Creating Visual Web Part Properties

[ToolboxItemAttribute(false)]
public class Sample_Web_Part : WebPart
{
 
    protected override void CreateChildControls()
    {
     
    }

    public static Boolean SampleBoolean;
    [Category("Extended Settings"),
    Personalizable(PersonalizationScope.Shared),
    WebBrowsable(true),
    WebDisplayName("Sample Boolean"),
    WebDescription("Please Choose a Sample Boolean")]
    public Boolean _SampleBoolean
    {
        get { return SampleBoolean; }
        set { SampleBoolean = value; }
    }

    public static string SampleText;
    [Category("Extended Settings"),
    Personalizable(PersonalizationScope.Shared),
    WebBrowsable(true),
    WebDisplayName("Sample Text"),
    WebDescription("Please Enter a Sample Text")]
    public string _SampleText
    {
        get { return SampleText; }
        set
        {
            // Sample Validation
            Regex oRegEx = new Regex("[a-zA-Z]+");
            if (!oRegEx.IsMatch(value))
                throw new Microsoft.SharePoint.WebPartPages.
                    WebPartPageUserException(
                    "Please enter alphabeth characters only");
            SampleText = value;
        }
    }

    public static int SampleNumber;
    [Category("Extended Settings"),
    Personalizable(PersonalizationScope.Shared),
    WebBrowsable(true),
    WebDisplayName("Sample Number"),
    WebDescription("Please Enter a Sample Number")]
    public int _SampleNumber
    {
        get { return SampleNumber; }
        set { SampleNumber = value; }
    }

    public static DateTime SampleDate;
    [Category("Extended Settings"),
    Personalizable(PersonalizationScope.Shared),
    WebBrowsable(true),
    WebDisplayName("Sample Date"),
    WebDescription("Please Enter a Sample Date")]
    public DateTime _SampleDate
    {
        get { return SampleDate; }
        set { SampleDate = value; }
    }

    public enum CityEnum { Mumbai,Aukland, Londan,Sydney };
    public static CityEnum SampleDropDown;
    [Category("Extended Settings"),
    Personalizable(PersonalizationScope.Shared),
    WebBrowsable(true),
    WebDisplayName("Sample Drop Down"),
    WebDescription("Please Choose a Sample DropDown")]
    public CityEnum _SampleDropDown
    {
        get { return SampleDropDown; }
        set { SampleDropDown = value; }
    }
}