Manipulating textfield values in an iPhone app - cocoa-touch

How do I manipulate textfield variables within an iPhone app? I want to have three text fields, formatted to numbers only, and be able to manipulate the data when I press different buttons.
Any help would be appreciated!

UITextField objects have a "text" property of type NSString that can be read and written. Keep a reference to the text fields, and when a button is pressed, update the field's text property with a new NSString to change its contents. If the text fields are not directly editable by the user, you may want to use UILabel instead, which is basically just a non-editable text field (and which also has a read/write "text" property).

You may also want to read about the NSNumberFormatter class that allows you to format the input into whatever way is relevant to your application (currency values, floats, etc).

To solve the problem of editing certain text fields, you could disable the user interaction until a button is pressed.

Related

automatically updating a label objective-c without clicking a button

I have 4 labels, 3 are editable with one label that cant be edited and one float which is the sum of the 3 editable labels. Whats the easiest way to get the uneditable label to update automatically with the summed value of the other labels as the user edits them? (i dont want the user to have to click a button after the user has edited the labels) I know i'll probably be using bindings but your help is very appreciated.
Assuming your three editable labels are actually "text fields", designate some object (probably your view controller) as a delegate and then respond to this NSControlTextEditingDelegate protocol method:
- control:shouldEndTextEditing:
When the user tabs or exits the editable text field, you'll catch that event via the protocol method and then you can update that non-editable text field (which you've set to an outlet in your view controller, right?).
Or, you can use bindings, yes. :-)

UITextField - Action on resignFirstResponder -- possible?

I have created a form that has a number of text fields that save to NSStrings that are then used deeper in the app.
Currently, if you hit the return key (done) on the GUI keyboard, the keyboard is dismissed, and the data in the text field is saved to its NSString. Likewise, if the background is touched the same occurs.
However, if I touch another text field, without doing one of the above first, the variable is not saved. Is there a way to do this? Perhaps a way to perform an action when a specific text field release firstresponder?
The best solution for your issue is just to use the
-(void)textFieldDidEndEditing:(UITextField *)textField
And then you can just access the textField and store the textFields text in the appropriate string every time focus is lost.

Matching text in UITextField to a list in UITableView

In my app I have a text box, a table view, and a database. I want to make it so that when I click on the text box and write something in it, my table view will display the list of words similar or identical to the word or words I have entered into the text field. Please, can anyone provide me a suitable idea for implementing this? Thanks.
Whenever you edit text field, the delegate method textField:shouldChangeCharactersInRange:replacementString: gets called. Use this to fetch records from database and reload the tableview.
See similar post here and apple's sample code here

How can I programmatically add a text field with a decimal pad keyboard in Xcode 4?

I needed to add a UIKeyboardTypeDecimalPad keyboard to a decimal field, which can only be done programatically. I need the full code (I'm pretty new to Objective-C) to make a UIKeyboardTypeDecimalPad pop up when someone touches inside the text box. I'd also like to add the text field programmatically.
Basically, I need to add a text field with a UIKeyboardTypeDecimalPad keypad. Or, if possible, just the keypad to a text field made in Interface Builder.
Does anyone know a good tutorial for this or can anyone give me the full code themselves, and tell me where I need to put it (the .m or .h or what?)?
Thanks!
Update: As mentioned in the comment below, could I see example code for an app that does this?
To set the keyboard type to UIKeyboardTypeDecimalPad, just assign that value to the text field's keyboardType property.
textField.keyboardType = UIKeyboardTypeDecimalPad;
Adding a text field programmatically is only slightly more work: UITextField *textField = [[[UITextField alloc] initWithFrame:frame] autorelease]; to create it, then set any properties you need to set, and add it to the appropriate view with addSubview:.
In your view controller's viewDidLoad method is a good place for this sort of thing. Or if you're loading a view without a controller from the nib, use the view's awakeFromNib method.

How to intercept text from the keyboard and format it before it show in the cell?

Part of the program I'm developing stores user-entered phone numbers, so I'd like to format them as they are entered. I've got the NSFormatter working when text is displayed in the cell from stored data, but I don't know how to format a phone number as it's being entered on the keyboard, as in Apple's contacts app.
How can I accomplish this?
Set the delegate of the text field to you controller class, implement the UITextFieldDelegate protocol and put your formatting code in the textField:shouldChangeCharactersInRange:replacementString: method.