using MacBook Pro Retina, OS High Sierra, screen shots do not appear on desk top?

I went back to terminal and typed in "defaults write com.apple.screencapture location ~/Desktop". After doing that I restarted my computer and screenshots started appearing directly on my desktop

I can't say. I don't deliberately use drop box. At first I tried using finder without luck. Then I tried finder again and typed in "screen" and the screen shots appeared on a list with items with the word screen in the title. It did not say where they were residing. When I clicked on them they appear on the desk top. I never had to do this before. How can I avoid this nuisance step?

This did not work. In fact I could no longer find the screen shots until I went back to terminal and typed in "defaults write com.apple.screencapture location ~/Desktop". After doing that I am back to having to go to finder type in screen, finding it on list of items that pop up, click on the the screen shot item and then it will appear on the desktop. But I cannot get screenshot to appear on desktop directly. This did not solve my problem. I am not saying you are not helpful. I may not have followed the directions properly. I just don't know.

I followed your directions. I got an Apple directions "How to Change Your Mac's Default Screenshot Directory. I followed those directions to the point where it said enter. Below is what appeared. I then tried another screen shot and no luck. In fact when I tried to covert the below screen hot into a PDF to attach here, it did not appear on my desktop. I had to go to finder to find it. Then click on it in finder, and then it popped up on desktop. BTW I don't know what to do with the new folder that was created by following the directions.