Gets or sets a value indicating whether the value of the editing control differs from the value of the hosting cell.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
The property is set to true to indicate that the hosting cell's state has changed and its user interface (UI) needs to be updated to reflect this change in value. The owning cell or table will reset this property to false after an update.Notes to Implementers
Returning true in your implementation of this property does not automatically change the displayed value. When the value changes in the editing control, you must notify the DataGridView of the change by passing true to the DataGridView.NotifyCurrentCellDirty method.