[[Property:title|Hello World!]]
[[Property:weight|-4]]
[[Property:uuid|37b82651-78e9-dd6a-97bf-0fe3c444157d]]
[[Image:hello|hello]]  <br/>
<br/>

==Compiling==

To compile the example: 
* Launch EiffelStudio. 
* Click '''Add project'''
* Browse to ''$ISE_EIFFEL\examples\wel\hello\''. 
* Choose ''hello.ecf''
* Choose the location where the project will be compiled, by default the same directory containing the configuration file. 
* Click '''OK'''. 

==Running==

After you launch the sample, You should see a window displayed as illustrated above. You will have full control over the window, and the program will quit when you close the window. 

==Under the Hood==

MAIN_WINDOW inherits WEL_FRAME_WINDOW. In this example, we have redefined on_paint as shown below:
<code>
    on_paint (paint_dc: WEL_PAINT_DC; invalid_rect: WEL_RECT)
            --Draw a centered text 
        do
            paint_dc.draw_centered_text("Hello, World!", client_rect)   
        end 
</code>

{{note|If you look at MAIN_WINDOW, you will see that it contains many features. However, nearly all of these are features are inherited from WEL_FRAME_WINDOW. }}

This sample contains the following classes: 
* HELLO_DEMO
* MAIN_WINDOW


{{seealso|<br/>
[[Tutorial Step 3|Tutorial Step3]]  <br/>
[[Common message hooks|Common message hooks]]  }}