zone de liste déroulante Extjs Reliure de SQl

Question

Je suis nouveau à ExtJS, i utilisé dans asp.net, C# dans VS2008 .. i simplement ajouté le contrôle ComboBox avec des données statiques page ASPX,

mais je dois savoir lier la valeur de DB SQL, peut-on fournir une application de l'échantillon qui explique, comment obtenir la valeur de la commande et se lient aux commandes

Merci à l'avance

Answer 1

créer un gestionnaire HTTP générique, par exemple notre La liste des agences utilise ce code:

public void ProcessRequest(HttpContext context) 
{ 
     context.Response.ContentType = "text/javascript"; 
     context.Response.ContentEncoding = Encoding.UTF8; 

     // Get User ID 
     int user_id; 

     try { 
      user_id = int.Parse(context.Session["user_id"].ToString()); 
     } catch { 
      WriteErrorObject(context,"Could not find required user in the session."); 
      return; 
     } 

     // Get Query 
     string query; 

     try { 
      query = context.Request.QueryString["query"]; 

      if (String.IsNullOrEmpty(query)) throw new Exception(); 
     } catch { 
      query = ""; 
     } 

     // Get Revision 
     int revision; 

     try { 
      revision = int.Parse(ConfigurationManager.AppSettings["reportingRevision"]); 
     } catch { 
      revision = -1; 
     } 

     // Check for our connection string 
     try { 
      if (ConfigurationManager.ConnectionStrings["reportInstance"] == null) throw new Exception(); 
     } catch { 
      WriteErrorObject(context,"Cannot find the database connection string."); 
      return; 
     } 

     // Get our connection string 
     string connectionstring = ConfigurationManager.ConnectionStrings["reportInstance"].ConnectionString; 

     // Create our sproc caller 
     StoredProc proc; 

     try { 
      proc = new StoredProc("usp_rep2_agency_list",connectionstring,30); 
     } catch (Exception ex) { 
      WriteErrorObject(context,"There was an exception creating the stored procedure caller: " + ex.Message); 
      return; 
     } 

     // Set up sproc 
     if (revision != -1) proc.AddParameter("@revision",revision,SqlDbType.Int); 

     proc.AddParameter("@user_id",user_id,SqlDbType.Int); 

     if (query != null && query.Length > 0) proc.AddParameter("@query",query,SqlDbType.NVarChar); 

     // Execute sproc 
     DataSet results; 

     try { 
      results = (DataSet)proc.Execute(StoredProc.ExecuteTypes.ReturnDataset); 
     } catch (Exception ex) { 
      WriteErrorObject(context,"There was an exception calling the stored procedure: " + ex.Message); 
      return; 
     } 

     // Check we have results 
     if (results == null) { 
      WriteErrorObject(context,"There was no dataset returned from the stored procedure."); 
      return; 
     } 

     // Check we have a table 
     if (results.Tables.Count < 1) { 
      WriteErrorObject(context,"There was no tables found in the returned dataset from the stored procedure."); 
      return; 
     } 

     // Get the table 
     DataTable table = results.Tables[0]; 

     // Begin JSON 
     StringWriter writer = new StringWriter(); 
     JsonWriter json = new JsonWriter(writer); 

     json.WriteStartObject(); 
     json.WritePropertyName("success"); 
     json.WriteValue(true); 
     json.WritePropertyName("count"); 
     json.WriteValue(table.Rows.Count); 
     json.WritePropertyName("list"); 
     json.WriteStartArray(); 

     // Process table rows 
     for (int i = 0; i < table.Rows.Count; i++) { 
      // Get row 
      DataRow row = table.Rows[i]; 

      // ID 
      if (row["agency_id"] == null || row["agency_id"] == DBNull.Value) { 
       WriteErrorObject(context,"There was an error processing the agency id value from row " + i.ToString() + "."); 
       return; 
      } 

      int agency_id; 

      if (!int.TryParse(row["agency_id"].ToString(),out agency_id)) { 
       WriteErrorObject(context,"Could not parse the agency id value from row " + i.ToString() + "."); 
       return; 
      } 

      // Name 
      if (row["agency_name"] == null || row["agency_name"] == DBNull.Value) { 
       WriteErrorObject(context,"There was an error processing the agency name value from row " + i.ToString() + "."); 
       return; 
      } 

      string agency_name = row["agency_name"].ToString(); 

      // Write out JSON for this row 
      json.WriteStartObject(); 
      json.WritePropertyName("agency_id"); 
      json.WriteValue(agency_id); 
      json.WritePropertyName("agency_name"); 
      json.WriteValue(agency_name); 
      json.WritePropertyName("icon"); 
      json.WriteValue("iq-reporting-dropdowns-agency"); 
      json.WriteEndObject(); 
     } 

     // End JSON 
     json.WriteEndArray(); 
     json.WriteEndObject(); 

     string text = writer.GetStringBuilder().ToString(); 

     context.Response.Write(text); 
     context.Response.Flush(); 
} 

Ext-nous alors:

this.ddlAgency = new Ext.form.ComboBox({ 
     fieldLabel: "Agency", 
     mode: "remote", 
     triggerAction: "all", 
     forceSelection: true, 
     displayField: "agency_name", 
     valueField: "agency_id", 
     iconField: "icon", 
     typeAhead: true, 
     minChars: 1, 
     allowBlank: false, 
     anchor: "100%", 
     emptyText: "Select an Agency...", 
     store: new Ext.data.Store({ 
      autoLoad: false, 
      proxy: new Ext.data.HttpProxy({ 
       method: "GET", 
       url: "whatever.ashx" 
      }), 
      reader: new Ext.data.JsonReader(
       {root: "list", totalProperty: "count"}, 
       [{name: "agency_id", type: "int"},{name: "agency_name", type: "string"},{name: "icon", type: "string"}] 
      ), 
      baseParams: { 
       action: "agencylist", 
       level: 1 
      } 
     }) 
    }); 

Note, nous utilisons la bibliothèque 'Json.NET' pour gérer JSON et une classe personnalisée, 'StoredProc' faire l'interaction de base de données. Vous n'aurez pas non plus la méthode WriteErrorObject() qui sérialise simplement une erreur, mais vous avez l'idée.