DataGrid ItemsSource unexpected behavior

[Omcsesz]

Hello, Team!

I would like to report the following issue:
when I add a new item to a List, then I set it to be the ItemSource, this results in putting the two entries beside each other:

WpfApp1.zip

Is this normal?
Can you please support?

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[daisyTian0517]

The first entry is the DataGrid.Columns that you define yourself. The second entry is created by the AutoGenerateColumns="True" property.
You need add AutoGenerateColumns="False" to your DataGrid, DataGrid.AutoGenerateColumns is used to get or set a value that indicates whether the columns are created automatically. Its default value is True, so your DataGrid columns are created automatically.

[Omcsesz]

I see.
I fixed it, and it works now!