class A : System...Forms.Form
{}
class B : A //designer for class B -O'K
{}
class C : B //designer for class C - ERROR
{}
Why does the designer screen of VS show me a big X instead of the form and say:
"The service System.Windows.Forms.Design.IEventHandlerService already exists in the service container. Parameter name: serviceType."
It seems/appears I'm duplicating something. If I state "class C : A" everything is O'k but the DataSet I need is in class B.
Steve
Bases classes & Forms
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Bases classes & Forms
Uminder
hi, your solution did not work.
heres my code (and I am still getting the error)
private void FrmBaseDataForm_Load(object sender, EventArgs e) {
// Check if Design Mode : Cause Error
if (!DesignMode){
DoBindControls();
}
}
rthiney
if not designmode then
'your code
end if
You see when you inherit a form in another form, it runs the load in the base form and if the load in the base form has some operation that fails then you get error on the form inheriting the base form.
Hope this helps.
Cimares
I would add that I used VS'es 'visual inheritance' mechanism to derive B from A and then C from B. Also I left the signature for constructors B() and C() alone, they are the standard constructors generated by VS. I did it as 'VS friendly' as I could.
I can see the design view for B. At first I could see the design view for C, but then I closed VS and after reopening I can't see it any more. However the program compiles and runs just fine.