Swift sets the navigation bar transparent

Swift sets the navigation bar to be transparent, that is, to set an empty picture, but if you only set this code, does not work, but also need other settings, directly on the code

        1. Set navigation bar Title properties: Set title Color        Self.navigationcontroller?. Navigationbar.titletextattributes = [NSForegroundColorAttributeName:UIColor.white]        //2. Set navigation bar foreground color: Set Item indicator        Self.navigationcontroller?. Navigationbar.tintcolor = Uicolor.purple                //3. Set the navigation bar translucent        Self.navigationcontroller?. Navigationbar.istranslucent = True                //4. Set the navigation bar background picture        Self.navigationcontroller? Navigationbar.setbackgroundimage (UIImage (), For:UIBarMetrics.default)                //5. Set the navigation bar shadow picture        Self.navigationcontroller?. Navigationbar.shadowimage = UIImage ()

Swift sets the navigation bar transparent