The automatic sizing behavior of the column is determined by the value of the DataGridViewColumn.InheritedAutoSizeMode property, which is the same as the value of the DataGridViewColumn.AutoSizeMode property for all values except DataGridViewAutoSizeColumnMode.NotSet, which indicates that the value is inherited from the DataGridView.AutoSizeColumnsMode property instead.

When the DataGridViewColumn.InheritedAutoSizeMode property value is DataGridViewAutoSizeColumnMode.Fill, the column is resized along with other columns in that mode so that all visible columns in the control exactly fill the horizontal width of the available display area. All fill-mode columns in the control divide the available space in proportions determined by their DataGridViewColumn.FillWeight property values. For more information about column fill mode, see Column Fill Mode in the Windows Forms DataGridView Control.

When the DataGridViewColumn.InheritedAutoSizeMode property is set to any other value except DataGridViewAutoSizeColumnMode.None, the column will manage its width so that its cell values are fully displayed without clipping. In content-based sizing modes, size adjustments occur whenever cell contents change or, if DataGridViewCellStyle.WrapMode is enabled, whenever row heights change. Some content-based sizing modes let you limit the size adjustment to the currently displayed rows in order to increase performance.

Only columns with a DataGridViewColumn.Visible property value of true are resized, and changing the visibility of a column does not cause resizing to occur. Additionally, when columns are set to automatically resize, the user cannot adjust the column widths with the mouse.

To adjust column widths programmatically, use the System.Windows.Forms.DataGridView control's erload:System.Windows.Forms.DataGridView.AutoResizeColumn or erload:System.Windows.Forms.DataGridView.AutoResizeColumns methods or set the column DataGridViewColumn.Width property.

For more information about content-based automatic sizing, see Sizing Options in the Windows Forms DataGridView Control.