public static ProfitFormulaDBHelper GetInstance()
 {
     if (_Instance == null)
     {
         lock (typeof(ProfitFormulaDBHelper))
         {
             if (_Instance == null)
             {
                 _Instance = new ProfitFormulaDBHelper();
             }
         }
     }
     return(_Instance);
 }
 public static ProfitFormulaDBHelper GetInstance()
 {
     if (_Instance == null)
     {
         lock (typeof(ProfitFormulaDBHelper))
         {
             if (_Instance == null)
             {
                 _Instance = new ProfitFormulaDBHelper();
             }
         }
     }
     return _Instance;
 }