View source for MoPhO/iPhoneDevelopment

= Code snippets =

'''Pleas add any snippet of code that you think might be helpful to others.'''


=== Update view from a different thread (not the main thread) ===

If you have a function that runs on a different thread and you want to update something in a View, you will need to add a <code>NSAutoreleasePool</code> to that thread (or at least the function) and then you need to call the <code>performSelectorOnMainThread</code> method on the view or object you are updating.

For example, assuming that <code>data</code> is a pointer to a <code>UILabel</code> in the view that we want to update in the callback:

<pre>
// Function not running in the Main Thread 
void callback( void * data )
{
    NSAutoreleasePool *autoreleasepool = [[NSAutoreleasePool alloc] init];
    UILabel * me = (UILabel *)data;
    [me performSelectorOnMainThread:@selector(setText:) withObject:@"New text" waitUntilDone:YES];
    [autoreleasepool release];
}
</pre>

Instead of a <code>UILabel</code> you can pass any other widget.