Question

I am subclassing UIButton.
But I need to know the state that the button is in to draw the color of button for up or down:

- (void)drawRect:(CGRect)rect{
     if (state==UIControlStateNormal) {
         //draw rect RED
     }
     if (state==UIControlEventTouchDown) 
         //draw rect BLUE
     }
}

Answer 1

Did you even try looking at the docs?

1. Goto UIButton Reference
2. Check the properties
3. Nothing obvious
4. See if UIButton has a superclass
5. Goto UIControl Reference – UIButton‘s superclass
6. Check the properties
7. Oh look there is a state property

---

Update

The accepted answer is slightly incorrect and could lead to some annoyingly difficult bug to track down.

The header for UIControl declares state as

@property(nonatomic,readonly) UIControlState state;                  // could be more than one state (e.g. disabled|selected). synthesized from other flags.

Now looking up to see how UIControlState is defined we see

enum {
    UIControlStateNormal       = 0,                       
    UIControlStateHighlighted  = 1 << 0,                  // used when UIControl isHighlighted is set
    UIControlStateDisabled     = 1 << 1,
    UIControlStateSelected     = 1 << 2,                  // flag usable by app (see below)
    UIControlStateApplication  = 0x00FF0000,              // additional flags available for application use
    UIControlStateReserved     = 0xFF000000               // flags reserved for internal framework use
};
typedef NSUInteger UIControlState;

Therefore as you are dealing with a bit mask you should check for the state appropriately e.g.

if (self.state & UIControlStateNormal) { ... } 

---

Update 2

You could do this by drawing into an image and then setting the image as the background e.g.

- (void)clicked:(UIButton *)button;
{
    UIGraphicsBeginImageContext(button.frame.size);

    // Draw gradient

    UIImage *gradient = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    [button setBackgroundImage:image forState:UIControlStateNormal];
}