Objective c loop with time delay - objective-c

Question

I want that every object from the NSMuttableArray to appear for 4 sec. and than disappear.And on this way to iterate all items from the array.Instead the result i got is that all items appears and after the period disappear together.
-(void)showTreasures{
for (int i = 0; i < _treasures.count; i++)
{
SKSpriteNode *obj = [_treasures objectAtIndex:i];
SKAction *show = [SKAction runBlock:^{
obj.hidden = NO;
}];
SKAction *wait = [SKAction waitForDuration:4];
SKAction *hide = [SKAction runBlock:^{
obj.hidden = YES;
}];
SKAction *sequence = [SKAction sequence:#[show, wait, hide]];
[obj runAction:sequence completion:^{
NSLog(#"Item %d", i);
}];
}
}

Answer 1

I think it's good job for recursive method, method which call itself.
You can created array of all of your objects (SKSpriteNode) and pass it to the method which takes first (or last) object and run appropriate action, remove the object and call the method again:
NSMutableArray *arrOfObject = //arrat with all of the sprites you want to show
[self runShowAction:arrOfObject];
-(void)runShowAction:(NSMutableArray*)array {
//if no object in the array return
if(array.count <= 0) return;
SKSpriteNode *obj = [array firstObject];
//Run your code here
//...
//On completion remove object from array and run this method again
[obj runAction:sequence completion:^{
NSLog(#"Item %d", i);
[array removeObject:obj];
[self runShowAction:array];
}];
}

Answer 2

Why don't you use an array to build up a list of all the actions, then run a sequence of all of those actions?
-(void)showTreasures
{
NSMutableArray *actions = [NSMutableArray array];
for (int i = 0; i < _treasures.count; i++)
{
SKSpriteNode *obj = [_treasures objectAtIndex:i];
SKAction *show = [SKAction runBlock:^{
obj.hidden = NO;
}];
SKAction *wait = [SKAction waitForDuration:4];
SKAction *hide = [SKAction runBlock:^{
obj.hidden = YES;
}];
SKAction *finish = [SKAction runBlock:^{
NSLog(#"Item %d", i);
}];
[actions addObjectsFromArray:#[show, wait, hide, finish]];
}
SKAction *sequence = [SKAction sequence:actions];
[obj runAction:sequence completion:^{
NSLog(#"Finished all items");
}];
}