The content of a cell—assuming that it is not read-only—can be edited at runtime by the end user through the use of cell editors. Cell editors are created from DataTemplates (see Templates) and are used to edit the content of cells. Custom cell editors can be provided per column by setting a column's CellEditor property, or per data type through the DataGridControl's DefaultCellEditors property (see Cell Editors). A cell's IsCellEditorDisplayed property can be consulted to know if its editor is displayed.

Programmatically, the content of a cell can be edited when the parent row's or the cell's BeginEdit method is called, committed by the EndEdit method, and the modification canceled by the CancelEdit method.  At any time, the IsBeingEdited property can be consulted to determine if a cell's content is being edited, while the IsDirty property can be consulted to see if a cell's content has been modified. The Cell and Row classes also expose routed events (see Table 1 in Edit Events) that are triggered during various stages of the edit process and that can be handled by any parent element in the visual tree (bubbling).

When the value of a cell fails the validation process, its HasValidationError property will return true and its ValidationError property will contain a CellValidationError, which provides information on the cell in error, the error content, the exception (if one was thrown), and the validation rule that failed.  If the validation rule that failed is a binding-level ValidationRule, it will be wrapped in a PassthroughCellValidationRule. Validation errors will also be reported by a row when the value of one or more of its cells fails the validation process. Like cells, when a row contains validation errors, its HasValidationError property will return true and its ValidationError property will contain a RowValidationError, which provides information on the row in error, the error content, the exception, and the validation rule that failed.