iPhone SDK: How to trigger drawRect on UIView subclass after orientation change?

Question

I am subclassing a UIView and overwrite the drawRect method. I'm noticing that the view's drawrect is only being called when the view first loads. After that it is never called again. How to I make sure it gets called after an orientation change? I've tried calling setNeedsDisplay on the view before and after the rotation and that doesn't do it.

Cabinet

Answer 1

[myView setContentMode:UIViewContentModeRedraw];

You can set this in IB as well (i.e., set mode to "redraw")

Ashlieashlin

See the original author's response below. setNeedsDisplay is indeed the right method call. – Vigilance

setNeedsDisplay: is used when you want to programmatically trigger a redraw. When you want orientation changes to trigger a redraw then setContentMode: is the ticket. – Ashlieashlin

Answer 2

This was a bug related to something completely different. setNeedsDisplay does indeed cause drawRect to be called.

Cabinet

Yes setNeedsDisplay: will trigger a redraw, but requires the programmer to explicitly invoke it. 'setContentMode:` will automagically trigger a redraw on an orientation change. – Ashlieashlin

Answer 3

to answer this and the other 94,000 similiar questions about view rotation/drawrect funkiness,

-(id)initWithFrame:(CGRect)frame
{
    if(self=[super initWithFrame:frame]) {
        self.autoresizesSubviews=YES;
        self.autoresizingMask=UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
    }
    return self;
}

Quito