CODEWITHSUNDEEP
android
Adi
Adi

Reputation: 465

Unfortunately android app has stopped

I am doing a simple program for addition of two numbers which are input from EditText. But when user clicks the button 'Click to Add' leaving the fields empty, program exits saying 'Unfortunately, program has stopped.'

Here is the code:

public class MainActivity extends Activity {

long a, b, sum;
Button add, clr;
EditText e1, e2, res;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    add = (Button) findViewById(R.id.bAdd);
    add.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) throws NumberFormatException {
            // TODO Auto-generated method stub

                e1 = (EditText) findViewById(R.id.tv1);         
                String str1 = e1.getText().toString();

                e2 = (EditText) findViewById(R.id.tv2);
                String str2 = e2.getText().toString();

                try{
                    a = Integer.parseInt(str1);
                    b = Integer.parseInt(str2);
                }catch(NumberFormatException e){
                    res.setText("Please enter valid entries");
                }

                sum = a + b;    

                res = (EditText) findViewById(R.id.result);
                res.setText("Your sum is " + sum);
        }
    });

    clr = (Button) findViewById(R.id.bClr);
    clr.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) throws NumberFormatException {
            // TODO Auto-generated method stub
            e1.setText("");
            e2.setText("");
            res.setText("");
        }
    });
}

}

I want the app to respond 'Please enter valid entries' for blank EditText entries.

Upvotes: 1

Views: 1822

Answers (4)

CocoNess
CocoNess

Reputation: 4222

Your line: 

res = (EditText) findViewById(R.id.result);

must be moved so that your res variable is initialized before you use res.setText. It's not initialized in your catch statement. Move it to the position indicated below. You can initialise it when you do your other findViewById

e1 = (EditText) findViewById(R.id.tv1); 
e2 = (EditText) findViewById(R.id.tv2);
res = (EditText) findViewById(R.id.result);

Upvotes: 1

Nargis
Nargis

Reputation: 4787

Instead of catching NumberFormatException you can just catch any Exception in try catch block .Please post the Log Cat Error you are getting.

Upvotes: 0

MysticMagicϡ
MysticMagicϡ

Reputation: 28823

Yes.

Add these lines.

if (e1.getText().toString() == null || e2.getText().toString() == null)
{
       //Show dialog
}
else
{
    String str1 = e1.getText().toString();
    String str2 = e2.getText().toString();
    try{
                        a = Integer.parseInt(str1);
                        b = Integer.parseInt(str2);
                    }catch(NumberFormatException e){
                        res.setText("Please enter valid entries");
                    }

                    sum = a + b;    

                    res = (EditText) findViewById(R.id.result);
                    res.setText("Your sum is " + sum);
    }
}

And tutorial for any help on alert dialog

Upvotes: 0

Nermeen
Nermeen

Reputation: 15973

because you are getting a null text from the edit texts..so check for null first

@Override
    public void onClick(View v) throws NumberFormatException {
        // TODO Auto-generated method stub

            e1 = (EditText) findViewById(R.id.tv1); 
            e2 = (EditText) findViewById(R.id.tv2);

            if( e1.getText() != null && e2.getText() != null) { 

            String str1 = e1.getText().toString();


            String str2 = e2.getText().toString();

            try{
                a = Integer.parseInt(str1);
                b = Integer.parseInt(str2);
            }catch(NumberFormatException e){
                res.setText("Please enter valid entries");
            }

            sum = a + b;    

            res = (EditText) findViewById(R.id.result);
            res.setText("Your sum is " + sum);
           }
    }

Upvotes: 1

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