VB 2008 Question

[CollinMcGuire]

Okay so I need some help with radio buttons.
Basically what I am looking to do is make an "If...Then" statement but it needs to know which radio buttons were selected to finish the "then" part of the statement. What code would I use to do this?
I don't really want a spoiler, more of an explanation of how it actually works also.



I would Google it, but I don't know what I am looking for.

[jmcilhinney]

You've really got two choices:

1. When you need to know, use an If...ElseIf...EndIf statement to test the Checked property of each RadioButton to find the one that's True.

2. On the CheckedChanged event of each RadioButton, set a variable to a value that indicates which RadioButton is Checked. When you need to know, test that value.

By the way, in future can you please provide meaningful titles for your threads. With titles like "VB 2008 Question" how can we know which threads are relevant without opening and reading every single one? The title should describe the topic so people can decide whether or not they can help or be helped by the thread.

[CollinMcGuire]

Okay I understand what you were saying. But a classmate gave me the extremely simple answer that i really should have thought of...

if whateveryourradiobuttonis.checked = true then whatever

[jmcilhinney]

Okay I understand what you were saying. But a classmate gave me the extremely simple answer that i really should have thought of...

if whateveryourradiobuttonis.checked = true then whatever

Which is exactly what I said in option 1. If you only have two RadioButtons then just an If...Else will be enough but if you have three or more then you'll need at least one ElseIf in there too.

[CollinMcGuire]

Okay so I ran into another problem.
The app I am trying to create for a class is this...

A pizza business app. 
You will select the radio button that will select the type of pizza you want. 
then you can select it to be delivered or not. 
next you will select any other toppings. 
then the amount of pies you want. 
then hit the final cost button and get your final price.

so the problem i am having with it is, the math functions. I tried declaring a variable as integer set to 0 and then using the if then statements to add up the cost.

so here is an example.

dim intCost as integer

intCost=0


if CheesePizza.checked=true then intCost + 12

but all i get is syntax build errors. So what exactly is wrong?

[Tom.Net]

Dim intCost As Integer = 0
If rdoCheesePizza.Checked = True Then intCost += 12

[jmcilhinney]

First up, if you have a new question that isn't directly related to the topic of the thread, please create a new thread. The number of threads doesn't matter; what matters is keeping the forums organised. Keeping each thread to one topic, with a descriptive title, and each topic to one thread will help to do that.

Secondly, if you get errors then you get error messages. They are provided as an aid to diagnosing the problem. If you want us to diagnose the problem then you should pass those messages on to us. In this case it's easy to see what the issue is but that will not always be the case, so ALWAYS provide ALL the relevant information.

As for the question, you're letting the fact that you're writing code blind you to things that you already know and already do. Think about what you would do if you were performing the maths with a pen and paper. If you wanted to take the current value of intCost and increase it by 12 would you do it like this:

intCost + 12

No, you wouldn't. That doesn't change intCost at all. That just takes the current value of intCost and adds 12 to it. That produces a result but doesn't do anything with it. If you want to change the value of intCost then what have you got to do with that result?

[CollinMcGuire]

Well I'm guessing you would have to let the new cost be shown

[jmcilhinney]

Dim intCost As Integer = 0
If rdoCheesePizza.Checked = True Then intCost += 12

It appears that Tom's decided to do your thinking for you without providing any explanation so I'll expand a bit. What I was getting at it that you don't do just this:

intCost + 12

because that only produces a result. You have to assign that result back to intCost to change its value, i.e.

intCost = intCost + 12

What Tom has done is used a shorthand supported by VB for setting the value of a variable based on its current value. The code above can be shortened to:

intCost += 12

Various other operators can be shortened that way to including -, /, * and &.

[CollinMcGuire]

oh okay I get what you did with

intCost = intCost +12

it's the same thing that i learned with counters. I really should have realized that it would be the same type of math.

[JuggaloBrotha]

You've really got two choices:

1. When you need to know, use an If...ElseIf...EndIf statement to test the Checked property of each RadioButton to find the one that's True.

2. On the CheckedChanged event of each RadioButton, set a variable to a value that indicates which RadioButton is Checked. When you need to know, test that value.

By the way, in future can you please provide meaningful titles for your threads. With titles like "VB 2008 Question" how can we know which threads are relevant without opening and reading every single one? The title should describe the topic so people can decide whether or not they can help or be helped by the thread.

Kinda behind on this but you could do:

Select Case True
    Case RadioButton1.Checked
    Case RadioButton2.Checked
    '.....
End Select

Much cleaner than a bunch of ElseIf's

[chris128]

lol lets not get into the whole "Select Case vs If statement" thing again... there is already another thread for that