Change UIImageViews image from UIButton

[learningtocode]

I have been unsuccessful in the finding this answers. What is the best way to change a UIImageView's image that is on ViewController 1, from UIButtons from ViewController2?

[JamesCahall]

Originally Posted by learningtocode

I have been unsuccessful in the finding this answers. What is the best way to change a UIImageView's image that is on ViewController 1, from UIButtons from ViewController2?

There are several ways to do this. Here is one.

On viewcontroller 1, create an observer in viewDidLoad

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(methodToRun) name:@"RunThisMethod" object:nil];

Note: Be sure to add this to dealloc:
[[NSNotificationCenter defaultCenter] removeObserver:self name:@"RunThisMethod" object:nil];

Add the method to change the image:

- (void)methodToRun {
self.someImageView.image = [UIImage imageNamed:@"New_Image.jpg"];
}

On view controller 2, add the postNotification call to the button action:

[button addTarget:self action:@selector(sendPost) forControlEvents:UIControlEventTouchUpInside];

Add the method sendPost:

- (void)sendPost {
[[NSNotificationCenter defaultCenter] postNotificationName:@"RunThisMethod" object:nil];
}

That's it. If you need the new image to be variable, change methodToRun to methodToRunNSNotification *)notification and send a userInfo dictionary with the postNotification that has the image string.

Alternatively, you could store the image string in a singleton that is written by one, and read by the other. A notification would not be necessary if you changed the image in viewWillAppear of view controller 1 based upon the image string stored in the singleton.

Hope that helps.

[Domele]

Unless lots of objects need to know about the changed image, notifications are not the way to go. You should create a property on view controller 1 that you set from view controller 2.

[learningtocode]

Originally Posted by Domele

Unless lots of objects need to know about the changed image, notifications are not the way to go. You should create a property on view controller 1 that you set from view controller 2.

That sounds like the direction I need to go. Do you know a good resource to learn how to do this? Thank you guys for your quick responses!!

[Domele]

http://www.iphonedevsdk.com/forum/ip...roperties.html