来自多个句柄的Sender.Gettype

Question

I have code that handles multiple events. FYI - I use Devexpress Components. I have two items, a Lookupedit and a GridLookupEdit, that are handled by the same code. I am trying to do something like the following:

    Dim type = sender.GetType()

    Select Case DirectCast(sender, Type).Name
        Case "mgrLUE"
            log("View metrics for manager: " & mgrLUE.Properties.GetDisplayText(mgrLUE.EditValue), Me.Name)
        Case "sectLUE"
            log("View metrics for section: " & sectGLUE.Properties.GetDisplayText(sectGLUE.EditValue), Me.Name)
    End Select

I am getting errors at the select case line. I cant figure out how to dynamically get the type to be able to direct cast to it. The types will be DevExpress.XtraEditors.GridLookUpEdit and DevExpress.XtraEditors.LookUpEdit in this case. I have tried searching for a solution, but everything I have tried is failing.

Thank you for the help.

Answer 1

Casting can't be done dynamically because its sole purpose is to let the compiler know that you expect an object to be of a certain type. This is necessary so that the compiler knows what members the object contains when you try to access it.

I should mention that VB.NET has a feature called late binding , which allows you to access members of a type wrapped in an Object by looking up if the member you're trying to access exists at runtime. Using late binding, however, is not recommended as it is very easy to make mistakes and break your code.

Now, as for your problem: Casting can be done if an object is of a certain type, or if it inherits from that type. Since I'm guessing what you're using are controls (that you've placed on your form) they all should inherit from System.Windows.Forms.Control , thus you can cast them to that which contains the base property Name :

Select Case DirectCast(sender, Control).Name