Form1
    Private color_list As New List(Of Color)
    Private int As Integer = 0

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        color_list.AddRange({Color.Blue, Color.Red, Color.Green, Color.Yellow, Color.Orange})
        Panel1.BackColor = color_list.Item(0)
    End Sub

    Private Sub Panel1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Panel1.Click
        If int < color_list.Count - 1 Then
            int += 1
        Else
            int = 0
        End If

        Panel1.BackColor = color_list.Item(int)
    End Sub
End Class

---

Thank you so much for your reply!

I'll give this a shot when I get home this evening.

Slight modification to previous post. I added the color from the designer and changed declaration of the idx into the color list.

Code:

---

    Private color_list As New List(Of Color)

    Private Sub Form1_Shown(sender As Object, e As System.EventArgs) Handles Me.Shown
        color_list.Add(Panel1.BackColor) 'add color from designer
        'add other colors
        color_list.AddRange({Color.Blue, Color.Red, Color.Green, Color.Yellow, Color.Orange})
    End Sub

    Private Sub Panel1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Panel1.Click
        Static idxCL As Integer = 0 'index into the color list
        idxCL += 1
        If idxCL >= color_list.Count Then
            idxCL = 0
        End If
        Panel1.BackColor = color_list.Item(idxCL)
    End Sub

---

dbasnett -

I greatly appreciate you taking the time to reply to my thread.

If you have a free minute, I'd love to know a bit more about the difference between your code and dday9's.
I can see that its a bit more light weight in terms of code - but im not really sure whats going on here...

I follow the first part - where you are creating a list of colors.
The loop is where it is getting a bit confusing for me.

I aplogize - Im new to vb, so the If Loop syntax is new to me.
(I've been trying to learn C++ as well, this looks similar to the C++ if loop, but the functions look a bit different).

I assume the "+=1" is the same as "++" in C++?

the "If idxCL >= color_list.Count Then idxCL = 0 End If...."
So, this is saying that if "idxCL" is greater than or eaqual to the number of colors in the list, that it will reset the variable to 0?
Which I assume is what sets the panel color back to its original state.

What I dont understand, is where we told the program that 0=orignal color.
Is this because it is the first item in our list?

Sorry in advance for the noob questions

Quote:

---

Originally Posted by codenewbie

dbasnett - ...I follow the first part - where you are creating a list of colors.
The loop is where it is getting a bit confusing for me....

I assume the "+=1" is the same as "++" in C++?

the "If idxCL >= color_list.Count Then idxCL = 0 End If...."
So, this is saying that if "idxCL" is greater than or eaqual to the number of colors in the list, that it will reset the variable to 0?
Which I assume is what sets the panel color back to its original state.

What I dont understand, is where we told the program that 0=orignal color.
Is this because it is the first item in our list?

Sorry in advance for the noob questions

---

The first item in the list is the color you define for the panel in the designer, which may or may not be what you want. If it isn't then just remove the .Add statement. The first item in the list is at index 0.

+=1 is the same as ++, a shame that VB didn't adopt the same syntax.

Thank you very much for your help!
Works like a charm.

If I knew how to rate comments - I would :(

If you want to give rep to dbasnett (or anyone else for that matter), you can do so very easily. If you look at his post, follow his name directly down. The next thing you will see is a star and a triangle with an exclamation mark in it. Click on the star to give him extra rep. That doesn't rate his post but it rates his help and increases his standing on the forum.