义齿

- (UIImage *)_scaleToSize:(UIImage *)img size:(CGSize)size{
    
    //            context
    UIGraphicsBeginImageContext(size);
    //          
    [img drawInRect:CGRectMake(0, 0, size.width, size.height)];
    //    context             
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    //     context   
    UIGraphicsEndImageContext();
    //             
    return scaledImage;
}