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我使用 ajax 创建了一个自动完成文本框，效果很好。它基本上提供了房间代码列表。这是代码：

[System.Web.Script.Services.ScriptMethod()]
[System.Web.Services.WebMethod]
public static List<string> GetRoomList(string prefixText, int count)
{
  using (SqlConnection roomsConnection = new SqlConnection())
  {
     roomsConnection.ConnectionString = ConfigurationManager.ConnectionStrings["roomsConnectionString"].ConnectionString;
     using (SqlCommand roomsCommand = new SqlCommand())
     {
        roomsCommand.CommandText = "select Room, Site from tblRoom where Room like '%' + @SearchText + '%'";
        roomsCommand.Parameters.AddWithValue("@SearchText", prefixText);
        roomsCommand.Connection = roomsConnection;
        roomsConnection.Open();

        List<string> roomList = new List<string>();
        using (SqlDataReader roomReader = roomsCommand.ExecuteReader())
          {
              while (roomReader.Read())
              {
                  roomList.Add(roomReader["Room"].ToString());
              }
           }
           roomsConnection.Close();
           return roomList;
       }
    }
}

但是，我希望它根据用户在上一页中选择的选项生成此房间代码列表。有两种方法可以传递选项。一种是使用查询字符串。这是我写的代码：

[System.Web.Script.Services.ScriptMethod()]
[System.Web.Services.WebMethod]
public static List<string> GetRoomList(string prefixText, int count)
{
   using (SqlConnection roomsConnection = new SqlConnection())
   {
       roomsConnection.ConnectionString = ConfigurationManager.ConnectionStrings["roomsConnectionString"].ConnectionString;

       HttpRequest request = HttpContext.Current.Request;
       string site1 = request.QueryString["site"];

       using (SqlCommand roomsCommand = new SqlCommand())
       {
          roomsCommand.CommandText = "select Room, Site from tblRoom where Site = '" + site1 + "' AND Room like '%' + @SearchText + '%'";
          roomsCommand.Parameters.AddWithValue("@SearchText", prefixText);
          roomsCommand.Connection = roomsConnection;
          roomsConnection.Open();

          List<string> roomList = new List<string>();
          using (SqlDataReader roomReader = roomsCommand.ExecuteReader())
          {
             while (roomReader.Read())
               {
                   roomList.Add(roomReader["Room"].ToString());
               }
          }
          return roomList;
          roomsConnection.Close();
     }                    
   }             
 }

我没有收到任何错误，只是没有从查询字符串中存储“站点”。我已经在我页面的其他区域使用了它，它工作正常。

我希望它工作的另一种方式是使用 Page.PreviousPage。这又是我写的：

[System.Web.Script.Services.ScriptMethod()]
[System.Web.Services.WebMethod]
public static List<string> GetRoomList(string prefixText, int count)
{
   using (SqlConnection roomsConnection = new SqlConnection())
     {
        roomsConnection.ConnectionString = ConfigurationManager.ConnectionStrings["roomsConnectionString"].ConnectionString;
        if (Page.PreviousPage != null)
        {
            if (Page.PreviousPage.IsCrossPagePostBack == true)
            {
                string site1 = PreviousPage.getDropDownListSite.SelectedValue;

                using (SqlCommand roomsCommand = new SqlCommand())
                {
                        roomsCommand.CommandText = "select Room, Site from tblRoom where Site = '" + site1 + "' AND Room like '%' + @SearchText + '%'";
                        roomsCommand.Parameters.AddWithValue("@SearchText", prefixText);
                        roomsCommand.Connection = roomsConnection;
                        roomsConnection.Open();

                        List<string> roomList = new List<string>();
                        using (SqlDataReader roomReader = roomsCommand.ExecuteReader())
                        {
                            while (roomReader.Read())
                            {
                                roomList.Add(roomReader["Room"].ToString());
                            }
                        }
               return roomList;
               roomsConnection.Close();
               }           
          }
       }
    }
}

我根本无法让这段代码工作，因为它不喜欢 Page.PreviousPage。我收到错误

An object reference is required for the non-static filed, method, or property      'system.Web.UI.Page.PreviousPage.get'

但我不知道还能用什么。我尝试使用一个效果很好的会话变量，但如果我用户需要在同一个会话中再次使用该表单，它会保留最后一个值。

一旦我让各个组件工作，我打算给我们一个 if，else 语句。

有人能帮忙吗。我真的很感激。非常感谢

4

1 回答 1

0

比在 webmethod 中获取 querystring 参数更好的方法是将参数作为参数传输到 webmethod：

[System.Web.Script.Services.ScriptMethod()]
[System.Web.Services.WebMethod]
public static List<string> GetRoomList(string prefixText, int count, string site)
{
    ...
}

在调用页面上，您必须将查询字符串设置为 Page_Load 函数中的 contextKey。contextKey 可以传递给 web 方法，以便您可以在 webmethod 中访问此变量。

于 2013-10-23T16:18:42.060 回答