In VS 2015, you can also achieve this by clicking on the collapse icon and then clicking on the XAML icon, it will first display the constructor, only then it will show only the xaml code and save the structure to collapse just in case it is needed.
Click collapse icon (double arrows) 
Click the XAML icon (XAML with a code sign) 
Here's how it should look after clicking the XAML icon

Finally, you can Save window layout in the window menu and use the layout the next time you open your project.
Ashraf Abusada Jun 29 '16 at 0:44 2016-06-29 00:44
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