Silverlight 4.0：使用 WebClient UploadStringAsync POST 请求到.Net 4 Webservice

Question

I'm trying to get this code to run:

Silverlight App xaml.cs:

private void SavePoiRequest(MyPushpin pin)
    {
        WebClient wc = new WebClient();
        wc.Headers["Content-Type"] = "application/x-www-form-urlencoded";
        wc.Encoding = Encoding.UTF8;
        wc.UploadStringCompleted += new UploadStringCompletedEventHandler((sender, e) =>
        {
            if (e.Error != null)
            {
                return;
            }
            AddressTextBox.Text = e.Result;
        });
        String name = pin.Name;
        String lat  = pin.Location.Latitude.ToString().Replace(",",".");
        String lng  = pin.Location.Longitude.ToString().Replace(",",".");
        String address = pin.Address;
        String photodesc = pin.PhotoDesc;
        String poistory = pin.Tag.ToString();
        StringBuilder sr = new StringBuilder();
        sr.Append("createpoi?name="+name+ "&lat=" + lat + "&lng=" + lng + "&adr=" + address     + "&desc=" + photodesc + "&story=" + poistory);
        String parameter = sr.ToString();
        wc.UploadStringAsync(new Uri("http://localhost:80/"), "POST", parameter);
        AddressTextBox.Text = parameter;
    }

Webservice cs:

[WebInvoke(UriTemplate = "createpoi?name={name}&lat={latitude}&lng={longitude}&adr={address}&desc={photodescription}&story={poistory}", Method = "POST")]
    public String SetPoiPOST(string name, string latitude, string longitude, string address, string photodescription, string poistory)
    {
        int newid = -1;
        POI_Man poimanager = new POI_Man();
        MemoryStream resultstream = new MemoryStream();

        if (!string.IsNullOrEmpty(name) &&
            !string.IsNullOrEmpty(latitude) &&
            !string.IsNullOrEmpty(longitude) &&
            !string.IsNullOrEmpty(address) &&                
            !string.IsNullOrEmpty(photodescription) &&
            !string.IsNullOrEmpty(poistory)
            )
        {
            //newid = poimanager.CreatePOI_alt(address, name, photodescription, poistory);
            newid = poimanager.CreatePOI(name, latitude, longitude, address, photodescription, poistory);
            poimanager.Generate("xml");
            resultstream = poimanager.WriteMessage(newid.ToString());
            WebOperationContext.Current.OutgoingResponse.ContentType = "text/plain";
        }

        if (poimanager.NoError)
        {
            resultstream = poimanager.WriteMessage(newid.ToString());
            WebOperationContext.Current.OutgoingResponse.ContentType = "text/plain";
            //resultstream = (this.GetPoi(newid.ToString()) as MemoryStream);
        }
        else
        {
            resultstream = poimanager.WriteMessage("Beim anlegen des POI ist ein Fehler aufgetreten."
                + Environment.NewLine + "Haben Sie einen Parameter vergessen?");
            WebOperationContext.Current.OutgoingResponse.ContentType = "text/plain";

        }
        return newid.ToString();
    }

The web service doesn't get nothing from the client. Am I doing something wrong?

I can contact the Server via a POST-request through WebClient OpenWriteAsync. But I need the response of the server for the lastID, so I use UploadStringAsync instead. Could you please help me?

Bye Chau

Answer 1

Try wc.UploadStringAsync(new Uri("http://localhost:80/createpoi"), "POST", parameters) and remember to urlencode your parameters

Answer 2

thx for the advice. I now know how the REST service works. It only reads the URL and not the parameters of the UploadStringAsync() function. So I rewrote the code and it works like a charm.

private void SavePoiRequest(MyPushpin pin)
    {
        WebClient wc = new WebClient();
        wc.Headers["Content-Type"] = "application/x-www-form-urlencoded";
        wc.Encoding = Encoding.UTF8;
        wc.UploadStringCompleted += new UploadStringCompletedEventHandler((sender, e) =>
        {
            if (e.Error != null)
            {
                return;
            }
            lastID = int.Parse(e.Result);
        });
        Uri baseAddressUri = new Uri("http://localhost:80/");
        UriTemplate uriTemplate = new UriTemplate("createpoi?name={name}&lat={latitude}&lng={longitude}&adr={address}&desc={photodesc}&story={poistory}");

        IDictionary<string, string> parameters = new Dictionary<string, string>();
        parameters.Add("name", pin.Name);
        parameters.Add("latitude", pin.Location.Latitude.ToString().Replace(",", "."));
        parameters.Add("longitude", pin.Location.Longitude.ToString().Replace(",", "."));
        parameters.Add("address", pin.Address);
        parameters.Add("photodesc", pin.PhotoDesc);
        parameters.Add("poistory", pin.Tag.ToString());
        Uri formattedUri = uriTemplate.BindByName(baseAddressUri, parameters);
        wc.UploadStringAsync(formattedUri, "POST");
    }