Tag Archives: iOS

UIAlertView – creating and detecting button tap

Declare the UIAlertView delegate in the yourViewController.h:

<UIAlertViewDelegate>

1	<UIAlertViewDelegate>

Create the alertView:

 UIAlertView *alert =
    [[UIAlertView alloc] initWithTitle: @"Here is my alert title."
                               message: @"Here is my alert message."
                              delegate: self
                     cancelButtonTitle: @"Cancel"
                     otherButtonTitles: @"OK", nil];
    [alert show];

UIAlertView *alert =

[[UIAlertView alloc] initWithTitle: @"Here is my alert title."

message: @"Here is my alert message."

delegate: self

cancelButtonTitle: @"Cancel"

otherButtonTitles: @"OK", nil];

[alert show];

Detect which alertView button was tapped:

 if (buttonIndex==0) {
        // button 0 tapped
        NSLog(@"Cancel %d", buttonIndex);

    }else if (buttonIndex==1){
        // button 1 tapped
        NSLog(@"OK %d", buttonIndex);
 }

if (buttonIndex==0) {

// button 0 tapped

NSLog(@"Cancel %d", buttonIndex);

}else if (buttonIndex==1){

// button 1 tapped

NSLog(@"OK %d", buttonIndex);

}

UIBarButtonItem – setting retina display and non-retina display toolBar icons

I can never remember how to handle retina display images versus non-retina display images in the toolbar so here’s a reminder:

Add the 2 files to your project:

image.png
image@2x.png

1 2	image.png image@2x.png

Then call it the same way on all screen densities:

[UIImage imageNamed:@"image.png"];

1	[UIImage imageNamed:@"image.png"];

UIImage will determine the right one to use. If using Interface Builder, point to the image.png and not the @2x image.

UIActivityIndicatorView – add activity indicator to navigation bar

Add an activity indicator as shown here:

UIActivityIndicatorView *activityIndicator = 
    [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];
UIBarButtonItem * barButton = 
    [[UIBarButtonItem alloc] initWithCustomView:activityIndicator];

// Set to Left or Right
[[self navigationItem] setRightBarButtonItem:barButton];

[barButton release];
[activityIndicator startAnimating];

UIActivityIndicatorView *activityIndicator =

[[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];

UIBarButtonItem * barButton =

[[UIBarButtonItem alloc] initWithCustomView:activityIndicator];

// Set to Left or Right

[[self navigationItem] setRightBarButtonItem:barButton];

[barButton release];

[activityIndicator startAnimating];

Remove the spinner and stop animating:

[[self navigationItem] setLRightBarButtonItem:nil];
[activityIndicator stopAnimating];

1 2	[[self navigationItem] setLRightBarButtonItem:nil]; [activityIndicator stopAnimating];

iOS Code Snippets

A collection of useful resources for iOS developers

Tag Archives: iOS

UIAlertView – creating and detecting button tap

UIBarButtonItem – setting retina display and non-retina display toolBar icons

UIActivityIndicatorView – add activity indicator to navigation bar