Tham khảo các Thư viện Type Trước khi nhìn thấy làm thế nào để sử dụng các bộ sưu tập và các đối tượng, bạn cần phải biết làm thế nào để tham khảo các thư viện mô hình đối tượng để sử dụng. Các mô hình đối tượng được tìm thấy trong các thư viện loại trong hệ thống tập tin
Referencing the Type Libraries
Before seeing how to use these collections and objects, you need to know how to
reference the object model libraries for use. The object models are found in type libraries
in the file system. A type library contains the information about the object models such as
the collections, properties, and methods. Referencing the type libraries isn't difficult, but
it is still very important.
Because Visual Basic .NET uses ADO.NET by default, you will have to reference all the
object models you are going to need. To reference the object models, choose Add
Reference from Visual Studio .NET's Project menu. After you're in the Add Reference
dialog box, click on the COM tab. You then have to find the type libraries for the object
models and select them. The type library name that you will be using is as follows:
Microsoft ActiveX Data Objects 2.7 Library. This is also referred to as the ADODB
You can see this library, as well as other Microsoft ActiveX Data Objects Libraries, in
Figure A.2. Registering the COM type libraries.
You can use both ADO libraries and ADO.NET classes in the same
application without worrying about the order of libraries in the
references. This is great when you're converting applications from ADO
to ADO.NET. To use all libraries and not worry about the order of
reference, you must prefix your objects with the library with which they
come. Here are some examples, with the specific library types:
Dim odaTest as OLEDB.OLEDBDataAdapter
Dim rstTestADO as ADODB.Recordset
Dim catTest as ADOX.Catalog
Although not all objects are shared between the libraries, it's a good idea
to specify the library while you're getting used to the objects.
After the library has been selected, you can see the ADODB reference entry in the
Solution Explorer under references.