changing uiimageview position through selector

[heavenking]

i'm trying to change the position of my image view after time delay like in the following code

 CGPoint pointOne=CGPointMake(150, 200);
	UIImageView *sampleImage=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"hello.png"]];
	[sampleImage performSelector:@selector(setCenter:) withObject:[NSValue valueWithCGPoint:pointOne] afterDelay:0.5];

it does not works properly because image view does not accept the nsvalue plz say any other solution to pass the cgpoint as the object. Thanks in advance.

[JDave]

A CGPoint is 'two' numbers, made up of two CGFloats (floats). It is an 'x' and a 'y'. You will need to wrap your selector with a larger statement like:

... withObject:CGPointMake([NSValue valueWithCGPoint:pointXOne] ,[NSValue valueWithCGPoint:pointYOne]) ...

[Duncan C]

Originally Posted by heavenking

i'm trying to change the position of my image view after time delay like in the following code

 CGPoint pointOne=CGPointMake(150, 200);
	UIImageView *sampleImage=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"hello.png"]];
	[sampleImage performSelector:@selector(setCenter:) withObject:[NSValue valueWithCGPoint:pointOne] afterDelay:0.5];

it does not works properly because image view does not accept the nsvalue plz say any other solution to pass the cgpoint as the object. Thanks in advance.

You can't pass non-object parameters using performSelector:withObject:afterDelay:

In order to do that, you'll need to create an additional method. Say you call it moveImage:

-(void) moveImage
{
  [sampleImage setCenter: CGPointMake(150, 200)];
}

...
  UIImageView *sampleImage=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"hello.png"]];
  [self performSelector: @selector(moveImage) withObject: nil afterDelay: 0.5];

There is another Cocoa feature called NSInvocation that lets you invoke an arbitrary method with any types of parameters much like the "performSelector" methods, but I haven't used it.

[heavenking]

Originally Posted by Duncan C

You can't pass non-object parameters using performSelector:withObject:afterDelay:

In order to do that, you'll need to create an additional method. Say you call it moveImage:

-(void) moveImage
{
  [sampleImage setCenter: CGPointMake(150, 200)];
}

...
  UIImageView *sampleImage=[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"hello.png"]];
  [self performSelector: @selector(moveImage) withObject: nil afterDelay: 0.5];

There is another Cocoa feature called NSInvocation that lets you invoke an arbitrary method with any types of parameters much like the "performSelector" methods, but I haven't used it.

thanks duncan i agree your first way mostly i use this way only. but actually i want to avoid making additional methods for this thinks thats why i use the selector method. can you give a sample code for NSInvocation to pass non object arguments. Thanks in advance

[rickrets]

NSInvocation Class Reference

Have a blast