How do i set custom font

Hi,

I am newbie to this,

May i know How do i use custom font in xamarin forms,

Following example doesn't work for me,

m_lblText = new Label
{
            Text = _lblText,
            FontFamily = Device.OnPlatform(
                "SF Hollywood Hills",
                "SF Hollywood Hills",
                "SF Hollywood Hills"
            ),               
};

And i Store "SF Hollywood Hills.ttf" font file in ios projects Resource folder.

I am not able to set the custom font.

Thanks,