Edit Data. Create Cell Editors. Validate User Input

string cellValue;
cellValue = gridView1.GetRowCellValue(2, "ID").ToString();

Dim CellValue As String 
CellValue = GridView1.GetRowCellValue(2, "ID")

string cellValue = gridView1.GetFocusedDisplayText();

Dim cellValue As String = GridView1.GetFocusedDisplayText()

gridView1.SetRowCellValue(gridView1.FocusedRowHandle, gridView1.FocusedColumn, "New Value");
//or
gridView1.SetFocusedValue("New Value");

gridView1.SetRowCellValue(gridView1.FocusedRowHandle, gridView1.FocusedColumn, "New Value")
'or
gridView1.SetFocusedValue("New Value")

    BaseEdit edit = null;
    private void gridView1_ShownEditor(object sender, EventArgs e)
    {
        GridView view = sender as GridView;
        edit = view.ActiveEditor;
        edit.EditValueChanged += edit_EditValueChanged;       
    }

    void edit_EditValueChanged(object sender, EventArgs e)
    {
        gridView1.PostEditor();
    }

    private void gridView1_HiddenEditor(object sender, EventArgs e)
    {
        edit.EditValueChanged -= edit_EditValueChanged;
        edit = null;
    }

    Private edit As BaseEdit = Nothing
    Private Sub gridView1_ShownEditor(ByVal sender As Object, ByVal e As EventArgs)
        Dim view As GridView = TryCast(sender, GridView)
        edit = view.ActiveEditor
        AddHandler edit.EditValueChanged, AddressOf edit_EditValueChanged
    End Sub

    Private Sub edit_EditValueChanged(ByVal sender As Object, ByVal e As EventArgs)
        gridView1.PostEditor()
    End Sub

    Private Sub gridView1_HiddenEditor(ByVal sender As Object, ByVal e As EventArgs)
        RemoveHandler edit.EditValueChanged, AddressOf edit_EditValueChanged
        edit = Nothing
    End Sub

gridView.CellValueChanged += (sender, e) => {
    GridView view = sender as GridView;
    if (e.Column.FieldName == "Length") {
        double doubleVal = (double)e.Value;
        view.SetRowCellValue(e.RowHandle, "Mark", doubleVal > 10);
    }
};

AddHandler gridView.CellValueChanged, Sub(sender, e)
    Dim view As GridView = TryCast(sender, GridView)
    If e.Column.FieldName = "Length" Then
        Dim doubleVal As Double = CDbl(e.Value)
        view.SetRowCellValue(e.RowHandle, "Mark", doubleVal > 10)
    End If
End Sub

using DevExpress.XtraGrid.Views.Grid;
using DevExpress.XtraEditors.Repository;

// Create a repository item
RepositoryItemProgressBar ieProgress = new RepositoryItemProgressBar();
gridControl1.RepositoryItems.Add(ieProgress);
ieProgress.KeyPress += IeProgress_KeyPress;

// Assign the repository item
colRelevance.ColumnEdit = ieProgress;
// Or
private void GridView1_CustomRowCellEdit(object sender, CustomRowCellEditEventArgs e) {
    if (e.Column == colRelevance) e.RepositoryItem = ieProgress;
}

// Handle + and - key presses
private void IeProgress_KeyPress(object sender, KeyPressEventArgs e) {
    int i = 0;
    if (gridView1.ActiveEditor == null) return;

    if (e.KeyChar == '+') {
        i = (int)gridView1.ActiveEditor.EditValue;
        if (i < 100)
            gridView1.ActiveEditor.EditValue = i + 1;
    }
    if (e.KeyChar == '-') {
        i = (int)gridView1.ActiveEditor.EditValue;
        if (i > 0)
            gridView1.ActiveEditor.EditValue = i - 1;
    }
}

Imports DevExpress.XtraGrid.Views.Grid
Imports DevExpress.XtraEditors.Repository

' Create a repository item
Private ieProgress As New RepositoryItemProgressBar()
gridControl1.RepositoryItems.Add(ieProgress)
Private ieProgress.KeyPress += AddressOf IeProgress_KeyPress

' Assign the repository item
colRelevance.ColumnEdit = ieProgress
' Or
private void GridView1_CustomRowCellEdit(Object sender, CustomRowCellEditEventArgs e)
  If e.Column = colRelevance Then
      e.RepositoryItem = ieProgress
  End If

' Handle + and - keys presses
private void IeProgress_KeyPress(Object sender, KeyPressEventArgs e)
  Dim i As Integer = 0
  If gridView1.ActiveEditor Is Nothing Then
      Return
  End If

  If e.KeyChar = "+"c Then
      i = CInt(Math.Truncate(gridView1.ActiveEditor.EditValue))
      If i < 100 Then
          gridView1.ActiveEditor.EditValue = i + 1
      End If
  End If
  If e.KeyChar = "-"c Then
      i = CInt(Math.Truncate(gridView1.ActiveEditor.EditValue))
      If i > 0 Then
          gridView1.ActiveEditor.EditValue = i - 1
      End If
  End If

    // Create the Commands column editor
    RepositoryItemButtonEdit commandsEdit = new RepositoryItemButtonEdit { AutoHeight = false, Name = "CommandsEdit", TextEditStyle = TextEditStyles.HideTextEditor };
    commandsEdit.Buttons.Clear();
    commandsEdit.Buttons.AddRange(new EditorButton[] {
    new EditorButton(ButtonPredefines.Glyph, "Edit", -1, true, true, false, ImageLocation.MiddleLeft, DemoHelper.GetEditImage()),
    new EditorButton(ButtonPredefines.Glyph, "Delete", -1, true, true, false, ImageLocation.MiddleLeft, DemoHelper.GetDeleteImage())});
    grid.RepositoryItems.Add(commandsEdit);

    // Create an unbound Commands column
    GridColumn _commandsColumn = gridView.Columns.AddField("Commands");
    _commandsColumn.UnboundDataType = typeof(object);
    _commandsColumn.Visible = true;
    _commandsColumn.Width = 100;

    // Hide commandsColumn from EditForm
    _commandsColumn.OptionsEditForm.Visible = DevExpress.Utils.DefaultBoolean.False;

    // Display commands only for the focused row
    gridView.CustomRowCellEdit += (s, e) => {
        if (e.RowHandle == gridView.FocusedRowHandle && e.Column == _commandsColumn)
            e.RepositoryItem = commandsEdit;
    };
    gridView.CustomRowCellEditForEditing += (s, e) => {
        if (e.RowHandle == gridView.FocusedRowHandle && e.Column == _commandsColumn)
            e.RepositoryItem = commandsEdit;
    };

    // Allow only commandsColumn to be edited
    gridView.ShowingEditor += (s, e) => {
        e.Cancel = gridView.FocusedColumn != _commandsColumn;
    };

    gridView.OptionsEditForm.ShowOnDoubleClick = DevExpress.Utils.DefaultBoolean.False;
    gridView.OptionsEditForm.ShowOnEnterKey = DevExpress.Utils.DefaultBoolean.False;
    gridView.OptionsEditForm.ShowOnF2Key = DevExpress.Utils.DefaultBoolean.False;
    gridView.OptionsBehavior.EditingMode = GridEditingMode.EditFormInplace;

    // Perform a specific action when an EditorButton is clicked
    commandsEdit.ButtonClick += (s, e) => {
        switch (e.Button.Caption) {
            case "Edit":
                // Start editing a row using EditForm
                gridView.CloseEditor();
                gridView.ShowEditForm();
                break;
            case "Delete":
                // Delete focused row
                gridView1.DeleteRow(gridView1.FocusedRowHandle);
                break;
        }
    };

    ' Create the Commands column editor
    Dim commandsEdit As RepositoryItemButtonEdit = New RepositoryItemButtonEdit With {.AutoHeight = False, .Name = "CommandsEdit", .TextEditStyle = TextEditStyles.HideTextEditor}
    commandsEdit.Buttons.Clear()
    commandsEdit.Buttons.AddRange(New EditorButton() {
        New EditorButton(ButtonPredefines.Glyph, "Edit", -1, True, True, False, ImageLocation.MiddleLeft, DemoHelper.GetEditImage()),
        New EditorButton(ButtonPredefines.Glyph, "Delete", -1, True, True, False, ImageLocation.MiddleLeft, DemoHelper.GetDeleteImage())
    })
    grid.RepositoryItems.Add(commandsEdit)
    ' Create an unbound Commands column
    Dim _commandsColumn As GridColumn = gridView.Columns.AddField("Commands")
    _commandsColumn.UnboundDataType = GetType(Object)
    _commandsColumn.Visible = True
    _commandsColumn.Width = 100

    ' Hide commandsColumn from EditForm
    _commandsColumn.OptionsEditForm.Visible = DevExpress.Utils.DefaultBoolean.False

    ' Display commands only for focused row
    AddHandler gridView.CustomRowCellEdit, Sub(s, e)
        If e.RowHandle = gridView.FocusedRowHandle AndAlso e.Column Is _commandsColumn Then
            e.RepositoryItem = commandsEdit
        End If
    End Sub
    AddHandler gridView.CustomRowCellEditForEditing, Sub(s, e)
        If e.RowHandle = gridView.FocusedRowHandle AndAlso e.Column Is _commandsColumn Then
            e.RepositoryItem = commandsEdit
        End If
    End Sub

    ' Allow only commandsColumn to be edited
    AddHandler gridView.ShowingEditor, Sub(s, e) e.Cancel = gridView.FocusedColumn <> _commandsColumn

    gridView.OptionsEditForm.ShowOnDoubleClick = DevExpress.Utils.DefaultBoolean.False
    gridView.OptionsEditForm.ShowOnEnterKey = DevExpress.Utils.DefaultBoolean.False
    gridView.OptionsEditForm.ShowOnF2Key = DevExpress.Utils.DefaultBoolean.False
    gridView.OptionsBehavior.EditingMode = GridEditingMode.EditFormInplace

    ' Perform a specific action when an EditorButton is clicked
    AddHandler commandsEdit.ButtonClick, Sub(s, e)
        Select Case e.Button.Caption
            Case "Edit"
                ' Start editing a row using EditForm
                gridView.CloseEditor()
                gridView.ShowEditForm()
            Case "Delete"
                ' Delete focused row
                gridView.DeleteRow(gridView.FocusedRowHandle)
        End Select
    End Sub

RepositoryItemSpinEdit spinEdit = new RepositoryItemSpinEdit();
RepositoryItemCalcEdit calcEdit = new RepositoryItemCalcEdit();
grid.RepositoryItems.Add(spinEdit);
grid.RepositoryItems.Add(calcEdit);
gridView.Columns["Length"].ShowButtonMode = ShowButtonModeEnum.ShowAlways;

// Handle this event to assign editors to individual cells
gridView.CustomRowCellEdit += (sender, e) => {
    GridView view = sender as GridView;
    if (e.Column.FieldName == "Length") {
        bool boolVal = (bool)view.GetRowCellValue(e.RowHandle, "Mark");
        if (boolVal)
            e.RepositoryItem = spinEdit;
        else
            e.RepositoryItem = calcEdit;
    }
};

Dim spinEdit As New RepositoryItemSpinEdit()
Dim calcEdit As New RepositoryItemCalcEdit()
grid.RepositoryItems.Add(spinEdit)
grid.RepositoryItems.Add(calcEdit)
gridView.Columns("Length").ShowButtonMode = ShowButtonModeEnum.ShowAlways

' Handle this event to assign editors to individual cells
AddHandler gridView.CustomRowCellEdit, Sub(sender, e)
    Dim view As GridView = TryCast(sender, GridView)
    If e.Column.FieldName = "Length" Then
        Dim boolVal As Boolean = CBool(view.GetRowCellValue(e.RowHandle, "Mark"))
        If boolVal Then
            e.RepositoryItem = spinEdit
        Else
            e.RepositoryItem = calcEdit
        End If
    End If
End Sub

private void GridView1_ValidatingEditor(object sender, BaseContainerValidateEditorEventArgs e) {
    GridView view = sender as GridView;
    if (view.FocusedColumn == colRequiredDate) {
        DateTime? requiredDate = e.Value as DateTime?;
        DateTime? orderDate = view.GetRowCellValue(view.FocusedRowHandle, colOrderDate) as DateTime?;
        if (requiredDate < orderDate) {
            e.Valid = false;
            e.ErrorText = "Required Date is earlier than the order date";
        }
    }
}

Private Sub GridView1_ValidatingEditor(ByVal sender As Object, ByVal e As BaseContainerValidateEditorEventArgs)
  Dim view As GridView = TryCast(sender, GridView)
  If view.FocusedColumn = colRequiredDate Then
      Dim requiredDate? As Date = CType(e.Value, Date?)
      Dim orderDate? As Date = CType(view.GetRowCellValue(view.FocusedRowHandle, colOrderDate), Date?)
      If requiredDate < orderDate Then
          e.Valid = False
          e.ErrorText = "Required Date is earlier than the order date"
      End If
  End If
End Sub

gridView.ValidatingEditor += (s, e) => {
    string fieldName = string.Empty;
    GridView view = s as GridView;
    EditFormValidateEditorEventArgs ea = e as EditFormValidateEditorEventArgs;
    if(ea == null)
        fieldName = view.FocusedColumn.FieldName;
    else
        fieldName = ea.Column.FieldName;
    int rowCellValue;
    int validatingCellValue = Convert.ToInt32(e.Value);
    if(fieldName == "ID")
        // Iterate through all data rows within GridView
        for(int rowHandle = 0; rowHandle < view.DataRowCount; rowHandle++) {
            // Obtain the ID cell value of the processed row
            rowCellValue = Convert.ToInt32(view.GetRowCellValue(rowHandle, fieldName)); 
            if(rowCellValue == validatingCellValue) {
                e.Valid = false;
                e.ErrorText = "ID should be unique (ValidatingEditor)";
                return;
            }
        }
};

gridView.InvalidValueException += (s, e) => {
    e.ExceptionMode = ExceptionMode.DisplayError;
};

AddHandler gridView.ValidatingEditor, Sub(s, e)
    Dim fieldName As String = String.Empty
    Dim view As GridView = TryCast(s, GridView)
    Dim ea As EditFormValidateEditorEventArgs = TryCast(e, EditFormValidateEditorEventArgs)
    If ea Is Nothing Then
        fieldName = view.FocusedColumn.FieldName
    Else
        fieldName = ea.Column.FieldName
    End If
    Dim rowCellValue As Integer
    Dim validatingCellValue As Integer = Convert.ToInt32(e.Value)
    If fieldName = "ID" Then
        ' Iterate through all data rows within GridView
        For rowHandle As Integer = 0 To view.DataRowCount - 1 
            ' Obtain the ID cell value of the processed row
            rowCellValue = Convert.ToInt32(view.GetRowCellValue(rowHandle, fieldName)) 
            If rowCellValue = validatingCellValue Then
                e.Valid = False
                e.ErrorText = "ID should be unique (ValidatingEditor)"
                Return
            End If
        Next rowHandle
    End If
End Sub

AddHandler gridView.InvalidValueException, Sub(s, e) e.ExceptionMode = ExceptionMode.DisplayError