I have developed a WinForms application in C# that can make any window “top most” by selecting it from drop down list and toggle a checkbox.
But having an app open for that seems a bit silly, so I was wondering if it is possible to add an entry to the top left icon in Windows that runs a program of my choice?
I don’t have any experimental code because I don’t know what that icon/spot is called, therefor I can’t research it.
This area of a winform is called the “Non client area”.
But I think the simplest solution, if your goal is to add your switch to all external winforms, is to create process that will place a little form with your on/off switch at the top left of the active window form. You can try to put it directly on the external form, but you will have problems with position priorities.
Since you included “WinApi” in your question, I guess you are able to get the window handle, coordinates and topmost property of the current running processes.