ขอโค๊ดเพิ่มไอดีออโต้ C# หน่อยคับ อยากได้โค๊ดเพิ่มไอดีของ C# อ่าครับ อย่างเช่นว่าเมื่อเรากดปุ่ม

Private Sub autoEmployee_ID()
        Dim sqlcmd As SqlCommand = New SqlCommand
        Dim dr As SqlDataReader
        Dim tempSql As String = "select Max(Employee_id) as Employee_id from Employee"

        Dim tempId As String
        open_conn()
        Try
            sqlcmd.CommandType = CommandType.Text
            sqlcmd.CommandText = tempSql
            sqlcmd.Connection = Mainmenuform.SqlConnection1
            dr = sqlcmd.ExecuteReader
        Catch ex As Exception
            MessageBox.Show(ex.Message)
            Exit Sub
        End Try
        dr.Read()
        If IsDBNull(dr.Item("Employee_id")) = True Then
            txtempid.Text = "EMP" & "0001"
        Else
            tempId = dr.Item("Employee_id")
            txtempid.Text = "EMP" & (tempId.Substring(3) + 1).ToString("0000")
        End If
        closeConn()
End Sub

Function GetNewEmployee_ID(ByVal varConnectionString As String) As String

        Dim iStr As String = String.Empty
        Dim cmdBuilder As System.Text.StringBuilder = New System.Text.StringBuilder()

        cmdBuilder.AppendLine("DECLARE @Counter          AS BIGINT ;")
        cmdBuilder.AppendLine("DECLARE @MaxCounter       AS BIGINT ;")
        cmdBuilder.AppendLine("DECLARE @Temp             AS INT ;")
        cmdBuilder.AppendLine("DECLARE @IDPrefix         AS Varchar(10);")
        cmdBuilder.AppendLine("DECLARE @TempStr          AS Varchar(MAX);")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("SET @IDPrefix = 'EMP-' ;")
        cmdBuilder.AppendLine("SET @Counter = 0 ;")
        cmdBuilder.AppendLine("SET @MaxCounter = 999999999999 ;")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("SELECT @TempStr = MAX([Employee_id]) FROM [Employee] ;")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("IF (LEN(@TempStr)>0) ")
        cmdBuilder.AppendLine("BEGIN")
        cmdBuilder.AppendLine("   SET @TempStr = SUBSTRING(LEN(@IDPrefix) +1,LEN(@TempStr));")
        cmdBuilder.AppendLine("   SET @Counter = CONVERT(BIGINT ,@TempStr) ;")
        cmdBuilder.AppendLine("END ")
        cmdBuilder.AppendLine("ELSE")
        cmdBuilder.AppendLine("   SET @Counter = 0 ;")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("SET @Counter = @Counter +1 ;")
        cmdBuilder.AppendLine("IF (@Counter > @MaxCounter)")
        cmdBuilder.AppendLine("   SET @Counter = 1 ;")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("-- FORMAT DATA FOR OUTPUT")
        cmdBuilder.AppendLine("SET @Temp = LEN(@MaxCounter) ;")
        cmdBuilder.AppendLine("SET @TempStr = CONVERT(VARCHAR ,@Counter) ;")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("IF (LEN(@TempStr) < @Temp)")
        cmdBuilder.AppendLine("   SET @TempStr = REPLICATE('0' ,@Temp - LEN(@TempStr)) + @TempStr ;")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("SET @TempStr = @IDPrefix + @TempStr ;")
        cmdBuilder.AppendLine()
        cmdBuilder.AppendLine("SELECT @TempStr ;")

        Using myConnection As System.Data.SqlClient.SqlConnection = New System.Data.SqlClient.SqlConnection(varConnectionString)

            Dim myCmd As System.Data.SqlClient.SqlCommand = New System.Data.SqlClient.SqlCommand(cmdBuilder.ToString(), myConnection)
            Try
                myConnection.Open()
                iStr = myCmd.ExecuteScalar().ToString()
            Catch ex As Exception
                iStr = "#Error"
            End Try
        End Using

        Return iStr

    End Function

public string GetNewEmployee_ID(string varConnectionString)
{

	string iStr = string.Empty;
	System.Text.StringBuilder cmdBuilder = new System.Text.StringBuilder();

	cmdBuilder.AppendLine("DECLARE @Counter          AS BIGINT ;");
	cmdBuilder.AppendLine("DECLARE @MaxCounter       AS BIGINT ;");
	cmdBuilder.AppendLine("DECLARE @Temp             AS INT ;");
	cmdBuilder.AppendLine("DECLARE @IDPrefix         AS Varchar(10);");
	cmdBuilder.AppendLine("DECLARE @TempStr          AS Varchar(MAX);");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("SET @IDPrefix = 'EMP-' ;");
	cmdBuilder.AppendLine("SET @Counter = 0 ;");
	cmdBuilder.AppendLine("SET @MaxCounter = 999999999999 ;");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("SELECT @TempStr = MAX([Employee_id]) FROM [Employee] ;");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("IF (LEN(@TempStr)>0) ");
	cmdBuilder.AppendLine("BEGIN");
	cmdBuilder.AppendLine("   SET @TempStr = SUBSTRING(LEN(@IDPrefix) +1,LEN(@TempStr));");
	cmdBuilder.AppendLine("   SET @Counter = CONVERT(BIGINT ,@TempStr) ;");
	cmdBuilder.AppendLine("END ");
	cmdBuilder.AppendLine("ELSE");
	cmdBuilder.AppendLine("   SET @Counter = 0 ;");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("SET @Counter = @Counter +1 ;");
	cmdBuilder.AppendLine("IF (@Counter > @MaxCounter)");
	cmdBuilder.AppendLine("   SET @Counter = 1 ;");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("-- FORMAT DATA FOR OUTPUT");
	cmdBuilder.AppendLine("SET @Temp = LEN(@MaxCounter) ;");
	cmdBuilder.AppendLine("SET @TempStr = CONVERT(VARCHAR ,@Counter) ;");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("IF (LEN(@TempStr) < @Temp)");
	cmdBuilder.AppendLine("   SET @TempStr = REPLICATE('0' ,@Temp - LEN(@TempStr)) + @TempStr ;");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("SET @TempStr = @IDPrefix + @TempStr ;");
	cmdBuilder.AppendLine();
	cmdBuilder.AppendLine("SELECT @TempStr ;");

	using (System.Data.SqlClient.SqlConnection myConnection = new System.Data.SqlClient.SqlConnection(varConnectionString)) {

		System.Data.SqlClient.SqlCommand myCmd = new System.Data.SqlClient.SqlCommand(cmdBuilder.ToString(), myConnection);
		try {
			myConnection.Open();
			iStr = myCmd.ExecuteScalar().ToString();
		} catch (Exception ex) {
			iStr = "#Error";
		}
	}

	return iStr;

}