For example, you could display an error message, change the field’s background color, or at least beep to let the user know that focus did not leave the field because something is wrong. The event triggers even if the user tries to close the form.
Somehow, though, I can't seem to validate it automatically in C# without specifying the schema to validate against like so: Xml Document asset = new Xml Document(); Xml Text Reader schema Reader = new Xml Text Reader("relative Schema Path"); Xml Schema schema = Xml Schema.
Read(schema Reader, Schema Validation Handler); asset.
would somebody show me a convenient way to validate Textbox's value are not null or empty in Winform.
if-else condition is only good for fewer textboxs in a winform or solution, if(Textbox1.text==null) else but if there are lots of textbox?
When you run the page and click one of the buttons, you will see that the checkbox will have a Required Field Validator. But it works only on serversde, requiring a postback to use it.