Question

I am working on a Testing Project for me , just so I could learn more , so now I need to update the text of a TextView constantly every 250 milliseconds through a for(;;) loop , it happens after a Button click … My problem is that whenever I press that button my app freezes (Yes my button is totally working , verified through previous testings) , I am using a handler to the Main thread doesn’t get affected while the Runnable is up … Here is my code of the Button and Handler …

final Handler handler = new Handler();
        B3.setOnClickListener(new View.OnClickListener() {


            @Override
            public void onClick(View v) {

                handler.post(new Runnable() {

                    @Override
                    public void run() {
                        // TODO Auto-generated method stub
                        for(;;){
                            String a = Shells.sendSingleCommand("free");//Here I send a command "free" and it returns its output 
                            text.setText(a);//text is my TextView which is used through my experimentations ... 
                            synchronized(this){
                                try{
                                    wait(250);
                                }catch(Exception e){

                                }
                        }

                        }
                    }
                });
                }

        });

If you need anymore info ask please 🙂

Answer 1

use handler.postDelayed for updating textview constantly every 250 milliseconds instead of using for loop to avoid freeze current Activity as :

Handler handler=new Handler();
B3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                  handler.post(runnable);  
                }

        });
Runnable runnable=new Runnable(){  
  @Override  
    public void run() {  
       String a = Shells.sendSingleCommand("free");
       text.setText(a);
       handler.postDelayed(runnable, 250);  
     }  
 };