What is that vertical and horizontal line for when you click on the Form?

Question

I wanted to know what that vertical and horizontal line is for when you click on the form and it is there, then dps when you click again, another line appears. And how can I get these lines?

Answer 1

These rows are the row and column definitions of a Grid, and server to organize the layout of the application (View Image). You can add them by clicking on the outermost part of the component (an orange line will appear where the line will be added), and you can remove it by clicking two clicks on the starting point of the line (that down arrow).

It is also possible to remove them by code XAML:

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="79*"/>
        <RowDefinition Height="240*"/>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="142*"/>
        <ColumnDefinition Width="375*"/>
    </Grid.ColumnDefinitions>
</Grid>