func creatImageWithColor(color:UIColor)->UIImage{
        let rect = CGRect(x:0,y:0,width:1,height:1)
        UIGraphicsBeginImageContext(rect.size)
        let context = UIGraphicsGetCurrentContext()
        context?.setFillColor(color.cgColor)
        context!.fill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image!
    }