Convert string to Dapper's DbString with StringLengthAttribute and UnicodeAttribute.

ToDbString.cs

public static DbString ToDbString<T>(this string value, string key, bool? IsFixedLength, int? MaxLength, bool? IsAnsi)
{
    var property = typeof(T).GetProperty(key);

    var attrLength = property?.GetCustomAttributes<StringLengthAttribute>().SingleOrDefault();
    var maxLength = MaxLength ?? attrLength?.MaximumLength ?? DbString.DefaultLength;

    var attrAnsi = property?.GetCustomAttributes<UnicodeAttribute>().SingleOrDefault();
    var isAnsi = IsAnsi ?? attrAnsi?.IsUnicode switch
    {
        null => DbString.IsAnsiDefault,
        true => false,
        false => true,
    };

    return new DbString
    {
        Value = value,
        Length = maxLength ,
        IsFixedLength = IsFixedLength ?? false,
        IsAnsi = isAnsi
    };
}