我的命令参数返回";每一次

本文关键字：一次 我的 参数 返回 quot 命令 | 更新日期: 2023-09-27 18:15:47

每当我点击其中一个删除链接按钮时，e.c remand参数总是保留"的值。我在某个地方读到你不能在命令参数中使用<%#，但我已经看到了几个例子，这是有效的。有什么建议吗?

在ASPX 

 <asp:DataList ID="DataList1" runat="server" DataSourceID="SqlDataSource1">
        <ItemTemplate>
            <asp:Label ID="dataLabel" runat="server" Text='<%# Eval("data") %>' />
            <br />
            <asp:Label ID="nameLabel" runat="server" Text='<%# Eval("name") %>' />
            &nbsp;|&nbsp;
            <asp:Label ID="Column1Label" runat="server" Text='<%# Eval("Column1") %>' />
            <br />
            <asp:LoginView ID="HeadLoginView" runat="server" EnableViewState="false">
            <LoggedInTemplate>
                <asp:LinkButton CLASS="DeleteButton" runat="server" OnCommand="Delete" CommandArgument='<%# Eval("id") %>' ViewStateMode="Disabled">Delete</asp:LinkButton>
            </LoggedInTemplate>
            </asp:LoginView>
        </ItemTemplate>
    </asp:DataList>
    <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
        ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" 
            SelectCommand="SELECT [id],[name], [data], convert(varchar, [date], 101) FROM [Announcements] ORDER BY [date] DESC">
    </asp:SqlDataSource>
在ASPX.CS 

using (SqlConnection conn = new SqlConnection(WebConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString))
        {
            SqlCommand command = conn.CreateCommand();
            command.CommandText = "DELETE FROM Annoucnements WHERE id=@id";
            command.CommandType = System.Data.CommandType.Text;
            command.Parameters.Add(new SqlParameter("id", e.CommandArgument));
            conn.Open();
            command.ExecuteNonQuery();
        }

根据Royi Namir的建议，将EnableViewState更改为true可以解决这个问题。

我的命令参数返回";每一次

在寻找了一点之后，我发现了一些帖子，说你不能在服务器标签内使用<%# ... %>语法，这显然是错误的，因为你正在使用它的Text属性，我敢肯定我以前做过同样的事情。无论如何，您可以在DataList上使用ItemDataBound事件:

 <asp:DataList ID="DataList1" runat="server" DataSourceID="SqlDataSource1" OnItemDataBound="DataList1_ItemDataBound">
        <ItemTemplate>
            <asp:Label ID="dataLabel" runat="server" Text='<%# Eval("data") %>' />
            <br />
            <asp:Label ID="nameLabel" runat="server" Text='<%# Eval("name") %>' />
            &nbsp;|&nbsp;
            <asp:Label ID="Column1Label" runat="server" Text='<%# Eval("Column1") %>' />
            <br />
            <asp:LoginView ID="HeadLoginView" runat="server" EnableViewState="false">
            <LoggedInTemplate>
                <asp:LinkButton CssClass="DeleteButton" runat="server" ID="lbDelete" OnCommand="Delete" CommandArgument='<%# Eval("id") %>' ViewStateMode="Disabled">Delete</asp:LinkButton>
            </LoggedInTemplate>
            </asp:LoginView>
        </ItemTemplate>
    </asp:DataList>
    <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
        ConnectionString="<%$ ConnectionStrings:ApplicationServices %>" 
            SelectCommand="SELECT [id],[name], [data], convert(varchar, [date], 101) FROM [Announcements] ORDER BY [date] DESC">
    </asp:SqlDataSource>

请注意，我已经将ID="lbDelete"添加到您的LinkButton(并将CLASS更改为CssClass)，这需要在我们的代码中找到控件:

protected void DataList1_ItemDataBound(object sender, DataListItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) // this is to ensure that we're looking in an item that will contain controls, and not the header or footer
    {
        LoginView headLoginView = (LoginView)e.Item.FindControl("HeadLoginView") // FindControl is not recursive so we need a reference to a control we can look in to find the button
        LinkButton lbDelete = (LinkButton)headLoginView.FindControl("lbDelete");
        if (lbDelete != null) // check for a null otherwise this code will fail if the user is not logged in, because the controls inside the LoggedInTemplate will not be rendered
        {
            lbDelete.CommandArgument = DataBinder.Eval(e.Item.DataItem, "id").ToString(); // set the CommandArgument on the button using DataBinder.Eval
        }
    }
}

您只需要DataKeyField唯一标识您的行，以便执行Delete操作。

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