Copy/Paste DisplayMember for GridViewComboBoxColumn

Product Version	Product	Author	Last modified
Q2 2014	RadGridView for WinForms	Desislava Yordanova	August 22, 2014

Problem

By default, the RadGridView built-in copy/paste functionality uses the selected cells’ value when storing data in the Clipboard. However, when you have a GridViewComboBoxColumn it is more suitable to copy/paste the cells’ text.

Solution

MasterGridViewTemplateintroduces two methods appropriate for customizing the Clipboard data: Copyand Paste.

To achieve the desired functionality you should create a derivative of the MasterGridViewTemplateand override its Copy method, where the Clipboard content can be modified:

• C#
• VB.NET

public class CustomMasterGridViewTemplate : MasterGridViewTemplate
{
    public override void Copy()
    {
        base.Copy();
        if (Clipboard.ContainsData(DataFormats.Text)) {
            string data = Clipboard.GetData(DataFormats.Text).ToString();
            if (data != string.Empty) {
                StringBuilder sb = new StringBuilder();
                //modify the copied data and replace it in the clipboard
                foreach (GridViewRowInfo row in this.Owner.SelectedRows) {
                    int i = 0;
                    while (i < row.Cells.Count) {
                        if (i > 0) {
                            sb.Append(";");
                        }
                        string cellText = null;
                        GridViewComboBoxColumn comboCol = row.Cells(i).ColumnInfo as GridViewComboBoxColumn;
                        if (comboCol != null) {
                            //copy the DisplayMember
                            cellText = comboCol.GetLookupValue(row.Cells(i).Value);
                        } else {
                            cellText = row.Cells(i).Value + string.Empty;
                        }
                        sb.Append(cellText);
                        i += 1;
                    }
                    sb.AppendLine();
                }
                Clipboard.SetData(DataFormats.Text, sb.ToString());
            }
        }
    }
}

Public Class CustomMasterGridViewTemplate
Inherits MasterGridViewTemplate
    Public Overrides Sub Copy()
        MyBase.Copy()
        If Clipboard.ContainsData(DataFormats.Text) Then
            Dim data As String = Clipboard.GetData(DataFormats.Text).ToString()
            If data <> String.Empty Then
                Dim sb As New StringBuilder()
                'modify the copied data and replace it in the clipboard
                For Each row As GridViewRowInfo In Me.Owner.SelectedRows
                    Dim i As Integer = 0
                    While i < row.Cells.Count
                        If i > 0 Then
                            sb.Append(";")
                        End If
                        Dim cellText As String
                        Dim comboCol As GridViewComboBoxColumn = TryCast(row.Cells(i).ColumnInfo, GridViewComboBoxColumn)
                        If comboCol IsNot Nothing Then
                            'copy the DisplayMember
                            cellText = comboCol.GetLookupValue(row.Cells(i).Value)
                        Else
                            cellText = row.Cells(i).Value & String.Empty
                        End If

                        sb.Append(cellText)
                        i += 1
                    End While
                    sb.AppendLine()
                Next
                Clipboard.SetData(DataFormats.Text, sb.ToString())
            End If
        End If
    End Sub
End Class

Overriding the Paste method allows you to convert the Clipboard data to format appropriate for RadGridView. Thus, copying the above data from Notepad and pasting it to RadGridView can be achieved.

• C#
• VB.NET

public override void Paste()
{
    if (Clipboard.ContainsData(DataFormats.Text))
    {
        string data = Clipboard.GetData(DataFormats.Text).ToString();
        if (data != string.Empty)
        {
            StringBuilder sb = new StringBuilder();
            string[] rowTokens = data.Split(new string[] { Environment.NewLine.ToString() }, StringSplitOptions.RemoveEmptyEntries);
            foreach (string rowToken in rowTokens)
            {
                string[] tokens = rowToken.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries);

                for (int i = 0; i < tokens.Length; i++)
                {
                    GridViewComboBoxColumn comboColumn = this.Owner.Columns[i] as GridViewComboBoxColumn;
                    if (i < this.Owner.Columns.Count && comboColumn != null)
                    {
                        //get the ValueMember
                        sb.Append(GetValueMember(tokens[i], comboColumn.DataSource));
                    }
                    else
                    {
                        sb.Append(tokens[i]);
                    }

                    if (i < tokens.Length - 1)
                    {
                        sb.Append("\t");
                    }
                }
                sb.Append(Environment.NewLine.ToString());
            }

            Clipboard.SetData(DataFormats.Text, sb.ToString());
        }
    }

    base.Paste();
}

private string GetValueMember(string token, object source)
{
    IEnumerable<Country> dataSource = source as IEnumerable<Country>;
    if (dataSource != null)
    {
        foreach (Country c in dataSource)
        {
            if (c.Name == token)
            {
                return c.ID.ToString();
            }
        }
    }

    return string.Empty;
}

Public Overrides Sub Paste()
    If Clipboard.ContainsData(DataFormats.Text) Then
        Dim data As String = Clipboard.GetData(DataFormats.Text).ToString()
        If data <> String.Empty Then
            Dim sb As New StringBuilder()
            Dim rowTokens As String() = data.Split(New String() {Environment.NewLine.ToString()}, StringSplitOptions.RemoveEmptyEntries)
            For Each rowToken As String In rowTokens
                Dim tokens As String() = rowToken.Split(New Char() {";"c}, StringSplitOptions.RemoveEmptyEntries)

                For i As Integer = 0 To tokens.Length - 1
                    Dim comboColumn As GridViewComboBoxColumn = TryCast(Me.Owner.Columns(i), GridViewComboBoxColumn)
                    If i < Me.Owner.Columns.Count AndAlso comboColumn IsNot Nothing Then
                        'get the ValueMember
                        sb.Append(GetValueMember(tokens(i), comboColumn.DataSource))
                    Else
                        sb.Append(tokens(i))
                    End If

                    If i < tokens.Length - 1 Then
                        sb.Append(vbTab)
                    End If
                Next
                sb.Append(Environment.NewLine.ToString())
            Next

            Clipboard.SetData(DataFormats.Text, sb.ToString())
        End If
    End If

    MyBase.Paste()
End Sub

Private Function GetValueMember(token As String, source As Object) As String
    Dim dataSource As IEnumerable(Of Country) = TryCast(source, IEnumerable(Of Country))
    If dataSource IsNot Nothing Then
        For Each c As Country In dataSource
            If c.Name = token Then
                Return c.ID.ToString()
            End If
        Next
    End If

    Return String.Empty
End Function

The last step we need to do is to replace the default MasterGridViewTemplate with the custom one:

• C#
• VB.NET

public class CustomGrid : RadGridView
  {
      protected override RadGridViewElement CreateGridViewElement()
      {
          return new CustomRadGridViewElement();
      }

      public override string ThemeClassName
      {
          get
          {
              return typeof(RadGridView).FullName;
          }
      }
  }

  public class CustomRadGridViewElement : RadGridViewElement
  {
      protected override MasterGridViewTemplate CreateTemplate()
      {
          return new CustomMasterGridViewTemplate();
      }

      protected override Type ThemeEffectiveType   
      {
          get  
          {
              return typeof(RadGridViewElement);   
          }
      }
  }

Public Class CustomGrid
Inherits RadGridView
    Protected Overrides Function CreateGridViewElement() As RadGridViewElement
        Return New CustomRadGridViewElement()
    End Function

    Public Overrides Property ThemeClassName As String
        Get
            Return GetType(RadGridView).FullName
        End Get
        Set(value As String)
            MyBase.ThemeClassName = value
        End Set
    End Property
End Class

Public Class CustomRadGridViewElement
Inherits RadGridViewElement
    Protected Overrides Function CreateTemplate() As MasterGridViewTemplate
        Return New CustomMasterGridViewTemplate()
    End Function

    Protected Overrides ReadOnly Property ThemeEffectiveType() As Type
        Get
            Return GetType(RadGridViewElement)
        End Get
    End Property
End Class

Clipboard.SetData method gives you the possibility to specify the format of the data to be set. You can customize not only DataFormats.Text, demonstrated above, but DataFormats.CommaSeparatedValue and DataFormats.Html as well, following the same approach.

A complete solution in C# and VB.NET can be found here.