问对于年份选择是可选的iOS，是否有自定义的日期选择器？

EN

public override void Draw (CGRect rect)
{
    base.Draw (rect);
    DatePicker elem = (DatePicker)Element;
    UITextField textField = (UITextField)Control;

    var toolbar = new UIToolbar(new CGRect(0.0f, 0.0f, Control.Frame.Size.Width, 44.0f));

    toolbar.Items = new[]
    {
        new UIBarButtonItem(UIBarButtonSystemItem.Cancel,(object sender, EventArgs e) => {
            if (elem.SetValueNullAction!=null){
                elem.SetValueNullAction();
                textField.Text = DefaultNotSetText;
            }
        }),
        new UIBarButtonItem(UIBarButtonSystemItem.FlexibleSpace),
        new UIBarButtonItem(UIBarButtonSystemItem.Done,(object sender, EventArgs e) => {
            elem.Unfocus();
        })
    };

    textField.InputAccessoryView = toolbar;
    textField.BorderStyle = UITextBorderStyle.None;
    textField.TextColor = Color.FromHex ("999999").ToUIColor ();
    CGRect frame = textField.Frame;
    frame.Width = 100;
    textField.Frame = frame;
    if (elem.Date == elem.MinimumDate) {
        textField.Text = ((DatePicker)this.Element).Label;
    }

}