// Create the path data

CGMutablePathRef cgPath = CGPathCreateMutable();

CGPathAddEllipseInRect(cgPath, NULL, CGRectMake(0, 0, 300, 300));

CGPathAddEllipseInRect(cgPath, NULL, CGRectMake(50, 50, 200, 200));

// Now create the UIBezierPath object

UIBezierPath* aPath = [UIBezierPath bezierPath];

aPath.CGPath = cgPath;

aPath.usesEvenOddFillRule = YES;

// After assigning it to the UIBezierPath object, you can release

// your CGPathRef data type safely.

CGPathRelease(cgPath);

UIBezierPath*    aPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(0, 0, 300, 300)];

// Get the CGPathRef and create a mutable version.

CGPathRef cgPath = aPath.CGPath;

CGMutablePathRef  mutablePath = CGPathCreateMutableCopy(cgPath);

// Modify the path and assign it back to the UIBezierPath object

CGPathAddEllipseInRect(mutablePath, NULL, CGRectMake(50, 50, 200, 200));

aPath.CGPath = mutablePath;

// Release both the mutable copy of the path.

CGPathRelease(mutablePath);

- (void)drawRect:(CGRect)rect

{

    // Create an oval shape to draw.

    UIBezierPath* aPath = [UIBezierPath bezierPathWithOvalInRect:

                                CGRectMake(0, 0, 200, 100)];

    // Set the render colors

    [[UIColor blackColor] setStroke];

    [[UIColor redColor] setFill];

    CGContextRef aRef = UIGraphicsGetCurrentContext();

    // If you have content to draw after the shape,

    // save the current state before changing the transform

    //CGContextSaveGState(aRef);

    // Adjust the view's origin temporarily. The oval is

    // now drawn relative to the new origin point.

    CGContextTranslateCTM(aRef, 50, 50);

    // Adjust the drawing options as needed.

    aPath.lineWidth = 5;

    // Fill the path before stroking it so that the fill

    // color does not obscure the stroked line.

    [aPath fill];

    [aPath stroke];

    // Restore the graphics state before drawing any other content.

    //CGContextRestoreGState(aRef);

}