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The DockPositionChanged event occurs when postbacks are enabled and the user changes the position of a RadDock control. This change can be

  • A move from one RadDockZone control to another.

  • A move from a RadDockZone control to a floating position.

  • A move from a floating position to a RadDockZone control.

  • A change of index within a RadDockZone control.

The DockPositionChanged event does not occur when the RadDock control is moved from one floating position to another, or when the RadDock control is moved programmatically.

The DockPositionChanged event handler receives two arguments:

  1. The RadDock control whose position has changed.

  2. A DockPositionChangedEventArgs object. This object has two properties describe the new position of the RadDock object:

    • DockZoneID is the ID of the new RadDockZone to which the control is moved. If the RadDock control is moved to a floating position, DockZoneID is null.
    • Index is the new index of the RadDock control in the RadDockZone identified by DockZoneID. If the RadDock control is moved to a floating position, Index is -1.
    • IsDragged determines whether the position of the RadDock control is changed as a result of dragging. If the position of the dock control is changed because another one is closed or moved out of the RadDockZone, IsDragged will be set to false.

In the DockPositionChanged event handler, the DockZoneID and Index properties of the RadDock control reflect the old position from which the RadDock control is being moved. This is true even if the event handler is called after a delay because the value of the AutoPostBack property is False.

The DockPositionChanged event is fired early in the page lifecycle (you can find more details in the Lifecycle article). This means that not all controls are completely updated. For example, the number of docks in the respective dock zones will be the old one from Page_Init and will not reflect the change in position yet. You can access the updated Controls collection in later events (such as Page_Load or postback events).

Use a DockPositionChanged event handler to respond when the user moves the RadDock control:

protected void RadDock1_DockPositionChanged(object sender, DockPositionChangedEventArgs e)
    RadDock dock = (RadDock)sender;
    if (e.DockZoneID == String.Empty)
        dock.Text = String.Format("I used to be in {0} but now I am floating.", dock.DockZoneID);
        if (dock.DockZoneID == String.Empty)
            dock.Text = "I used to be floating, but now I am docked in " + e.DockZoneID;
        else if (dock.DockZoneID != e.DockZoneID)
            dock.Text = String.Format("I moved from {0} to {1}.", dock.DockZoneID, e.DockZoneID);
            dock.Text = String.Format("I moved from position {0} to position {1}." + dock.Index.ToString(), e.Index.ToString());
Protected Sub RadDock1_DockPositionChanged(ByVal sender As Object, _
                          ByVal e As DockPositionChangedEventArgs) _
                          Handles RadDock1.DockPositionChanged
    Dim dock As RadDock = DirectCast(sender, RadDock)
    If e.DockZoneID = [String].Empty Then
        dock.Text = [String].Format("I used to be in {0} but now I am floating.", _
        If dock.DockZoneID = [String].Empty Then
            dock.Text = "I used to be floating, but now I am docked in " + _
        ElseIf dock.DockZoneID <> e.DockZoneID Then
            dock.Text = [String].Format("I moved from {0} to {1}.", _
                                        dock.DockZoneID, e.DockZoneID)
            dock.Text = [String].Format("I moved from position {0} to position {1}.", _
                                         dock.Index.ToString(), e.Index.ToString())
        End If
    End If
End Sub

See Also

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