Error in Toast with null

Question

My code is like this

public Database(Context context) {
    super(context, dbname, null, dbversion);
    try{
      db=getWritableDatabase();
      // TODO Auto-generated constructor stub
      if (db.isOpen()){
        Toast.makeText(null, "Database is open", Toast.LENGTH_LONG).show();
      } else {      
        Toast.makeText(null, "Database is Closed", Toast.LENGTH_LONG).show();
      }
    } catch(Exception e) {
      Log.e(dbname, e.getMessage());        
    }
}

I am getting exception a toast and log cat shows

java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.example.manager/com.example.manager.MainActivity}:
java.lang.NullPointerException: println needs a message

you cant pass null as context, instead of null use getApplicationContext or context or this or classname.this... — Marko Niciforovic, Apr 24 '13 at 14:49

score 2 · Answer 1 · answered Apr 24 '13 at 14:48

2

Instead of

Toast.makeText(null, "Database is open", Toast.LENGTH_LONG).show();

Put :

Toast.makeText(context, "Database is open", Toast.LENGTH_LONG).show();

answered Apr 24 '13 at 14:48

Alexis C.

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Thanks this worked.... But can you please explain me what went wrong and how context solved the problem. – Siva Apr 24 '13 at 14:50
I refer you to this : http://stackoverflow.com/questions/3572463/what-is-context-in-android – Alexis C. Apr 24 '13 at 14:54
Thanks ZouZou I am searching it for quite long time now I got it. – Siva Apr 24 '13 at 14:58

score 1 · Accepted Answer · answered Apr 24 '13 at 14:49

1

Replace this

 Toast.makeText(null, "Database is open", Toast.LENGTH_LONG).show();

to this

 Toast toast = Toast.makeText(context, "Database is open", Toast.LENGTH_LONG);
 toast.show();

answered Apr 24 '13 at 14:49

jimpanzer

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ashishdhiman2007 · Answer 3 · 2013-04-27T05:54:06.957

@siva Toast.makeText has first parameter for Contex(android.content) which can be your created context in the application. Sometimes getApplicationContext(),getBasecontext() is also generally used,second parameter is for String, third parameter is for duration

http://developer.android.com/guide/topics/ui/notifiers/toasts.html

and stackoverflow.com/questions/3572463/what-is-context-in-android as posted by ZouZou

Error in Toast with null

3 Answers3