Save image with webservice

Question

I already have a webservice for which I pass an image (Base64) and it saved on my server. So far it is working perfectly.

On my screen is this code :

function salvar() {
        var dados = {};

        //Utilizar o toDataURL para converter em Base64
        var base64 = document.getElementById("myCanvas").toDataURL("image/png");

        dados.base64 = base64.substr(base64.indexOf(',') + 1, base64.length);

        var WPath = "face1";

        $.ajax({
            type: 'POST',
            //Chamar o webmethod SalvarImagem em webservice.asmx
            url: "SalvarImagem.asmx/SalvarImagemX",
            contentType: 'application/json; charset=utf-8',
            dataType: 'json',
            data: JSON.stringify(dados, WPath),
            success: function (data) {
                alert(data.d);
            }
            , error: function (xmlHttpRequest, status, err) {
                alert("Ocorreu o seguinte erro:" + xmlHttpRequest.responseText)
            }
        });
    }

And my webservice is like this :

public class SalvarImagem : System.Web.Services.WebService
{

    [WebMethod]
    public string SalvarImagemX(string base64, string WPath)
    {
           //MemoryStream com o base64 recebido por parâmetro
        using (MemoryStream ms = new MemoryStream(Convert.FromBase64String(base64)))
        {
            //Criar um novo Bitmap baseado na MemoryStream
            using (Bitmap bmp = new Bitmap(ms))
            {
                //Local onde vamos salvar a imagem (raiz do site + /canvas.png)
                //string path = Server.MapPath("/" + WPath + "/canvas.png");
                string path = Server.MapPath("/face2/canvas.png");

                //Salvar a imagem no formato PNG
                bmp.Save(path, ImageFormat.Png);
            }
        }

        return "Imagem foi salva com sucesso";
    }
}
}

My problem is that : As I said it works while I only pass a parameter that is the DATA string. But I also need to pass another string that contains the folder where the image should be saved...

When I put second parameter (Wpath) I started getting the error message below... Can anyone tell me what’s wrong ....??

The following error occurred:

{"Message":"Invalid web service call, Missing value for Parameter: u0027WPath u0027." ,"Stacktrace":" at System.Web.Script.Services.Webservicemethoddata.Callmethod(Object target, Idictionary2 parameters)\r\n at System.Web.Script.Services.WebServiceMethodData.CallMethodFromRawParams(Object target, IDictionary2 Parameters) r n at System.Web.Script.Services.Resthandler.Invokemethod(Httpcontext context, Webservicemethoddata methodData, Idictionary`2 rawParams) r n at System.Web.Script.Services.Resthandler.Executewebservicecall(Httpcontext context, Webservicemethoddata methodData)","Exceptiontype":"System.Invalidoperationexception"}

Answer 1

You’re making a mistake because that’s not how you use the JSON.stringify for what you’re intending.

You passed two parameters to him, here:

JSON.stringify(dados, WPath)

According to the documentation, the second parameter of JSON.stringify is the replacer:

Placer: A Function that alters the behavior of the stringification process, or an array of String and Number Objects that serve as a Whitelist for Selecting/Filtering the properties of the value Object to be included in the JSON string.

In a free translation, the replacer would be "A function that alters the behavior of the string transformation process, or a String and Number array that serve as a list to select and filter the properties of the object to be transformed into string".

I was going to show you how to use the second parameter, but that wasn’t the question, so I’m going to leave a possible solution for your AJAX. Exchange the code I mentioned above for the following:

data: '{"base64":"' + dados + '","WPath":"' + WPath + '"}'

I hope it helps you, any doubt put there in the comments

Answer 2

To whom it may interest the problem was why it was lacking to put the complement of the variable, it was like this :

data: '{"base64":"' + dados + '","fileName":"' + nomearq + '"}',

But that’s what’s right : data: '{"base64":"' + dados.base64 + '","fileName":"' + nomearq + '"}',

Here’s the record for future sufferers. Abs.

Answer 3

Thank you Diego...

I don’t have much experience with AJAX I did what you suggested but is giving a syntax error that I can not identify... follows picture..