ISSUE #2072

1% 2% could not be resolved because it was within the generic namespace 3%.

Description

This occurs when a generic class (like Form class) is used and then a method specific of some classes that inherits from that class, are called, those methods are late binded so, VB6 could resolved (if it exists on the object), but in .Net this is not possible.

Recommendations

Define an Interface and make all the forms that are ussed in those clases implement it. Then use the interface instead of using the generic class (in the example Form Class).

Sample VB6

Form1 Code

PublicSub ObjectMethod()

MsgBox("Form1")

EndSub

Form2 Code

PublicSub ObjectMethod()

MsgBox("Form2")

EndSub

Module Example

PublicSub CallMethodInForm(ByVal F As Form)

F.ObjectMethod()

EndSub

PublicSub Test()

Dim F1 AsNew Form1

Dim F2 AsNew Form2

CallMethodInForm(F1)

CallMethodInForm(F2)

EndSub

Target VB.NET

Form1 Code

Inherits System.Windows.Forms.Form

PublicSub ObjectMethod()

MessageBox.Show("Form1", Application.ProductName)

EndSub

Form2 Code

Inherits System.Windows.Forms.Form

PublicSub ObjectMethod()

MessageBox.Show("Form2", Application.ProductName)

EndSub

Module Example

PublicSub CallMethodInForm(ByVal F As Form)

'UPGRADE_ISSUE: (2072) Control ObjectMethod could not be resolved because it was within the generic namespace Form.

F.ObjectMethod()

EndSub

PublicSub Test()

Dim F1 AsNew Form1

'UPGRADE_ISSUE: (2068) Form2 object was not upgraded.

Dim F2 AsNew Form2

CallMethodInForm(F1)

'UPGRADE_WARNING: (1068) F2 of type Form2 is being forced to VB.Form.

CallMethodInForm(F2)

EndSub

Expected VB.NET

Add an Interface

PublicInterface FormInterface

Sub ObjectMethod()

EndInterface

Form1 Code

Inherits System.Windows.Forms.Form

Implements FormInterface

PublicSub ObjectMethod() Implements FormInterface.ObjectMethod

MessageBox.Show("Form1", Application.ProductName)

EndSub

Form2 Code

Inherits System.Windows.Forms.Form

Implements FormInterface

PublicSub ObjectMethod() Implements FormInterface.ObjectMethod

MessageBox.Show("Form2", Application.ProductName)

EndSub

Module Example

PublicSub CallMethodInForm(ByVal F As FormInterface)

F.ObjectMethod()

EndSub

PublicSub Test()

Dim F1 AsNew Form1

Dim F2 AsNew Form2

CallMethodInForm(F1)

CallMethodInForm(F2)

EndSub

Target C#

Form1 Code

internalpartialclassForm1

: System.Windows.Forms.Form

{

publicvoid ObjectMethod()

{

MessageBox.Show("Form1", Application.ProductName);

}

}

Form2 Code

internalpartialclassForm2

: System.Windows.Forms.Form

{

publicvoid ObjectMethod()

{

MessageBox.Show("Form2", Application.ProductName);

}

}

Module Example

staticpublicvoid CallMethodInForm( Form F)

{

//UPGRADE_ISSUE: (2072) Control ObjectMethod could not be resolved because it was within the generic namespace Form.

F.ObjectMethod();

}

staticpublicvoid Test()

{

Form1 F1 = newForm1();

Form2 F2 = newForm2();

CallMethodInForm(F1);

CallMethodInForm(F2);

}

Expected C#

Add an Interface

interfaceFormInterface

{

void ObjectMethod();

}

Form1 Code

internalpartialclassForm1

: System.Windows.Forms.Form, FormInterface

{

publicvoid  ObjectMethod()

{

MessageBox.Show("Form1", Application.ProductName);

}

}

Form2 Code

internalpartialclassForm2

: System.Windows.Forms.Form, FormInterface

{

publicvoid  ObjectMethod()

{

MessageBox.Show("Form2", Application.ProductName);

}

}

Module Example

staticpublicvoid CallMethodInForm(FormInterface F)

{

F.ObjectMethod();

}

staticpublicvoid Test()

{

Form1 F1 = newForm1();

Form2 F2 = newForm2();

CallMethodInForm(F1);

CallMethodInForm(F2);

}