PDF Rendering white background

pdfmultipage.m

- (NSData *)PDFDataForMultiPageDocument {
    NSMutableData *data = [NSMutableData data];
    CGDataConsumerRef consumer = CGDataConsumerCreateWithCFData((CFMutableDataRef)data);
    if (NULL == consumer) {
        NSLog(@"could not create consumer");
        return nil;
    }
    
    CGRect r = CGRectMake(0.0, 0.0, 800.0, 600.0);;
    
    CGContextRef ctx = CGPDFContextCreate(consumer, &r, NULL);
    CFRelease(consumer);
    
    NSGraphicsContext *gc = [NSGraphicsContext graphicsContextWithGraphicsPort:ctx flipped:NO];
    
    
    CGContextBeginPage(ctx, &r);
    CGContextSaveGState(ctx);
    
    //    CGContextClearRect(ctx, r);
    const CGFloat clearColor[] = {1.0, 1.0, 0.0, 1.0};
    CGContextSetFillColor(ctx, clearColor);
    CGContextFillRect(ctx, CGRectMake(10.0, 10.0, 50.0, 50.0));
    
    CGContextSetStrokeColor(ctx, clearColor);
    CGContextStrokeEllipseInRect(ctx, r);
    
    CGContextRestoreGState(ctx);
    CGContextEndPage(ctx);
    
    
    CGPDFContextClose(ctx);
    CGContextRelease(ctx);
    
    return data;
}