单击按钮时无法访问gridview控件中的文本框值

Question

I have taken 3 text-boxes in grid view. I want to access all the 3 text-boxes value in single label on button click event. ASP code:

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" CellPadding="4"
        CssClass="style1" ForeColor="#333333" GridLines="None" Height="342px" Width="548px">
        <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
        <Columns>
            <asp:BoundField ApplyFormatInEditMode="True" DataField="IName" HeaderText="Item Name" />
            <asp:BoundField DataField="Description" HeaderText="Description" />
            <asp:BoundField DataField="price" HeaderText="Price" />
            <asp:TemplateField>
                <HeaderTemplate>
                    <asp:Label ID="txtqty" runat="server" AutoPostBack="false" Text="Enter Quantity" />
                </HeaderTemplate>
                <ItemTemplate>
                    <asp:TextBox ID="txtqtys" runat="server" AutoPostBack="false" OnTextChanged="TextBox_Changed"/>
                </ItemTemplate>
            </asp:TemplateField>
            <asp:TemplateField>
                <HeaderTemplate>
                    <asp:Label ID="chkAll" runat="server" onclick="checkAll(this);" AutoPostBack="true"
                        OnCheckedChanged="CheckBox_CheckChanged" Text="Select" />
                </HeaderTemplate>
                <ItemTemplate>
                    <asp:CheckBox ID="chk" runat="server" onclick="Check_Click(this)" AutoPostBack="True"
                        OnCheckedChanged="CheckBox_CheckChanged" />
                </ItemTemplate>
            </asp:TemplateField>
        </Columns>
        <EditRowStyle BackColor="#999999" />
        <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
        <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
        <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
        <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
        <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
        <SortedAscendingCellStyle BackColor="#E9E7E2" />
        <SortedAscendingHeaderStyle BackColor="#506C8C" />
        <SortedDescendingCellStyle BackColor="#FFFDF8" />
        <SortedDescendingHeaderStyle BackColor="#6F8DAE" />
    </asp:GridView>
<asp:Label ID="lbltxtqty" runat="server" Text="txtqty" Visible="true"></asp:Label>
<asp:Button ID="btnsubmit" runat="server" Text="Submit" onclick="btnsubmit_Click" />

C# code:

protected void btnsubmit_Click(object sender, EventArgs e)
{
     if (!IsPostBack)
        {
            lbltxtqty.Visible = true;
            lbltxtqty.Text = ((TextBox)GridView1.Rows[0].FindControl("txtqtys")).Text;
        }
}

so please tell me the write code for it.

Answer 1

You are "Contradicting" your own aspx and code behind code. Why I am saying this is because, check you Label Mark-up & button click event handler:-

<asp:Label ID="lbltxtqty" runat="server" Text="txtqty" Visible="true"></asp:Label>

Here you are setting labels Visible property to true which is of no use because its by default true. Now, see your button click event you are trying to make it visible by using lbltxtqty.Visible = true; , So obviously your mark-up should first look like this:-

<asp:Label ID="lbltxtqty" runat="server" Text="txtqty" Visible="false"></asp:Label>

Because, you must be needing that when Page loads.

Now, comes your button click event. Do you know the Page Life Cycle of ASP.NET? When button click event is fired that's an obvious PostBack request so what is the Point of checking IsPostBack property there? Remove this code and it should work. Change your button click handler as follows:-

protected void btnsubmit_Click(object sender, EventArgs e)
{
    lbltxtqty.Visible = true;
    lbltxtqty.Text = ((TextBox)GridView1.Rows[0].FindControl("txtqtys")).Text;
}