How to multiply two textbox values and display answer to third in c#?

Question

In my program have 3 textboxes. which are for subtotal,discount and grand total.Subtotal value will display after some calculations and I should type discount manually.Then after type discount value in textbox i need to display grandtotal value automatically in grandtotal textbox.How to do this.I try this

txtgrandtotal.Text = (Convert.ToDouble(txtdiscount.Text) * Convert.ToDouble(txtsubtotal.Text)).ToString();

But it didn't work for textchange event

Answer 1

You can do this with the TextChange Event on the TextBox txtdiscount control.

Once you added the event you can do your calculation like this:

private void txtdiscount_TextChanged(object sender, EventArgs e)
{
    txtgrandtotal.Text = (Convert.ToDouble(txtdiscount.Text) * Convert.ToDouble(txtsubtotal.Text)).ToString();
}