求帮忙：输入字符串的格式不正确。

Question

public partial class shoppingCart : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            bindData();
        }
    }
    private void bindData()
    {
        gdvCart.DataSource = (DataTable)Session["shoppingCart"];
        gdvCart.DataBind();
    }
    protected void gdvCart_RowCommand(object sender, GridViewCommandEventArgs e)
    {
        //if (e.CommandName == "delete")
        //{
        //    int index = Convert.ToInt32(e.CommandArgument);
        //    //GridViewRow row = GridView1.Rows[index];
        //    //int bid = Convert.ToInt32(row.Cells[2].Text);        //    DataTable dt = (DataTable)Session["shoppingCart"];
        //    //delete one row
        //    dt.Rows.RemoveAt(index);        //    //save again
        //    Session["shoppingCart"] = dt;
        //    bindData();
        //}        DataTable cart = new DataTable();        if (Session["shoppingCart2"] == null)
        {
            cart.Columns.Add("bookID", typeof(int));
            cart.Columns.Add("bookName", typeof(string));
            cart.Columns.Add("quantity", typeof(int));
            cart.Columns.Add("price", typeof(double));
            cart.Columns.Add("buyTime", typeof(DateTime));
            Session["shoppingCart2"] = cart;
        }        cart = (DataTable)Session["shoppingCart2"];        int index = Convert.ToInt32(e.CommandArgument);
        GridViewRow row = gdvCart.Rows[index];
        DataRow rr = cart.NewRow();        rr["bookID"] = Convert.ToInt32(row.Cells[2].Text);
        rr["bookName"] = Convert.ToString(row.Cells[3].Text);
        TextBox tt = (TextBox)row.Cells[1].FindControl("txtQuan");
        rr["quantity"] = Convert.ToInt32(tt.Text);
       rr["price"] = Convert.ToDouble(row.Cells[4].Text);
        rr["buyTime"] = Convert.ToDateTime(row.Cells[5].Text);        cart.Rows.Add(rr);
        Session["shoppingCart2"] = cart;
    }
    protected void btnBuy_Click(object sender, EventArgs e)
    {
        //invalid customer
        if (Session["userID"] == null)
        {
            Response.Write("<script>window.alert('抱歉，只有登录系统才可以结账！')</script>");
            Session["shoppingCart"] = null;
        }
        //valid customer
        else
        {
            Response.Redirect("buyCenter.aspx");
        }
    }
}

Answer 1

row.Cells[4].Text的文本无法转换成double，确认它是一个合法的数字。

Answer 2

按照你的数据定义，Cells[3]才是price值啊，因为Cells是从0开始的索引

Answer 3

对，Cells[3]才对，报这个错表示源文本不是数字格式的字符串。

Answer 4

哈哈，好了，谢谢你的提示
rr["price"] = Convert.ToDouble(row.Cells[4].Text);
rr["buyTime"] = Convert.ToDateTime(row.Cells[5].Text);
改为rr["price"] = Convert.ToDouble(row.Cells[5].Text);
        rr["buyTime"] = Convert.ToDateTime(row.Cells[7].Text);