updating data in boundfield (Input string was not in a correct format.)

Question

I have a viewproducts page and what I want is when clicking on the edit link, two fields will be edited (Name and Price). here is my html code:

<ItemTemplate>
        <asp:LinkButton ID="LinkButton1" Text="Edit" runat="server" CommandName="Edit" />
    </ItemTemplate>
    <EditItemTemplate>
        <asp:LinkButton ID="LinkButton2" Text="Update" runat="server" OnClick="OnUpdate" />
        <asp:LinkButton ID="LinkButton3" Text="Cancel" runat="server" OnClick="OnCancel" />
    </EditItemTemplate>
</asp:TemplateField>

and code behind:

private void GetProducts(int CategoryID)
    {
        ShoppingCart k = new ShoppingCart()
        {
            CategoryID = CategoryID
        };
        gdview.DataSource = null;
        gdview.DataSource = k.GetAllProducts();
        gdview.DataBind();
    }
    protected void OnRowEditing(object sender, GridViewEditEventArgs e)
    {
        gdview.EditIndex = e.NewEditIndex;
        this.GetProducts(0);
    }
    protected void OnUpdate(object sender, EventArgs e)
    {
        GridViewRow row = (sender as LinkButton).NamingContainer as GridViewRow;
        string Name = (row.Cells[0].Controls[0] as TextBox).Text;
        string Price = (row.Cells[2].Controls[0] as TextBox).Text;
        DataTable dt = ViewState["dt"] as DataTable;
        dt.Rows[row.RowIndex]["Name"] = Name;
        dt.Rows[row.RowIndex]["Price"] = Price;
        ViewState["dt"] = dt;
        gdview.EditIndex = -1;
        this.GetProducts(0);
    }

    protected void OnCancel(object sender, EventArgs e)
    {
        gdview.EditIndex = -1;
        this.GetProducts(0);
    }
    protected void gdview_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {

            if (Convert.ToInt32(e.Row.Cells[6].Text) < 50)
            {
                e.Row.Cells[0].BackColor = System.Drawing.Color.Red;
                e.Row.Cells[0].ForeColor = System.Drawing.Color.White;
                e.Row.Cells[6].BackColor = System.Drawing.Color.Red;
                e.Row.Cells[6].ForeColor = System.Drawing.Color.White;
            }
        }
    }

However it gives me an error saying: Input string was not in a correct format. and the red text is with:

if (Convert.ToInt32(e.Row.Cells[6].Text) < 50)

what am I missing here?

here is the gridview code:

<Columns>


        <asp:BoundField HeaderText="Name" DataField="Name" SortExpression="Name" >
            <ItemStyle Height="20px" Width="150px" />
        </asp:BoundField>

        <asp:BoundField HeaderText="ProductCategory " ReadOnly="true" DataField="CategoryName" SortExpression="CategoryNaame" >
            <ItemStyle Height="20px" Width="150px"  />
        </asp:BoundField>

        <asp:BoundField HeaderText="Price" DataField="Price" SortExpression="Price" >
            <ItemStyle Height="20px" Width="150px" />
        </asp:BoundField>

        <asp:ImageField HeaderText ="ImageUrl" DataImageUrlField="ImageUrl" SortExpression="ImageUrl" ReadOnly="true" ControlStyle-Width ="10">

        <ControlStyle Width="50px"></ControlStyle>

        </asp:ImageField>

        <asp:BoundField HeaderText="ProductQuantity" DataField="ProductQuantity" ReadOnly="true" SortExpression="ProductQuantity" >
            <ItemStyle Height="20px" Width="150px" />
        </asp:BoundField>

        <asp:BoundField HeaderText="ProductSold" DataField="ProductSold" SortExpression="ProductSold" ReadOnly="true" >
            <ItemStyle Height="20px" Width="150px" />
        </asp:BoundField>

        <asp:BoundField HeaderText="AvailableStock" DataField="AvailableStock" SortExpression="AvailableStock " ReadOnly="true" >
            <ItemStyle Height="20px" Width="150px" />
        </asp:BoundField>

The name field disappears when the textbox for edit is visible?

Answer 1

The text in cell is empty which can't be converted to int so put a check if text in not empty than convert it to int

if(!string.IsNullOrEmpty(e.Row.Cells[6].Text))

If you don't want to make a column editable set the property ReadOnly="true"

ReadOnly="true"

For example if you want to set this coulmn ReadOnly="true"

<asp:BoundField HeaderText="Name" DataField="Name" SortExpression="Name" ReadOnly="true">
   <ItemStyle Height="20px" Width="150px" />
</asp:BoundField>