How to display the value of a variable on the screen?

I know this is very basic question, but I need to know, how I can display the contents of a variable on the screen.

Do I use a textview in my layout?

I have a textview box and I can set it to say something in the editor but I need to write the contents of a var开发者_如何学运维iable so I can do some error checking.

Anyone help?

If you have a TextView named textViewName defined in your layout XML file, you can just do something like this in your Activity class:

setContentView(R.layout.layoutName);
TextView textView = (TextView) findViewById(R.id.textViewName);
textView.setText("text you want to display");

Is this what you're looking for? If you don't need to display it to the screen, and just want to debug, just use Log() and logcat to view the messages.

If you have a list on the screen , then to not lose the list and still show change use , taking @Matt's example.

TextView textView = (TextView) findViewById(R.id.textViewName);
textView.setText("text you want to display");

It worked for me.

In the Activity...

  public void onCreate(Bundle savedInstanceState)
  {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    int myValue = deriveMyValue();
    String message =
        myValue == -1 ?
            "The value is invalid." :
            "The value is " + myValue;
    TextView tv = (TextView) findViewById(R.id.my_text_view);
    tv.setText(message);
  }

int count=7;
     TextView tv = (TextView) findViewById(R.id.my_text_view);
tv.setText("you have entered"+count+"as the integer");

As you can see,you can include other data types like integers also in the setText block

In addition, if you want to concatenate a string and a variable, you can use the "+" operator as you would do in System.out.print