To add a C1DockingTab to your form, complete the following basic operations:

1. Place the C1CommandDock control onto your form using a drag-and-drop operation.
2. The C1CommandDock will dock to the left side of the form. Select the drop-down arrow in the C1CommandDock.Dock property and click the top rectangle. This will dock the C1CommandDock control to the top of the form.
3. Place the C1DockingTab control inside the C1CommandDock control using a drag-and-drop operation. It will appear like this on your form:
   
   
4. Build and run the application. Select Page1 with your mouse and drag it downward. Your docking tab at run time should look like the following docking tab:
   
   

Set Centre Tab Width

In C1CommandDock, the floating tabpages can be docked using Left, Top, Right, Bottom, and Diamond anchors. When docking the tabpages in the container, existing tabs may become hidden due to the space occupied by the new tab. In such scenarios, C1CommandDock allows you to set a minimum tab size for existing tabs through CentralTabMinimumSize property available in C1CommandDock class. The CentralTabMinimumSize accepts a non-negative value, either as a percentage or an absolute value. The percentage value specifies the minimum space reserved for the existing tabs as a proportion of the parent container, whereas absolute value specifies the space in terms of pixels.

The image below illustrates how the CentralTabMinimumSize property preserves space for the existing tabs in C1CommandDock while new tab is being docked.

The below code snippet illustrates setting the CentralTabMinimumSize property with value 150px for central tabs in C1CommandDock.

c1CommandDock1.CentralTabMinimumSize.WidthType = SizeType.Absolute;
c1CommandDock1.CentralTabMinimumSize.Width = 150;