ASP.NET GriewView更新为什么会出错?

Question

数据库表Banner中有两具字段:Position和URL，现在我想做更改Gridview中URL字段的功能：    <form id="form1" runat="server">
    <div>
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="AccessDataSource1" AutoGenerateEditButton="true" >
        <Columns>
        <asp:BoundField DataField="Position" ReadOnly="true" />
        <asp:ImageField DataImageUrlField="URL"  /> 
        <asp:CommandField EditText="EditText" UpdateText="UpdateText" SelectText="SelectText" />
        </Columns>
        </asp:GridView>    
        <asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="/App_Data/heart.mdb"
            SelectCommand="SELECT * FROM [Banner]" UpdateCommand="Update [Banner] set URL=@URL where Position=@Position "></asp:AccessDataSource>
    </div>
    </form>
点“编辑”“更新”报出错“至少一个参数没有被指定值。 ”是怎么回事？

Answer 1

UpdateCommand="Update [Banner] set URL=@URL where Position=@Position "
你的数据源控件不对。重新添加数据源控件吧。

Answer 2

        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataSourceID="AccessDataSource2" AutoGenerateEditButton="True" DataKeyNames="Position" >
        <Columns>
            <asp:BoundField DataField="Position" HeaderText="Position" ReadOnly="True" SortExpression="Position" />
            <asp:BoundField DataField="URL" HeaderText="URL" SortExpression="URL" />
        </Columns>
        </asp:GridView>    &nbsp;
        <asp:AccessDataSource ID="AccessDataSource2" runat="server" DataFile="/App_Data/heart.mdb" SelectCommand="SELECT * FROM [Banner]" 
        UpdateCommand="UPDATE [Banner] SET URL =@URL Where Position=@Position">
            <UpdateParameters>
                <asp:ControlParameter ControlID="GridView1" Name="URL"  />
                <asp:ControlParameter ControlID="GridView1" Name="Position"  />
            </UpdateParameters>
        </asp:AccessDataSource>
上面的代码，数据的显示是没问题了，但是更新还是报错：
“操作必须使用一个可更新的查询”

Answer 3

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True"  OnRowEditing="GridView_RowEditing" OnRowUpdating ="GridView_RowUpdating" OnRowCancelingEdit="GridView_RowCancelingEdit" 
            AutoGenerateColumns="False" BackColor="Transparent" DataKeyNames="Id" OnRowDataBound="GridView1_RowDataBound" OnSorting="GridView1_Sorting" Width="682px" style="text-align: left" ShowFooter="True">
  <Columns>
      <asp:BoundField DataField="Id" HeaderText="Id" InsertVisible="False" ReadOnly="True" SortExpression="Id" Visible="False" />
........
    Protected Sub GridView1_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
        GridView1.EditIndex = e.NewEditIndex
        bind()
    End Sub  '编辑
    Protected Sub GridView_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
       
更新代码...
    End Sub  '更新    Protected Sub GridView1_RowCancelingEdit(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
        GridView1.EditIndex = -1
        bind()
    End Sub  '取消