Dynamically add rows and columns in WPF

AddRows&Columns.cs

ContentPanel.ColumnDefinitions.Clear();
ContentPanel.RowDefinitions.Clear();
int numColumnsToAdd = 4;
int numRowsToAdd = 4;
for (int column = 0; column < numColumnsToAdd; column++)
{
    ColumnDefinition cd = new ColumnDefinition();
    cd.Width = new GridLength(200);
    ContentPanel.ColumnDefinitions.Add(cd);
}

for (int row = 0; row < numRowsToAdd; row++)
{
    RowDefinition rd = new RowDefinition();
    rd.Height = new GridLength(200);
    ContentPanel.RowDefinitions.Add(rd);
}
//add an image into each 
for (int row = 0; row < numRowsToAdd; row++)
{
    for(int col = 0; col < numColumnsToAdd; col++)
    {
        TextBlock txt = new TextBlock();
        txt.Text = "Hello";
        ContentPanel.Children.Add(txt);
        Grid.SetColumn(txt, col);
        Grid.SetRow(txt, row);
    }
}