Trying to multiply the input from a text box and show the result on a label, but getting an error

Question

    decimal aPrice = 15.75m;

    decimal aSales = decimal.Parse(txtASales.Text);

    decimal aRev = (aPrice * aSales);

    private void btnCalculate_Click(object sender, EventArgs e)
    {
        lblARev.Text = aRev.ToString();
    }

This is the code i have for it, what I'm trying to do is multiply the price of A-type tickets and the number of A-type tickets sold. The number sold will be taken from the user in a text box "txtASales" which I got from the object window, and renamed in the properties window (no coding done for that). Then the revenue will be shown on a label "lblARev". I am getting an error "A field initializer cannot reference the non-static field, method, or property" for txtASales, aPrice, and aSales.

Answer 1

You cannot reference txtASales, aPrice or aRev outside of a method that you create or one of the .NET events. You could do this:

private void btnCalculate_Click(object sender, EventArgs e)
{
    decimal aPrice = 15.75m;

    decimal aSales = decimal.Parse(txtASales.Text);

    decimal aRev = (aPrice * aSales);

    lblARev.Text = aRev.ToString();
}

But you cannot reference non-static(txtSales, aPrice, aRev) at the class level if they are not static from a field initializer.