private void payrollCalculatorToolStripMenuItem_Click(object sender, EventArgs e)
{
PayrollCalculator objPayrollCalculator = new PayrollCalculator();
objPayrollCalculator.MdiParent = this;
objPayrollCalculator.Visible = true;
}
private void payrollCalculatorToolStripMenuItem1_Click(object sender, EventArgs e)
{
if (objPayrollCalculator == null)
{
objPayrollCalculator = new PayrollCalculator();
objPayrollCalculator.MdiParent = this;
objPayrollCalculator.FormClosed += ObjPayrollCalculator_FormClosed;
objPayrollCalculator.Visible = true;
}
else
{
objPayrollCalculator.Activate();
}
}
private void ShowPayrollCalculatorForm()
{
// Generate new instance if its not present already otherwise activate the already present instance so as to avoid generating multiple instances
if (payroll == null)
{
payroll = new PayrollCalculator();
payroll.MdiParent = this;
payroll.FormClosed += Payroll_FormClosed; // If not specified, then form instance does not become null
payroll.Visible = true; // Method 2 to Invoke form
}
else
{
// If instance is already present, activate it and give it focus
payroll.Activate();
}
}
// Set form instance to null on form close
private void Payroll_FormClosed(object sender, FormClosedEventArgs e)
{
payroll = null;
}
private void ObjPayrollCalculator_FormClosed(object sender, FormClosedEventArgs e)
{
objPayrollCalculator = null;
}
