Question

Before/After call the block, the retaincount is always 1.
From apple block doc we know that the self should retain. Can anyone know why?

NSLog(@"Before block retain count: %d", [self retainCount]);    
void (^block)(void) = ^(void){
    UIImage* img = [UIImage imageNamed:@"hometown.png"];
    [self setImage:img];
    NSLog(@"After block retain count: %d", [self retainCount]);
};
block();

Answer 1

First, retainCount is useless. Don’t call it..

Blocks only retain captured objects when the block is copied. Thus, self won’t be retained by the block in that example.