when I run the folder picker after creating a new tab, the app returns Null and an error occurs.

Question

Right now I am trying to create a TabView based photo app in the WinUI3 development environment.

I am trying to create an app where every time I create a new tab, a tab with the same content is created.

The content of the tabs will implement a folder picker function.

However, when I run the folder picker after creating a new tab, the app returns Null and an error occurs.

Why is this?

Answer 1

Hello there,

This error occurs when you use a bang operator (!) on a nullable instance which wasn't initialized.

For example:

String? string; // Nullable String

void main() {
  var len = string!.length; // Runtime error: Null check operator used on a null value
}

Solutions:
Open the logs and there must be a line pointing to a file in your project where the error occurred.

Hope this resolves your Query !!

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