C＃如何修改控件的属性

Question

I get a control from customers. just a dll file.

it like a textbox. use user to input the value, now as called SUTextBox .

it have a property "IsemailValidation=true", then it can validate email address.

now ,I have a request like this. if user input value ,then validate it ,

if user don't input value ,then don't validate ,just get empty data(this control cannot be empty if set IsemailValidation=true ).

The key question is that,if I set IsemailValidation=true . this textbox cannot be empty. and I want to it can be empty or have valid email address.

Can I set the property somewhere dynamic?

Answer 1

I bet your SUTextBox should have some TextChanged event and we can handle this event like this:

sUTextBox1.TextChanged += (s,e) => {
   bool validate = !(sUTextBox1.Text == "");
   if(sUTextBox1.IsemailValidation!=validate) 
     sUTextBox1.IsemailValidation = validate;
};