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Category Archive for ‘Q&A’ rss

Should I Release Outlets?

bqbqhaha asks:

Let me ask you something as below.

  1. A variable declared as IBOutlet could be released?
  2. A variable declared as IBOutlet should be released?

I search for this issue many times, but still the answer is not found.
plz help me , plz

He is asking a question that most of us have when beginning with Interface Builder and Outlets. In plain English his question is “Should I release instance variables declared as IBOutlet?”

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Date Closest to 'NOW'

Nagarajan asks:

I have needed a SQLite query that returns exactly a time which is very closest to the current time.

From 7:00pm,8:00pm, 9:00am and 10:00pm if the current time is 8:30pm, I will require 10:00pm.

This is more of a SQLite question than related to Cocoa Touch. But since SQLite is the mobile database engine of choice for Cocoa Touch, I’ll entertain this question as well. And follow it up with some Cocoa Code.

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Adding Numbers to an Array

reembertoparada asks:

I have a loop from 1 to 30 and I want to create an NSArray with those values inside. Can you give me an idea on how to do this.

That’s an easy after-dinner exercise. First you need to take an NSMutableArray instead of an NSArray because regular objects without “mutable” in their class name cannot be changed. This is especially vital to know for arrays and dictionaries.

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Adding Days to an NSDate

Nagarajan asks:

I just want to get a date which is some 50 or 60 days away from current date.

How do i get??

There are two methods to achieving this. One that is quick and (potentially) dirty. And one that is always safe.

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How to Fix Code Signing Errors

Andreas asks:

With Device | Debug and Code Sign “iPhone Developer” I have no problems getting my app onto the device, but with all other configurations I get this strange error message in XCode Organizer.
Unexpected Error

That’s a weird error that most of us have encountered one time or the other. Here are my hints how to get it fixed.

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Shorter Back Buttons

Today, on the train to the big city, I watched the seventh Standford iPhone Programming lecture and got an answer to a question I’ve been having for a long time.

Can I make the back button shorter in a UINavigationView? I like long titles, but it looks ugly on the back button!

The back button of a view that you pushed on the the navigation stack defaults to the previous view controller’s title. You want to make the title explanatory so a long one is good. But if you push another view controller onto the navigation stack you want the space to have an explanatory title on this one, or you need the space for something else.

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Contacting the App Delegate

Remover asks:

How to send a message from a view controller to app delegate?

That’s a question that everybody asks who is trying to follow the model-view-controller paradigm. There is an easy way to access your app delegate from anywhere in your app.

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Learn to Say No

This request of MKureth is so totally crazy that I just had to share it with you:

Hi, I am currently working 60+ hours a week on highly advanced interactive development which mainly consists of Flash (AS3), XML, JavaScript, PHP, and MySQL. I was asked to learn and develop a working iPhone application using the frameworks of Cocoa, Objective-C, and OpenGL within two weeks. Given my current work schedule and skill sets, how should I proceed with this request and deadline (of two weeks) keeping in mind that I have no prior experience with Mac development?

As impressive as your resumé sounds you lack a couple of essential skills.

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The Best Way to Save Data

BebopSong asks:

Can anyone tell me the best way to create and store data on the iPhone so that the app can read the data but also write to it?

Having tried out all the possibilities that the iPhone platform holds in stock, here’s my opinion.

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NSString Category for Compressing Whitespace

Anonymous users keep asking:

How do I remove whitespace characters from a string?

A quick way to do that is to first split the words in the string by whitespace characters and then join them back together without seperator. But there is a more elegant way to achieve this, that’s reusable at the same time: extend NSString by adding a category to compress whitespace to an arbitrary seperator.

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