[nooralcown]

Dim CmdInsert As New SqlCommand
        With CmdInsert
            .Connection = Con
            .CommandType = CommandType.Text
            .CommandText = "Insert Into store_id (num , date , mowared , senfnum , q1 , q2 , price , currencey , currenceyrate , stornum)values( @num ,  @date ,  @mowared ,  @senfnum ,  @q1 ,  @q2 ,  @price ,  @currencey ,  @currenceyrate ,  @stornum)"
            .Parameters.Clear()
            For i As Integer = 0 To (DataGridView1.Rows.Count - 1)
                .Parameters.AddWithValue("@num", SqlDbType.Int).Value = Val(TextBox1.Text)
                .Parameters.AddWithValue("@date", SqlDbType.Date).Value = Dtpdate.Value
                .Parameters.AddWithValue("@mowared", SqlDbType.Int).Value = Val(TextBox2.Text)
                .Parameters.AddWithValue("@senfnum", SqlDbType.Int).Value = DataGridView1(0, i).Value.ToString
                .Parameters.AddWithValue("@q1", SqlDbType.Decimal).Value = DataGridView1(2, i).Value.ToString
                .Parameters.AddWithValue("@q2", SqlDbType.Decimal).Value = DataGridView1(3, i).Value.ToString
                .Parameters.AddWithValue("@price", SqlDbType.Decimal).Value = DataGridView1(6, i).Value.ToString
                .Parameters.AddWithValue("@currencey", SqlDbType.Int).Value = Val(TextBox9.Text)
                .Parameters.AddWithValue("@currenceyrate", SqlDbType.Decimal).Value = Val(TextBox10.Text)
                .Parameters.AddWithValue("@stornum", SqlDbType.Int).Value = DataGridView1(4, i).Value.ToString
            Next

            ' Try
            If Con.State = 1 Then Con.Close()
            Con.Open()
            CmdInsert.ExecuteNonQuery()
            Con.Close()
            MsgBox("تم إضافة السجل بنجاح", MsgBoxStyle.Information, "حفظ")
            CmdInsert = Nothing
            ' Catch ex As Exception
            ' 'Con.Close()
            '  MsgBox(Err.Description, MsgBoxStyle.Information)
            '  Finally
            If Con.State = ConnectionState.Open Then Con.Close()
        End With
        '   End Try

الخطا الذي يخرج يقول  

The variable name '@num' has already been declared. Variable names must be unique within a query batch or stored procedure.