In order for the user to change the column width by dragging the mouse, DisplayOptions.columnResizable should be specified as true first. And, in order to change the fixed column width, fixedColumnResizable should also be set as true.
When the settings above have been specified as true, you can also specify GridColumn.resizable to separately set whether to change the width of each column. In addition, basically the width of child columns cannot be changed if it has set not to change the width of the parent column, but if DisplayOptions.checkChildColumnResizable is specified as false, the user will be able to change the width.
: If it is false, the width of all columns cannot be changed.
: If it is true, the width of fixed columns can be changed.
: Check if the parent column is resizable before changing the width of child columns.
: You can specify whether to change the width of column through resizable property.
: Specify whether to change the width of parent column of selected column.