Desktop Application Desktop Application Performance 1

Question 1

What is the main cause of a desktop application's UI becoming unresponsive or 'freezing'?

Accepted Answer

A long-running operation blocking the main UI thread

Answer

When heavy computation or I/O runs on the main UI thread, it blocks the event loop from processing input and paint events, causing the UI to freeze.

Question 2

What is the purpose of caching in a desktop application?

Accepted Answer

Store frequently accessed data in fast memory to avoid redundant computation or I/O

Answer

Caching saves the result of expensive operations so subsequent requests can be served from fast memory instead of repeating the computation or disk/network access.

Question 3

What does 'startup time' optimization in a desktop application typically involve?

Accepted Answer

Deferring non-essential initialization until after the main window appears

Answer

By showing the main window quickly and loading plugins, data, and secondary features lazily in the background, perceived and actual startup time is reduced.

Question 4

Which profiling tool is used on Windows to analyze CPU performance hotspots in desktop applications?

Accepted Answer

Windows Performance Analyzer (WPA) / Visual Studio Profiler

Answer

Windows Performance Analyzer and the Visual Studio Profiler provide CPU sampling and instrumentation to identify functions consuming the most execution time.

Question 5

What is 'virtual scrolling' and why is it used in desktop applications with large data lists?

Accepted Answer

Rendering only visible rows instead of all rows to reduce DOM/widget overhead

Answer

Virtual scrolling creates and renders only the list items currently visible, recycling widgets as the user scrolls, which dramatically reduces memory use and rendering time for large datasets.

Desktop Application Practice Test

Desktop Application Practice Test

Desktop Application Desktop Application Performance 1