How to Copy Visual Classes to Other Libraries

MORE INFORMATION

It is sometimes necessary to copy a class from one library to another. You can copy a class using one of the following three methods.

Method One: Use the ADD CLASS Command

The ADD CLASS command adds a class to a class library. The OF clause of the ADD CLASS command allows you to add a class from another class library. For example, if you have a class called Class1 in a library called Mylib and want to copy the class to another library, you can use this command:

   ADD CLASS class1 OF mylib1 TO mylib2
				

Method Two: Use the Project Manager

You can drag and drop a class from a class library to another one in a project.

1. Open a project, and add two classes to it.
2. Select the Class Library tab, and drill down the class library to see all of the classes contained in the .VCX file.
3. Click a class in the source class library, and drag it to the destination library.

The class is copied from one library to the other. You can also open two different projects and drag a class from one project to the other.

Method Three: Use the Class Browser

You can drag a class between two instances of the Class Browser.

1. Choose Class Browser from the Tools menu.
2. Open a class library, and select the class you want to copy.
3. Open a second instance of the Class Browser.
4. Drag the class you want to copy from one instance of the Class Browser to the second instance. To do this, drag the class icon below the Type combo box from the source library to the class icon picture in the second instance of the Class Browser.

Copying a class from one class library to another class library adds a record to the .VCX file. If a class is subclassed, a reference to the initial location of the parent class exists, and it is not changed when you copy the class to a different .VCX file. If you want to maintain inheritance without providing the two .VCX files, you need to edit the class to modify this reference, and you need to copy the parent class to the new library. You can use the Class Browser to achieve this.

1. Start an instance of the Class Browser, and select the class you just copied.
2. Select the Redefine button to change the reference to the parent class. In the 'As' textbox, type the name of the parent class, and in the 'Of' textbox, select the name of the new class library.