Windows Forms FAQ resources

5. Windows Forms Datagrid

5.21 How do I programmatically determine the selected rows in a datagrid?

The method DataGrid.IsSelected can tell you if a particular row is selected. So, you could use IsSelected in a loop through all your rows to finds if multiple rows have been selected. Depending upon the size of your datagrid, this may be a viable solution. If not, you could track the selections yourself by monitoring the key actions and the mouse actions. This would be more work. Thanks to John Hughes to the suggestion to use the dataview.

[C#]

public ArrayList GetSelectedRows(DataGrid dg)

{

ArrayList al = new ArrayList();

CurrencyManager cm = (CurrencyManager)this.BindingContext[dg.DataSource, dg.DataMember];

DataView dv = (DataView)cm.List;

for(int i = 0; i < dv.Count; ++i)

{

if(dg.IsSelected(i))

al.Add(i);

}

return al;

}

private void button1_Click(object sender, System.EventArgs e)

{

string s = "Selected rows:";

foreach(object o in GetSelectedRows(dataGrid1))

{

s+=""+o.ToString();

}

MessageBox.Show(s);

}

[VB.NET]

Public Function GetSelectedRows(ByVal dg As DataGrid) As System.Collections.ArrayList

Dim al As New ArrayList()

Dim cm As CurrencyManager = Me.BindingContext(dg.DataSource, dg.DataMember)

Dim dv As DataView = CType(cm.List, DataView)

Dim i As Integer

For i = 0 to dv.Count - 1

If dg.IsSelected(i) Then

al.Add(i)

End If

End Next

Return al

End Function 'GetSelectedRows

Private Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim s As String = "Selected rows:"

Dim o As Object

For Each o In GetSelectedRows(dataGrid1)

s += " " + o.ToString()

Next o

MessageBox.Show(s)

End Sub 'button1_Click