Double.TryParse Method (System) | Microsoft Docs[
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void BMR()
{
if (!double.TryParse(tbWeight.Text, out var weight))
{
MessageBox.Show("Enter a valid weight", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
if (!double.TryParse(tbHeight.Text, out var height))
{
MessageBox.Show("Enter a valid height", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
if (!double.TryParse(tBAge.Text, out var age))
{
MessageBox.Show("Enter a valid age", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
int bmr = 0;
if (rBMan.Checked)
{
bmr = Convert.ToInt32(66.47 + (13.75 * weight) + (5.003 * height) - (6.755 * age));
lblBMR.Text = lblBMR.Text + bmr;
}
else if(rBWoman.Checked)
{
bmr = Convert.ToInt32(655.1 + (9.563 * weight) + (1.85 * height) - (4.676 * age));
lblBMR.Text = lblBMR.Text + bmr;
}
else
{
MessageBox.Show("Select your Gender first", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}