I continue my debug on android, and about the LogCat window named "Android Device Logging", I did not succeed in making it work, but I remarked something which could explain this problem : When you active the DDMS (Android Device Monitor), you can see the LogCat traces in the LogCat part of this application, but I remarked that this application intercept all the LogCat traces even when it was not "launched" ! I think this application is always active (or one of its service), so I think it could be this application / service which catch all LogCat traces and so we can not see them in the other window... Do you think it can be an explaination ?
You could reply me to use the DDMS to see traces... OK but there is another problem since when you launch an android debug session withe the DDMS "on", the debugger can not connect to the application !
And for all other programers, I remarked another small issue : if you put any "special character" in a CCLOG traces call (like in french 'à'), , the trace won't appear in LogCat window !
So in conlusion, I think LogCat is actually not very user friendly with VS 2015 !