Deep Dive into App.StartScreen and App.OnStart: Leveraging Powerful Navigation and Initialization in Canvas Apps

If you're interested in building custom applications quickly and easily, then canvas apps might be the solution you need. With their low-code approach to app development, you can create data collection forms, process automation, data visualization, and more. As Microsoft continues to add new features and improvements to canvas apps, this blog post delves into two important properties of the App object: App.OnStart and App.StartScreen.

App.OnStart is used for one-time initialization and global app-level settings. It's crucial for performing initialization work, retrieving data, determining which screen will be displayed first, and more. However, if not optimized adequately, it can cause performance problems. This is because App.OnStart often includes dependencies on external resources or synchronous actions that require waiting for a response. With large amounts of data or multiple iterations, performance issues can significantly impact app performance.

To address these problems, Microsoft has introduced a new property: App.StartScreen. This property is a declarative method for setting the first screen that is shown when the app starts and improves loading speed while providing a better user experience. This property is a subset of App.OnStart, and you can use it to simplify the lifecycle of the app, avoid common pitfalls, optimize Power Apps, and write less code.

Overall, by using both properties effectively, you can significantly improve the performance of your canvas apps. App.OnStart plays a crucial role in global app-level settings, whereas App.StartScreen improves loading speed and provides a better user experience. Combining these two properties allows you to create canvas apps that are efficient, effective, and engaging for your users.