void EnsureRowsColumnsInitialized()
{
_columns = ColumnDefinitions == null ? new List <ColumnDefinition>() : ColumnDefinitions.ToList();
_rows = RowDefinitions == null ? new List <RowDefinition>() : RowDefinitions.ToList();
int lastRow = -1;
for (var index = 0; index < InternalChildren.Count; index++)
{
Element w = InternalChildren[index];
lastRow = Math.Max(lastRow, GetRow(w) + GetRowSpan(w) - 1);
}
lastRow = Math.Max(lastRow, RowDefinitions.Count - 1);
int lastCol = -1;
for (var index = 0; index < InternalChildren.Count; index++)
{
Element w = InternalChildren[index];
lastCol = Math.Max(lastCol, GetColumn(w) + GetColumnSpan(w) - 1);
}
lastCol = Math.Max(lastCol, ColumnDefinitions.Count - 1);
while (_columns.Count <= lastCol)
{
_columns.Add(new ColumnDefinition());
}
while (_rows.Count <= lastRow)
{
_rows.Add(new RowDefinition());
}
for (var index = 0; index < _columns.Count; index++)
{
ColumnDefinition col = _columns[index];
col.ActualWidth = -1;
}
for (var index = 0; index < _rows.Count; index++)
{
RowDefinition row = _rows[index];
row.ActualHeight = -1;
}
}
