根据数据值在下拉菜单中设置所选项目 [英] Setting selected item in a dropdown based on data value

问题描述

我正在设置一个页面来显示基于联赛的比赛结果，并且系统存储了多个赛季的结果.

我有一个表(tblSeason)，其中存储SeasonID，SeasonName和一个称为Current的位字段-仅设置了一条记录-这是结果的默认季节-这使我可以获取历史数据，当前季节和未来季节.我想填充一个下拉列表，将当前季节作为默认选择.

填充下拉列表很容易，但是我无法弄清楚如何预先选择当前季节.

季节表中的数据是这样的

SeasonID，季节，当前
1，"2010/11"，0
2，"2011/12"，0
3，"2012/13"，1
4，"2013/14"，0

我使用的SQL字符串是:
从[tblSeason]中选择[SeasonID]，[Season]，[Current]，然后按[Season]排序

下拉列表的标记为:

< asp:DropDownList ID ="ddlSeason" runat ="server" DataSourceID ="sqlSeason"
DataTextField ="Season" DataValueField ="SeasonID"
AutoPostBack ="True" onselectedindexchanged ="ddlLeague_SelectedIndexChanged">


由于我要查找的数据中的值不在下拉列表的文本或值属性中，因此无法使用FindByValue或FindByText方法.我该怎么做?

I am setting up a page to display results from a league based competition, and the system stores results for numerous seasons.

I have a table (tblSeason) that stores SeasonID, SeasonName and a bit field called Current - only one record has the bit set - it is the default season for the results - this allows me to have historic data, the current season, and future seasons. I want to populate a drop down list, with the current season as the default selection.

Populating the dropdown is easy, but I can''t work out how to pre-select the current season.

Data in the season table is like this

SeasonID, Season, Current
1,"2010/11",0
2,"2011/12",0
3,"2012/13",1
4,"2013/14",0

The SQL string I use is:
SELECT [SeasonID], [Season], [Current] FROM [tblSeason] ORDER BY [Season]

The markup for the dropdown list is:

<asp:DropDownList ID="ddlSeason" runat="server" DataSourceID="sqlSeason"
DataTextField="Season" DataValueField="SeasonID"
AutoPostBack="True" onselectedindexchanged="ddlLeague_SelectedIndexChanged">


As the value in the data that I am looking for is not in the text or value propert of the dropdown, I can''t use the FindByValue or FindByText methods. How can I do this?

推荐答案

尝试以下代码:

Try following code:

ddlSeason.SelectedIndex = ddlSeason.Items.IndexOf(ddlSeason.Items.FindByValue("4"));

希望对您有帮助.

〜Amol

Hope this will help you.

~Amol

我创建了一个过程来检索设置了Current标记的seaon，然后将此值与下拉菜单的FindByText方法一起使用:

I created a procedure to retrieve the seaon that has the Current marker set, then used this value with the FindByText method of the dropdown:

string strCurrent = getCurrentSeason();
          ddlSeason.SelectedIndex = ddlSeason.Items.IndexOf(ddlSeason.Items.FindByText(strCurrent));

protected string getCurrentSeason()
       {

           SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString);
           conn.Open();
           string queryString = "SELECT [Season] FROM tblSeason WHERE [Current] = 1";
           SqlCommand command = new SqlCommand(queryString, conn);
           string strReturn = "";

           SqlDataReader reader = null;
           reader = command.ExecuteReader();

           if (reader.Read())
           {
              strReturn = reader.GetString(0);
           }
           reader.Close();
           reader.Dispose();
           conn.Close();
           conn.Dispose();
           return strReturn;

       }

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