How to set a button visible from another activity in android

Question

I have a very simple problem. I have a invisible button in my Main Activity, and I have a second Activity that makes that button visible. In the second activity I don´t have a p

Answer 1

Try this code in onResume() of your MainActivity:

 try {
     if(getIntent().getExtras().containsKey("your_parameter")) {
         btn.setVisibility(View.VISIBLE);
     }
 } catch(Exception e){
     //...
 }

In second Activity put "your_parameter" parameter as extra to Intent only if you want to make that button visible.