birt barcode plugin EM ULATOR COMPON ENTS in vb

Insert qr codes in vb EM ULATOR COMPON ENTS

Summary

The RolesEdit user control allows an authorized user to edit the roles a resource can hold when assigned to a project. The simplest way to create such data maintenance forms is with the DataGridView control, because it can be directly bound to an editable root collection object such as ProjectTracker.Library.Roles.

Figure 20-5. Comparing interface-based and non-interface-based enumerators One possible problem with the non-interface enumerator implementation is that types from other assemblies might expect enumeration to be implemented using the interface method. If these objects attempt to get an enumeration of your class objects using the interface conventions, they will not be able to find them. To solve this problem, you can implement both forms in the same classes. That is, you can create implementations for Current, MoveNext, Reset, and GetEnumerator at the class level, and also create explicit interface implementations for them. With both sets of implementations, the type-safe, more efficient implementation will be called by foreach and other constructs that can use the non-interface implementations, while the other constructs will call the explicit interface implementations.