CODEWITHSUNDEEP
vb.netwinformsinheritance
Rob.Jaix
Rob.Jaix

Reputation: 13

Inheritance causes class to act like it is Shared

When using inheritance on Winforms, it causes the class to appear Shared. Why only the second line in the Main method displays a syntax warning? TestForm102.Widgets.Count should highlight the same issue.

Note: I added the MustInherit to TestForm101 to highlight the issue (...what it should display). If I remove it, the form simply acts like it is shared too.

enter image description here

Upvotes: 1

Views: 98

Answers (1)

Bjørn-Roger Kringsjå
Bjørn-Roger Kringsjå

Reputation: 9981

The first line works because TestForm102 is an instance of TestForm102 rather than a type as one would expect. It's auto-generated by VS and you'll find it in My.Forms. You're last line fails because VS cannot auto-generate an instance of a MustInherit form and/or a form without a public parameterless constructor. At this point TestForm101 is a type, and as observed, you cannot reference a non-shared member without an object reference. 

Dim y As Integer = My.Forms.TestForm102.Widgets.Count '<-Ok
Dim x As Integer = My.Forms.TestForm101.Widgets.count '<-Error

Error: 'TestForm101' is not a member of ...MyForms

Upvotes: 2

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