This property controls the display of multiple lines of text in edit cells in the band or the grid controlled by the specified override. When True, text will wrap in the area of the cell. If the RowSizing property is set to automatically resize the row, the row will expand in height until all lines of text are displayed (or the number of lines specified by the RowSizingAutoMaxLines property is reached).
The CellMultiLine property does not pertain to multi-line editing, only display. Also, you should note that setting a cell to multi-line mode will disable data masking. Only single-line cells can be masked (using the MaskInput and MaskDisplayMode properties.)
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2