I need to configure a button with a code that takes the first two digits of a number (when clicked) (from a textbox) and adds a number to it; and then takes the 3rd and 4th digits and does somewhat the same to it and displays the result value in a toast message. The user inputs the original number to which the additions and subtractions must be done.
So far I have only done: Toast.makeText(TimerCodeActivity.this, String.valueOf(
After that I am just lost
Try something like the following:
EditText theTextBox = (EditText)findViewById(R.id.idOfTheEditText);
int digits = Integer.parseInt(theTextBox.getText().toString().subString(0,2)); // Take the first two digits
int newnumber = digits + 4; // Add a number? Or are you trying to add like a string?
Toast.makeText(TimerCodeActivity.this, String.valueOf(newnumber), Toast.LENGTH_LONG).show();
Related
I want the user to type in his or her Facebook account-link (don't have a better solution atm).
Now, when the user clicks the edittext it is supposed to say : "www.facebook.com/". Now the cursor is supposed to be at the END of the edittext (after the "/") and the user is not supposed to delete the first letters so that the "www.facebook.com/" stays exactly where it is. This will have the user to ONLY type in his or her facebook name and therefore connect the profile.
Is there a way of doing this?
Thank you :)
You can do that by using the event "TextChanged" and in your code validate if the size is big than your string, like that:
if (((EditText)sender).Text.Length >= 17)
{
((EditText)sender).Text = e.NewTextValue;
}
else
{
((EditText)sender).Text = "www.facebook.com/";
}
So if the value is bigger than your string you will replace that for the value, if not you just set the value with your string
as getting into android i decided to replace the default calculator with mine. A simple calculator with the 4 operational signs. I've been giving to all buttons the right behaviour, storing every number in a 'num' ArrayList(String) and signs in a 'sign' ArrayList(String).
What i wanted to do, was to then combine numbers and signs into a string, parse it into a float and getting a result. I thought this was one of the easy/simple ways to deal with it, since when you set a float like this:
float f = 6*4-5/2+3
it gives you the right result. but it clearly does not when starting from a String, like this:
String s = "6*4-5/2+3"
Float f = Float.valueOf(s)
Is there a way to getting a result from my 2 ArrayList(String)? In the negative case, what would be a doable approach (in the sense im not an experienced programmer)I?
I Think this approach is incorrect.
I would do the following:
You would have a Textview or Edittext as the calculator "screen" on top.
then you would have all your number and operation signs buttons.
Now, every number you press, it will append to the last one on the screen, using .append()
once you tap on an operator sign - two things will happen:
1) the number in the textView will be stored as a Float (using Float.valueOf(yourTextView); in a varibale, say firstNum.
2) you will save the operator you clicked in a second variable, say String calcOper.
Now, you enter your second number, and then you would press the Equals sign.
What will happen then is simply use a Switch of If expression.
If calcOper is "-" - then do firstNum- Current number shown on screen.
If calcOper is "+" - then do firstNum+ Current number shown on screen.
At last don't forget to set the text on the TextView the result.
Good luck!
I am now working on a calculator, and everything works fine except for decimal places.
The calculator contains 2 displays actually, one is called fakedisplay for actual operations, and one is called Display, for presenting the desired format, ie adding commas.
When pressing 12345.678, Display will follow fakedisplay and present as 12,345.678, but if i press 12345.009, the fakedisplay will work normally as 12345.009, but the Display stuck as 12,345 until 9 is pressed, and at that time it will show 12,345.009 normally.
However, it is strange that when the user presses 0, there is no response, and until pressing 9, 009 will then immediately append.
I know this arise from the parsing code, but based on this, how could I amend the following code? I really cannot think of any solution... Many thanks for all your advice!
one.setOnClickListener(new View.OnClickListener() {
if (str.length()<15) {
Fakedisplay.append("1");
}
DecimalFormat myFormatter1 = new DecimalFormat("###,###,###,###.#################");
String str1=Fakedisplay.getText().toString();
String stripped1 = Double.valueOf(str1).toString();
stripped1 = myFormatter1.format(Double.valueOf(stripped1));
if (stripped1.endsWith(".0"))
stripped1 = stripped1.substring(0, stripped1.length() - 2);
Display.setText(stripped1);
}
Probably the easiest solution is to not strip off the .0 in the code for every keystroke..
Instead, only strip off trailing zeros (assuming there's a decimal point in there of course) when the user calls for a result. Entering keys such as the digit keys 0 through 9, the decimal point ., or the sign-change key +/- (what I'll call the entry keys) are not generating a result so should not strip trailing zeros.
However, non-entry keys, such as when you press + or - or = on your calculator can freely modify the number.
That will give you a display of the digits being entered as the user enters them but will still strip off trailing zeros when necessary.
You can do that with a modification to your statement (and, as mentioned, only doing this when the user presses a non-entry key):
stripped1 = stripped1.replaceAll("(\\.[0-9]*[1-9])0+$","$1");
stripped1 = stripped1.replaceAll("\\.0$","");
The first statement removes all trailing zeros at the end of a decimal number (other than on if it's really an integer). The second takes care of that case.
No doubt I could make a single substitution if I gave it some more thought but that should be enough to get it functional.
i have an edit text in my activity.i am entering numbers in it manually but
int mystart = destinationNumber.getSelectionStart();
int myend = destinationNumber.getSelectionEnd();
numberText.getText().replace(Math.min(mystart, myend), Math.max(mystart, myend),
"1", 0, 1);
its entering fine according to the cursor position.
i have a delete button in my acitivity which deletes single character according to cursor postion.
numberText.getText().delete(myend - 1, mystart);
But this logic is not working properly when i select whole text and call delete method it gives me IndexOutOfBoundsException OR i select 4-5 digits and call this delete.
I want the same functionality as android contact dialpad number enter field.Can someone help me figure out what is the correct logic to delete single digit from edittext and multiple selected digits as well.
Thanks
delete receives the start as first parameter and end as second, not the other way around.
Probably the error its taht mystart or myend(probably this) are bigger or smoller than numberText.lenght().
Try to put a Log.d("","" ) with the lenght of the text, mystart and myend and check if you need a myend -1 or something like that.
I have an editText that displays $0.00. When a user clicks on that, I want a numpad to come up. If they press 5, it should display $0.05, they press 3, it goes $0.53, they press 7 it goes $5.37, etc.
So far I have the editText displaying $0.00 and it brings up a numpad but you need to delete the numbers up to the $ sign and input the decimal yourself. I've had a few really complex ideas but I'm not sure I'm going about it the right way. Any suggestions?
You could use a variable protected int curValue = 0;
And set the editText each time a new number is pressed,
curValue *= 10; curValue += pressedNumber; editText.setText("$"+curValue/100.0f);
(as long as you don't need real big numbers)
Have you by chance taken a look at the android ref for currency?
http://developer.android.com/reference/java/util/Currency.html