This event is fired when the user starts changing the content of a cell in a Grid control. The EVENT-DATA-1 and EVENT-DATA-2 data items contain the column and the row number (respectively) of the modified cell. The X and Y properties are automatically set to the value of the cell coordinates, until the user leaves that cell.

Setting EVENT-ACTION to EVENT-ACTION-FAIL allows you to protect the cell from being edited. In this way you can create read-only cells, but this method is less performing than using the Cell-Protection property.