将文本框中的数字乘以数量值

Question

我有一个名为Amount的TextBox和一个名为quantity1的NumericUpDown。如何将双倍的TextBox与NumericUpdown的值相乘？

double amt;
double ans;

amt = Double.Parse(Amount.Text);
tot = Double.Parse(Total.Text);

//I have another textbox called total.
ans = amt * (quantity1.Value) //how do i do this? it has error.

Answer 1

在应用乘法后将quantity1.Value的值转换为double AND，然后将结果转换为字符串并分配给文本框，它可以解决您的问题

Answer 2

double amt = Convert.ToDouble(Amount.Text);
double qnt = Convert.ToDouble(quantity.Value);
double ans = amt * qnt;
Total.Text = ans.ToString();