Using buttons on a form.

Brian_TheLion

A lot of books deal with the console side of c# more than the form side. Question. I have a form that has a start, yes, no button. When I click on start a question is displayed on the form and the user click on either the yes or the no button. How do I tell the main program what button has been pressed? When I say 'main program' I mean the part of the program that's ran when the start button is pressed. At the start the program YN = 0. If the No button is pressed then YN = 1 and if the Yes button is pressed then YN = 2. What happens next depends on what button is pressed so I need to get this information but to the main program.

OriginalGriff

Brian_TheLion wrote:

A lot of books deal with the console side of c# more than the form side.

I'd disagree with that, quite strongly: most "beginner" books start with the Console, because it's a lot easier to get your head round - but quickly move away to WinForms or WPF because that's what gets used in the real world. Certainly, all the Addison Wesley, Wrox, and Microsoft Press books that I've read do! But it's pretty easy - it all works via Events. When you click the button, it generates an Event called "Click" which the Form (or another container like a UserControl perhaps) handles. Open your form in the designer. Double click the button. That will add a Click event handler to the form and open the code window to let you type code into the handler method. Type your code:

        MessageBox.Show("The Yes button was clicked", "My form event handler", MessageBoxButtons.OK, MessageBoxIcon.Information);

And run your app. Click the button, and the message will appear! You code will look like this:

    private void YesButton\_Click(object sender, EventArgs e)
        {
        MessageBox.Show("The Yes button was clicked", "My form event handler", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

Because the system will add the handler method framework for you:

private So that it is only usable inside the form.
void Because it doesn't return a value
YesButton_Click Name of the handler method: YesButton Click event
object sender "sender" is object that raised the event (useful if several buttons share the same handler)
EventArgs e Provides extra information on the event if you need it.

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GenJerDan

I think what you're asking is how to get the result of the click back to the main form. When you open the form that has the buttons, use .ShowDialog, rather than just .Show, and the results of the button click (as OrginalGriff showed) can be returned to the calling form easily.

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BillWoodruff

First, are you using one Form for all this, or more than one Form ?

«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali

BillWoodruff

From what the OP describes, I cannot tell if he is using a separated Form to display the quesstion.

«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali

Brian_TheLion

Thanks Bill and RenJerDan for your replies. To go more into detail. Once the user has pressed the start button a d the question is displayed to the user then the user has a choice of clicking on the YES or the NO buttons. For a forms program once the program has displayed the question it is waiting for the user to press a button on the form, but if the user pressed the YES button then control switches to the Yes_Click code which is just YN=1 but then I need to return to the main code to make a decision depending on what button was pressed. It's not like the main code will wait for the user to make a choice before continuing. I tried to create a loop that continues until YN is equal to anything other than zero but while in the loop it is not checking on the buttons on the form, which Makes me wonder how arcade games work as they are looping to provide animation.

BillWoodruff

@Brian_TheLion Hi Brian, I still don't know if the question is displayed in its own Form, rather than on a "Main Form." That's important to know in order to assist you. cheers, Bill

«One day it will have to be officially admitted that what we have christened reality is an even greater illusion than the world of dreams.» Salvador Dali

Brian_TheLion

I'm using one form only Bill. Brian

BillWoodruff

Here's how I would approach this: flow-of-control: a GroupBox is shown with a current question; the user must click one of two radio-buttons to enable a Button that moves to the next question. Next questions are presented until the list of questions is enumerated. 0 a Button that will start the quiz 'btnShowQuiz: visible on the Main Form 1 a GroupBox 'grpbxQuiz: set not visible containing:

 a TextBox 'tbxQuizQuestion 
    
 two RadioButtons 'rbtnYes 'rbtnNo : the 'CheckChanged for both these RadioButtons is set to 'rbtn\_CheckedChanged
     
 a Button 'btnNextQuestion

// used to reset RadioButton state
private bool ignoreRBCheckEvent = true;

private List questions = new List
{
"who", "when", "where", "how"
};

// holds results
private Dictionary QA = new Dictionary();

// question counter
private int qcnt = 0;

// show the quiz
private void btnShowQuiz_Click(object sender, EventArgs e)
{
QA.Clear();
qcnt = 0;

tbxQuizQuestion.Text = questions\[0\];

btnNextQuestion.Enabled = false;

rbtnYes.Enabled = true;
rbtnYes.CheckedChanged += rbtn\_CheckedChanged;

rbtnNo.Enabled = true;
rbtnNo.CheckedChanged += rbtn\_CheckedChanged;

ignoreRBCheckEvent = false;

grpbxQuiz.Visible = true;

// set the clip
Cursor.Clip = grpbxQuiz.RectangleToScreen(grpbxQuiz.ClientRectangle);

}

private void BtnNextQuestion_Click(object sender, EventArgs e)
{
ignoreRBCheckEvent = true;

rbtnYes.Checked = false;
rbtnNo.Checked = false;

btnNextQuestion.Enabled = false;

tbxQuizQuestion.Text = questions\[qcnt\];

ignoreRBCheckEvent = false;

}

private void rbtn_CheckedChanged(object sender, EventArgs e)
{
if (ignoreRBCheckEvent) return;

QA.Add(qcnt++, rbtnYes.Checked);

if (qcnt < questions.Count)
{
    btnNextQuestion.Enabled = true;
}
else
{
    // release the clip
    Cursor.Clip = Rectangle.Empty;
    grpbxQuiz.Visible = false;
    OnQuizFinished();

}

}

// inspect the results
public void OnQuizFinished()
{
foreach (var kvp in QA)
{
Console.WriteLine($"({kvp.Key}) \"{questions[kvp.Key]}\" | {kvp.Value}");
}
}

note the use of clipping the Cursor to restrict mouse input to the GroupBox.

«One day it will have to be officially admitted that what we

Brian_TheLion

Thanks Bill for the example code you provided. I'll study it and try it out. Brian