CODEWITHSUNDEEP
javaandroidxmlandroid-edittextdouble
Robert
Robert

Reputation: 123

How to use EditText value (numberDecimal) in math operations Java

I have a EditText view :

  <EditText
            android:id="@+id/vorgabezeit"
            android:layout_width="50dp"
            android:layout_height="wrap_content"
            android:background="#0277BD"
            android:imeOptions="actionDone"
            android:inputType="numberDecimal"
            android:maxLength="5"
            android:textAlignment="textEnd"
            android:textColor="#ffffff"
            android:textCursorDrawable="@null"
            android:textStyle="bold"
            />

The value entered in this EditText I would like to use it in an math operation. Before I had fixed values :

public void submitOrder(View view) {
     displayPrice((procente / myEditNum) * mitarbeiter);
}

where variables were defined as :

int procente = 120;
int mitarbeiter = 1;

Now, I searched for hours on the web how to take that value entered in EditText and use id further, and this is as close as I got :

public class MainActivity extends AppCompatActivity {
    int procente = 120;
    int mitarbeiter = 1;
    EditText myEdit = (EditText) findViewById(R.id.vorgabezeit);
    String myEditValue = myEdit.getText().toString();
    double myEditNum = Double.parseDouble(myEditValue);

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

    public void submitOrder(View view) {
        displayPrice((procente / myEditNum) * mitarbeiter);
    }
}

The application crashes from the start. Thank you for your patience and help.

Best regards, Robert

Upvotes: 0

Views: 971

Answers (3)

Juan Hurtado
Juan Hurtado

Reputation: 368

Make sure you add android:inputType="number" to your EditText on the xml to ensure the user can ONLY type numbers on it, then :

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

        findViewById(R.id.button)
                .setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        displayPrice((procente / Double.parseDouble(((EditText) findViewById(R.id.vorgabezeit))
                                .getText().toString())) * mitarbeiter);
                    }
                });
    }

btw your code crashes because you called findviewById before setting the content view to the activity so basically it searches on a non-existing layout and your edit text and button become null because of it

Upvotes: 0

cyroxis
cyroxis

Reputation: 3711

First you need to post the LogCat when you are having a crash.

Second You can not call findViewById until after setContentView is called. You should to initialize your edit text in onCreate. 

// Initialize values in onCreate after setContentView
EditText myEdit;
String myEditValue;
double myEditNum;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    myEdit = (EditText) findViewById(R.id.vorgabezeit);
    myEditValue = myEdit.getText().toString();
    myEditNum = Double.parseDouble(myEditValue);
}

Upvotes: 1

Rudziankoŭ
Rudziankoŭ

Reputation: 11251

What about getText(). I added button, since you have to get text after some user action, not right after onCreate event.

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

    mButton = (Button)findViewById(R.id.button);
    mEdit   = (EditText)findViewById(R.id.vorgabezeit);

    mButton.setOnClickListener(
        new View.OnClickListener()
        {
            public void onClick(View view)
            {
                Log.v("EditText", mEdit.getText().toString());
            }
        });
}

Upvotes: 0

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