Question

In my application I have TextBox in a FormView bound to a LinqDataSource like so:

<asp:TextBox ID='MyTextBox' runat='server'               Text='<%# Bind('MyValue') %>' AutoPostBack='True'               ontextchanged='MyTextBox_TextChanged' />  protected void MyTextBox_TextChanged(object sender, EventArgs e) {     MyFormView.UpdateItem(false); } 

This is inside an UpdatePanel so any change to the field is immediately persisted. Also, the value of MyValue is decimal?. This works fine unless I enter any string which cannot be converted to decimal into the field. In that case, the UpdateItem call throws:

LinqDataSourceValidationException – Failed to set one or more properties on type MyType. asdf is not a valid value for Decimal.

I understand the problem, ASP.NET does not know how to convert from ‘asdf’ to decimal?. What I would like it to do is convert all these invalid values to null. What is the best way to do this?

Answer 1

I think you should handle the Updating event of the LinqDataSource on your page. Do your check for invalid strings (use a TryParse method or something) and then continue with the base class update.

(Edit: My intuition lines up with what’s recommended here)