Update MainWindow.xaml.cs

[luisgomesgoncalves]

Purpose

This changes solves an error found when implementing this code in visual studio

Does this introduce a breaking change?

[ ] Yes
[ x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ x ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]
git checkout [branch-name]
npm install

• Test the code

Just need to implement it on visual Studio

What to Check

Verify that the following are valid
Verify that the error:

is not being triggered.

Other Information