按下“编辑链接”按钮后，仅某些列可以更新，其余列设置为null

Question

When you select the "Edit" button the first two columns: idt and datetime allows you to update.

(as long as the Primary Key is Unique)

The last three columns:col1, col2, and col3 come up null no matter what you enter before clicking "Update".

Here is the error code after entering "Update":

System.FormatException: Input string was not in a correct format.

Here is my code:

 <asp:GridView ID="GridView1" 
    runat="server"
    DataSourceID="SqlDataSource1"
    AutoGenerateColumns="false"
    DataKeyNames="idt" 
    AutoGenerateEditButton="true" 
    AutoGenerateDeleteButton="true"
    showfooter="true">
    <Columns>
        <asp:BoundField DataField="idt" HeaderText="idt" Readonly="true" SortExpression="idt" />
        <asp:BoundField DataField="datetime" HeaderText="datetime" SortExpression="datetime" />
        <asp:TemplateField SortExpression="col1" HeaderText="col1">
                <ItemTemplate>
                    <asp:TextBox ID="txt1" runat="server" Text='<%# Eval("col1") %>' />
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:textbox id="col1TextBox" text='<%#Eval("col1")%>' runat="server" />
                </EditItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField SortExpression="col2" HeaderText="col2">
                <ItemTemplate>
                    <asp:TextBox ID="txt2" runat="server" Text='<%# Eval("col2") %>' />
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:textbox id="col2TextBox" text='<%#Eval("col2")%>' runat="server" />
                </EditItemTemplate>
            </FooterTemplate>
        </asp:TemplateField>
        <asp:TemplateField SortExpression="col3" HeaderText="col3">
                <ItemTemplate>
                    <asp:TextBox ID="txt3" runat="server" Text='<%# Eval("col3") %>' />
                </ItemTemplate>
                <EditItemTemplate>
                    <asp:textbox id="col3TextBox" text='<%#Eval("col3")%>' runat="server" />
                </EditItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<asp:SqlDataSource
    id="SqlDataSource1"
    ConnectionString="<%$ ConnectionStrings:Total %>"
    SelectCommand="SELECT * FROM [test];"
    UpdateCommand="UPDATE [test] SET [datetime] = @datetime, [col1] = @col1, [col2] = @col2, [col3] = @col3 WHERE [idt] = @idt;"
    DeleteCommand="DELETE FROM [test] WHERE [idt] = @idt;"
    runat="server">
    <DeleteParameters>
        <asp:Parameter Name="idt" Type="Int32" />
    </DeleteParameters>
    <UpdateParameters>
        <asp:Parameter Name="idt" Type="Int32" />
        <asp:Parameter Name="datetime" Type="String" />
        <asp:Parameter Name="col1" Type="Int32" />
        <asp:Parameter Name="col2" Type="Int32" />
        <asp:Parameter Name="col3" Type="Int32" />
    </UpdateParameters>    </asp:SqlDataSource>

Answer 1

I think Bind should be used instead of Eval. As Bind is for two way databinding and used when you want to edit or insert.