Testing COM Interfaces at Run Time

Testing COM Interfaces at Run Time

VB5 provides interface inheritance through the use of the Implements keyword. For example, CFullTimeEmployee can implement the IEmployee interface. This interface might include basic information such as name, social security number, and date of birth. Another class, CPartTimeEmployee can also implement the IEmployee interface. You can then write code against the IEmployee interface without regard to the type of employee. To supply additional functionality, you might create an IEmp2 interface. To test whether an object is of a certain type, use the TypeOf keyword at run time. The format is “TypeOf object Is class/interface”. Here’s how to define two classes:

 Class CFullTimeEmployee:Implements IEmployeeImplements IEmp2Class CPartTimeEmployeeImplements IEmployeeDim objMyFTE as New CFullTimeEmployeeDim objMyPTE as New CPartTimeEmployee

Using TypeOf, you can query at run time which interfaces these objects support:

 Query	ReturnTypeOf objMyFTE Is CFullTimeEmployee	TrueTypeOf objMyFTE Is IEmployee	TrueTypeOf objMyFTE Is IEmp2	TrueTypeOf objMyFTE Is CPartTimeEmployee	FalseTypeOf objMyFTE Is Object	TrueTypeOf objMyFTE Is IUnknown	TrueTypeOf objMyPTE Is CPartTimeEmployee	TrueTypeOf objMyPTE Is IEmployee	TrueTypeOf objMyPTE Is IEmp2	FalseTypeOf objMyPTE Is Object	TrueTypeOf objMyPTE Is IUnknown	TrueTypeOf objMyPTE Is CFullTimeEmployee	False
Share the Post:
XDR solutions

The Benefits of Using XDR Solutions

Cybercriminals constantly adapt their strategies, developing newer, more powerful, and intelligent ways to attack your network. Since security professionals must innovate as well, more conventional endpoint detection solutions have evolved

AI is revolutionizing fraud detection

How AI is Revolutionizing Fraud Detection

Artificial intelligence – commonly known as AI – means a form of technology with multiple uses. As a result, it has become extremely valuable to a number of businesses across

AI innovation

Companies Leading AI Innovation in 2023

Artificial intelligence (AI) has been transforming industries and revolutionizing business operations. AI’s potential to enhance efficiency and productivity has become crucial to many businesses. As we move into 2023, several

data fivetran pricing

Fivetran Pricing Explained

One of the biggest trends of the 21st century is the massive surge in analytics. Analytics is the process of utilizing data to drive future decision-making. With so much of

kubernetes logging

Kubernetes Logging: What You Need to Know

Kubernetes from Google is one of the most popular open-source and free container management solutions made to make managing and deploying applications easier. It has a solid architecture that makes

ransomware cyber attack

Why Is Ransomware Such a Major Threat?

One of the most significant cyber threats faced by modern organizations is a ransomware attack. Ransomware attacks have grown in both sophistication and frequency over the past few years, forcing

data dictionary

Tools You Need to Make a Data Dictionary

Data dictionaries are crucial for organizations of all sizes that deal with large amounts of data. they are centralized repositories of all the data in organizations, including metadata such as