C#

10.9.3 Conversion operators (C#)[^]

A class or struct is permitted to declare a conversion from a source type S to a target type T provided all of the following are true:

• S and T are different types.
• Either S or T is the class or struct type in which the operator declaration takes place.
• Neither S nor T is object or an interface-type.
• T is not a base class of S, and S is not a base class of T.

...
User-defined conversions are not allowed to convert from or to interface-types. In particular, this restriction ensures that no user-defined transformations occur when converting to an interface-type, and that a conversion to an interface-type succeeds only if the object being converted actually implements the specified interface-type.

SqlDataAdapter sda = new SqlDataAdapter("select count(*) from Login Whare Username = textUsername.Text ; Password = textPassword.Text; +", conn);
DataTable dt = new System.Data.DataTable();

string s = "select count(*) from Login Whare Username = textUsername.Text ; Password = textPassword.Text; +";

from Login Whare Username

Whare Username = textUsername.Text ; Password = textPassword.Text

public enum GenderType  // this is Thailand ...
     Indeterminate,
     Ambivalent,
     RefuseToState,
     Male,
     Female,
     Hermaphrodite,
     TransPreOpMToF,
     TransPreOpFToM,
     TransPostOpMToF,
     TransPostOpFToM,
     Eunuch,
     Alien
}

private Array EnumTypeValues { set; get; }
private BindingSource EnumBindingSource { set; get; }

public void SomeMethod(Type enumtype, ComboBox combo)
{
    EnumTypeValues = Enum.GetValues(enumtype);

    EnumBindingSource = new BindingSource();
    EnumBindingSource.DataSource = EnumTypeValues;
    combo.DataSource = EnumBindingSource;
    combo.DisplayMember = "Name";

    combo.SelectedValueChanged += ComboOnSelectedValueChanged;
}

// assuming you've called 'SomeMethod passing the Enum, and a reference to a ComboBox:
// SomeMethod(typeof(GenderType), comboBox1);


private void ComboOnSelectedValueChanged(object sender, EventArgs eventArgs)
{
    GenderType gType = (GenderType) comboBox1.SelectedValue;

    switch (gType)
    {
        case GenderType.Indeterminate: 
            // do something
            break;
        case GenderType.Male:
            // do something else
            break;
        case GenderType.Female:
            // do something else
            break;
        case GenderType.Ambivalent:
            // get Eddie Izzard out of here
            break;
        case GenderType.Alien:
            // call Area 51
            break;
        default:
            break;
    }
   // update other data-structures, or Controls ?
}

BillWoodruff wrote:

public enum GenderType // this is Thailand ...

Member 12482866 wrote:

What is the best practice to get me going?

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]