Rotate CGPDFDocument/Page

I'm loading a CGPDFDocument, adding that as a sublayer to a UIView (myContentView), and then adding myContentView to a UIScrollView. That works fine. Now I want to allow the user to rotate the PDF if they choose to. It's easy to get the PDF to initially display with some rotation- I just do it here:

- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx {
    CGContextSaveGState (ctx);
    CGContextSetRGBFillColor(ctx, 1.0, 1.0, 1.0, 1.0);
    CGContextFillRect(ctx, CGContextGetClipBoundingBox(ctx));
    CGContextTranslateCTM(ctx, 0.0, layer.bounds.size.height);
    CGContextScaleCTM(ctx, 1.0, -1.0);
    CGContextConcatCTM(ctx, CGPDFPageGetDrawingTransform(myPageRef, kCGPDFCropBox, layer.bounds, rotation, true));
    CGContextDrawPDFPage(ctx, myPageRef);
    CGContextRestoreGState (ctx);
}

But, how can I do it after the initial load?

Note: I've tried just rotating myContentView, which seems like it works, but after doing it, I can no longer zoom/unzoom the PDF... I think what I need is to force drawLayer to be calle开发者_开发知识库d again with a new value in "rotation"... how do I do that?

Thanks, Steve

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To signal that the layer needs to be redrawn, send it a setNeedsDisplay or setNeedsDisplayInRect: message. You have to store the desired rotation angle in an ivar/property and access that value from drawLayer:inContext:.

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try calling setNeedsDisplay on your layer