How to do a number keypad in java

Question

I trying to figure out how to do a number keypad in java. I'm recently started using java, still have so much to learn. The following is what I came up with so far but it only returns one char at a time. Still researching this, but would really appreciate any assistance..thanks

currentButton = (JButton)event.getSource();
itemQuantity = currentButton.getText().charAt(0) - '0';

Are you trying to create a virtual keyboard on screen for just numbers or are you trying to read key presses on the number pad of a real keyboard? — pimaster, Nov 07 '12 at 01:39

score 3 · Answer 1 · answered Nov 07 '12 at 01:45

3

Your question is a bit vague to me.

I hope Integer.parseInt("string") and/or Double.parseDouble("string") work for you.

answered Nov 07 '12 at 01:45

user1804740

41
2

Also consider `Integer.valueOf()`. – trashgod Nov 07 '12 at 02:22

score 3 · Accepted Answer · answered Nov 07 '12 at 02:20

It looks like you're using the button's text as the value of one digit in a number representing itemQuantity. Each time a button is pressed, you should append that button's digit to a string:

String currentString = "";
currentString += currentButton.getText();

Then you can get the numeric value as @user1804740 suggests:

itemQuantity = Integer.parseInt(currentString);

Note, you'll have to handle any NumberFormatException thrown by the conversion.

Also consider `StringBuilder` for `currentString`. – trashgod Nov 07 '12 at 05:21 — trashgod, Nov 07 '12 at 05:21

How to do a number keypad in java

2 Answers2