Warning: 'UIDevice' may not respond to '-isMultitaskingSupported'

I am working with n开发者_如何学Cew FBConnect for iPhone. But I have followed the steps given.. but when i build it shows me this warning "Warning: 'UIDevice' may not respond to '-isMultitaskingSupported'" and the app crashes. I am using iphone simulator 4.1 and still it is showing me this warning. If anyone can help me out with this it will be great.

Thanks in advance.

---

Versions of iOS prior to 4.0 don't have this method, so you have to use respondsToSelector to first check that the method is present prior to calling it.

if ([[UIDevice currentDevice] respondsToSelector:@selector(isMultitaskingSupported)] && [[UIDevice currentDevice] isMultitaskingSupported]) {
    // Device supports multi-tasking...

}
else {
    // No such luck.
}

As such, whilst you're using the iPhone simulator 4.1, I'm guessing that you've set the iOS version to 3.2 (use the Version option on the Hardware menu to change this).

---

You can Add below mention methode yo your Project to check If device support multi threading before any action

- (BOOL) isMultitaskingSupported
{
    BOOL result = NO;
    UIDevice *device = [UIDevice currentDevice];

    if (device != nil)
    { 
        if ([device respondsToSelector:@selector(isMultitaskingSupported)] == YES)
        { 
            #ifdef __IPHONE_4_0 
                #if (__IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_4_0)
                    result = [device isMultitaskingSupported]; 
                #endif
            #endif
        } 
        return(result);
    }
}

This will return Bool i.e True in case device supports Multitasking