Question

我写了一个代码，向客户展示saleresult。但最后，我想要所有的价格和显示总价格的标签。但是我在这个步骤失败了，我给出了＃34;输入字符串的格式不正确。＆＃34;来自视觉工作室。这个问题是什么？

    protected void Page_Load(object sender, EventArgs e)
{


    /////Fetching Reservation Date and Reservation Time
    using (SqlConnection connection3 = DBConnection.getConnection())
    {
        string strquery3 = "SELECT SaloonReservationDate,SaloonReservationTime  FROM SaloonGeneralReservation";
        connection3.Open();
        SqlCommand cmd3 = new SqlCommand();
        cmd3.Connection = connection3;
        cmd3.CommandText = strquery3;
        SqlDataReader reader3 = cmd3.ExecuteReader();
        if (reader3.Read())
        {
           lbl4_ResDate.Text = reader3[0].ToString();
           lbl6_ResTime.Text = reader3[1].ToString();

        }
    }


    /////Fetching Service Prices
    using (SqlConnection connection2 = DBConnection.getConnection())
    {
        //query for fetch service prices 
        string strquery2 = "SELECT Fruit_price,Drink_price,Desert_price,MainFood_price,Salad_price,TableFlower_price,SaloonLighting_price,SaloonDesign_price,SaloonCrew_price,Pastry_price,GiftCard_price  FROM GenReservationServicePrice";
        connection2.Open();
        SqlCommand cmd2 = new SqlCommand();
        cmd2.Connection = connection2;
        cmd2.CommandText = strquery2;
        SqlDataReader reader1 = cmd2.ExecuteReader();
        if (reader1.Read())
        {                               
            Fruit_price = reader1[0].ToString();
            Drink_price = reader1[1].ToString();
            Desert_price = reader1[2].ToString();
            MainFood_price = reader1[3].ToString();
            Salad_price = reader1[4].ToString();
            TableFlower_price = reader1[5].ToString();
            SaloonLighting_price = reader1[6].ToString();
            SaloonDesign_price = reader1[7].ToString();
            SaloonCrew_price = reader1[8].ToString();
            Pastry_price = reader1[9].ToString();
            GiftCard_price = reader1[10].ToString();

        }
    }


    /////Fetching Selected Items by User
    using (SqlConnection connection1 = DBConnection.getConnection())
    {          
        string strquery1 = "SELECT (select top 1 'Fruit' FROM WeedingSalonGeneralRes where Fruit=1) as fruit, (select top 1 'Drink' FROM WeedingSalonGeneralRes where Drink=1) as drink, (select top 1 'Desert' FROM WeedingSalonGeneralRes where Desert=1) as desert,(select top 1 'MainFood' FROM WeedingSalonGeneralRes where MainFood=1) as MainFood,(select top 1 'Salad' FROM WeedingSalonGeneralRes where Salad=1) as salad,(select top 1 'TableFlower' FROM WeedingSalonGeneralRes where TableFlower=1) as TableFlower,(select top 1 'SaloonLighting' FROM WeedingSalonGeneralRes where SaloonLighting=1) as SaloonLighting,(select top 1 'Saloondesign' FROM WeedingSalonGeneralRes where Saloondesign=1) as Saloondesign,(select top 1 'SloonCrew' FROM WeedingSalonGeneralRes where SloonCrew=1) as SloonCrew,(select top 1 'Pastry' FROM WeedingSalonGeneralRes where Pastry=1) as Pastry,(select top 1 'GiftCard' FROM WeedingSalonGeneralRes where GiftCard=1) as GiftCard ";
        connection1.Open();
        SqlCommand cmd1 = new SqlCommand();
        cmd1.Connection = connection1;
        cmd1.CommandText = strquery1;
        string cis = Session["customerID"].ToString();
        lbl2_customerid.Text = cis;

        double totalcost;

        SqlDataReader reader2 = cmd1.ExecuteReader();
        if (reader2.Read())
        {
            if (reader2[0].ToString() != null && reader2[0].ToString() != "")
            lbl8_fruit.Text = reader2[0].ToString() + Fruit_price;



            if (reader2[1].ToString() != null && reader2[1].ToString() != "")
            lbl10_drink.Text = reader2[1].ToString()+Drink_price;


            if (reader2[2].ToString() != null && reader2[2].ToString() != "")
            lbl11_desert.Text = reader2[2].ToString()+Desert_price;

            if (reader2[3].ToString() != null && reader2[3].ToString() != "")
            lbl12_mainfood.Text = reader2[3].ToString()+MainFood_price;


            if (reader2[4].ToString() != null && reader2[4].ToString() != "")
            lbl13_salad.Text = reader2[4].ToString()+Salad_price;


            if (reader2[5].ToString() != null && reader2[5].ToString() != "")
            lbl14_tableflower.Text = reader2[5].ToString()+TableFlower_price;


            if (reader2[6].ToString() != null && reader2[6].ToString() != "")
            lbl15_saloonlighting.Text = reader2[6].ToString()+SaloonLighting_price;


            if (reader2[7].ToString() != null && reader2[7].ToString() != "")
            lbl16_saloondesign.Text = reader2[7].ToString()+SaloonDesign_price;


            if (reader2[8].ToString() != null && reader2[8].ToString() != "")
            lbl17_salooncrew.Text = reader2[8].ToString()+SaloonCrew_price;


            if (reader2[9].ToString() != null && reader2[9].ToString() != "")
            lbl18_pastry.Text = reader2[9].ToString()+Pastry_price;


            if (reader2[10].ToString() != null && reader2[10].ToString() != "")
            lbl19_giftcard.Text = reader2[10].ToString()+GiftCard_price;


            totalcost = Convert.ToDouble(lbl8_fruit.Text) + Convert.ToDouble(lbl10_drink.Text);
            lblTotalCost.Text = totalcost.ToString();


        }
    }
}

Answer 1

检查文本框中的有效数值，例如：

double fruit;
double drink;

if (Double.TryParse(lbl8_fruit.Text.Text.Trim(), out fruit) &&  Double.TryParse(lbl10_drink.Text.Text.Trim(), out drink) ) 
{
       totalcost = fruit + drink;
}
else
{
 //not valid numeric values
}

希望这有帮助！

Answer 2

看起来文字中包含空格。

totalcost = Convert.ToDouble(lbl8_fruit.Text.Trim()) + Convert.ToDouble(lbl10_drink.Text.Trim())

输入字符串的格式不正确

2 个答案: