Dynamically Populate a UWP Grid using C#

This technique works for columns and rows, you just have to use the correct definition object, ColumnDefinition or RowDefinition.

Note the references to your specific grid instance (e.g. myGrid) and Grid methods (e.g. Grid.SetRow()).

myGrid.Children.Clear();
myGrid.ColumnDefinitions.Clear();

ColumnDefinition colDef;

for(int i = 0; i < myArray.Length; i++)
{
  colDef = new ColumnDefinition();
  myGrid.ColumnDefinitions.Add(colDef);
  colDef.MinWidth = 50;

  // Create a new instance of a TextBlock
  // or any other control; making a factory 
  // method(s) is usually wise.
  TextBlock txt = MyTextBlockFactoryMethod();
  myGrid.Children.Add(txt);
  Grid.SetRow(txt, 0);
  Grid.SetColumn(txt, i);
  txt.Text = myArray[i].ToString();
}