iPhone / Objective-C Code Examples (and .NET equivalents)

I have found myself reusing a lot of the same code throughout my apps. I thought I would publish some tips and code snippets to hopefully get you going on your next project. Here they are, in no particular order. I also tried to put a .NET equivalent for those of you who, like me, are coming from a long .NET background.

1) Use NSLog liberally to debug as you write your code. You can really do a lot with it. A few standard statements are for printing strings or numbers, and you can also print an Objective-C object. Here are the three I use most often:

NSLog(@"%@", aString); // prints any NSString, for example
NSLog(@"%d", anInt); // prints a signed int
NSLog(@"%f", aFloat); // prints a float

2) If you have a UITableView that you need to have updated, you can reload it with this command (assuming it is named "tableView"):

[self.tableView reloadData];

3) Need to iterate through a collection? Try this handy code snippet, which is similar to For Each in .NET languages:

for (id currentObject in allObjects) {
// do something here with currentObject

4) Here is how you can check to see if an object is certain type. This is a bit like using gettype or typeof in .NET to find a specific type:

if ([myObject isKindOfClass:[TheClassIAmLookingFor class]]) {

5) Here is how you cast an object in Objective-C, like using CType or DirectCast in .NET:

TypeToCastTo typeCastObject = (TypeToCastTo *)myObject;

6) I show alert pop-ups a lot in my apps. Here is a simple example for an alert launched when a button is clicked, and responded to to perform some action.

-(void)resetClicked:(id)sender withEvent: (UIEvent *) event {

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Reset" message:@"Are you sure you want to reset this puzzle?\nAll of your work will be lost!" delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"OK", nil];
[alert show];
[alert release];


- (void)alertView:(UIAlertView *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex {
// the user clicked the OK button
if (buttonIndex == 1)
// reset logic goes here



7) Split is a great function in .NET. Here is the Objective-C equivalent:

NSArray *arrayOfValues = [commaDelimitedListOfValues componentsSeparatedByString:@","];

More code snippets next time! Good luck!


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