Question

我有一个从我的数据库中检索数据的转发器。由于以下原因，某些结果在特定列中获取空值一个连接查询及其罚款。

我想查看每一行，如果结果为null，则具体为null 我想要改变这一行的CSS。

现在代码：

<asp:Repeater ID="repRequests" OnItemDataBound="repRequests_ItemDataBound" runat="server">
    <ItemTemplate>
        <asp:Label ID="lbltest" runat="server" Text='<%#Eval("val_name") %>'></asp:Label>
    </ItemTemplate>
</asp:Repeater>

C＃：

if (!IsPostBack)
{
    using (SqlConnection con = new SqlConnection(CS))
    {
        SqlCommand cmd = new SqlCommand("check_accepted", con);
        cmd.CommandType = System.Data.CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@val_name", Session["valName"].ToString());
        con.Open();
        SqlDataReader dr = cmd.ExecuteReader();

        repRequests.DataSource = dr;
        repRequests.DataBind();
    }
}

如何写这个？

protected void repRequests_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || 
        e.Item.ItemType == ListItemType.AlternatingItem)
    {
        **//what i want to get:**

        if (dr["accepted_id"] == Null) // a column from the db table
        {
            repRequests.attribute["class"] = "Some Class"
        }
    }
}

感谢帮助者！

Answer 1

您可以尝试以下操作。如果数据源是DataReader对象，则必须将e.Item.DataItem转换为DBDataRecord类型（来自System.Data.Common）

protected void repRequests_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item ||
        e.Item.ItemType == ListItemType.AlternatingItem)
    {
        System.Data.Common.DbDataRecord dataRow = e.Item.DataItem as System.Data.Common.DbDataRecord;
        if (dataRow["accepted_id"] == DBNull.Value || dataRow["accepted_id"] == null) // a column from the db table
        {
          // I am not sure how to you get repRequests. but you can find the control using e.Row.Item.FindControl() function
           repRequests.attribute["class"] = "Some Class";
        }
    }
}

修改除了您的问题之外，如果您想要更改特定行的css，如果某个值为null，则无法直接将css设置为转发器或转发器项。您需要做的是将一个顶级面板添加到ItemTemplate中，如下所示

<ItemTemplate> <asp:Panel runat="server" ID="panelRow"> <asp:Label ID="lbltest" runat="server" Text='<%#Eval("val_name") %>'></asp:Label> </asp:Panel> </ItemTemplate>

然后你可以改变面板的css，如下所示

protected void repRequests_ItemDataBound(object sender, RepeaterItemEventArgs e) { if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem) { System.Data.Common.DbDataRecord dataRow = e.Item.DataItem as System.Data.Common.DbDataRecord; if (dataRow["accepted_id"] == DBNull.Value || dataRow["accepted_id"] == null) // a column from the db table { Panel panelRow = e.Item.FindControl("panelRow") as Panel; panelRow.CssClass = "yourcssclass"; } } }

Answer 2

当您使用sqldatareader绑定转发器控件时，这是DbDataRecord的{{1}}示例。

另请注意repRequests.attribute["class"] = "Some Class"这意味着您将CSS Class应用于转发器控件。您需要更改用作转发器控件项的CssClass标签。

protected void repRequests_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || 
         e.Item.ItemType == ListItemType.AlternatingItem)
    {
         DbDataRecord dbr = (DbDataRecord)e.Item.DataItem;
         if( Convert.ToString(DataBinder.Eval(dbr, "accepted_id")) == null )
             ((Label)e.Item.FindControl("lbltest")).CssClass = "Some Class";
    }
}

Answer 3

如果没有，您可以在查询中使用IsNull。

SqlCommand cmd = new SqlCommand("select IsNull(something,zero) from sometable",connectionstring)
SqlDatareader dr = cmd.ExecuteReader();
while(dr.Read())
{
   if(dr.GetString(0)=="zero")
   {
        repRequests.attribute["class"] = "Some Class";
   }
}

每行的asp.net转发器

3 个答案: