本示例展示了如何防止“ContactName”列被拖动到 “自定义”窗体。

为了控制网格列的拖动和放落，我们接管了 GridView.DragObjectOver 事件。 此事件的 DragObjectOverEventArgs.DropInfo 参数包含了关于当前位置的信息，在该位置上如果最终用户放落被拖动对象，则发生拖动和放落。 当拖动经过“自定义”窗体上面时 DragObjectOverEventArgs.DropInfo 的 Index 属性值为 -1。

C#CopyCode image复制代码
using DevExpress.XtraGrid.Views.Base;

private void bandedGridView1_DragObjectOver(object sender, DragObjectOverEventArgs e) {
    GridColumn column = e.DragObject as GridColumn;
    if (column != null) {
        e.DropInfo.Valid = !(e.DropInfo.Index == -1 && column.FieldName == "ContactName");
    }
}
Visual BasicCopyCode image复制代码
Imports DevExpress.XtraGrid.Views.Base

Private Sub BandedGridView1_DragObjectOver(ByVal sender As Object, _
  ByVal e As DragObjectOverEventArgs) Handles BandedGridView1.DragObjectOver
    If TypeOf e.DragObject Is GridColumn Then
        Dim column As GridColumn = CType(e.DragObject, GridColumn)        
        e.DropInfo.Valid = Not (e.DropInfo.Index = -1 And column.FieldName = "ContactName")
    End If
End Sub