How to remove the close button in DockingManager?

In DockingManager, you can customize the Close button appearance using the following options.

By using “CloseEnabled” property.
By removing Close button from CaptionButtonCollection

The following code example demonstrates the same.

//Option 1
private void SetCaptionBtnOptions()
{
//Hide the CloseButton for all the Controls that are DockEnabled.
for (int i = 0; i < this._dockingMgr.CaptionButtons.Count; i++)
{
if (this._dockingMgr.CaptionButtons[i].Name == "CloseButton")
{
this._dockingMgr.CaptionButtons.RemoveAt(i);
}
}
}
//Option 2
//Hide the CloseButton for all the Controls that are DockEnabled
this.dockingManager1.CloseEnabled = false;

'Option 1
Private Sub SetCaptionBtnOptions()
'Hide the CloseButton for all the Controls that are DockEnabled.
Dim i As Integer = 0
Do While i < Me.dockingManager1.CaptionButtons.Count
If Me.dockingManager1.CaptionButtons(i).Name = "CloseButton" Then
Me.dockingManager1.CaptionButtons.RemoveAt(i)
End If
i += 1
Loop
End Sub
'Option 2
'Hide the CloseButton for all the Controls that are DockEnabled.
this.dockingManager1.CloseEnabled = false;

The following screenshots illustrates the output.

Showing after remove close button in floating control