Question

Is there a better way to do “input forms” in WebForms?

I always end up with code like this:

Double d = 0; // chuckle inside
if(Double.TryParse(myNumberTextField.Text, out d))
{
    myObject.DoubleVal = d;
}

Is there a better way to process free-form “numeric” input.

Answer 1

You can validate the textbox using a compare validator, and then if the page passes validation use the double.Parse method.

<asp:TextBox ID="txtDouble" runat="server"></asp:TextBox>
    <asp:CompareValidator ID="CompareValidator1" runat="server" 
        ErrorMessage="Input must contain a double." ControlToValidate="txtDouble" 
        Operator="DataTypeCheck" SetFocusOnError="True" Type="Double"></asp:CompareValidator>
<br />
<asp:Button ID="btnSubmit" runat="server" Text="Submit" />

/*C#*/
protected void btnSubmit_Click(object sender, EventArgs e)
{
    if (Page.IsValid)
    {
        double d = double.Parse(txtDouble.Text);
    }
}