How to make wcf service keep the data between ajax calls?
Suppose that I have simple WCF Service:
[ServiceContract]
public interface ITestService
{
[OperationContract]
[WebInvoke(
Method = "POST",
BodyStyle = WebMessageBodyStyle.Wrapped,
ResponseFormat = WebMessageFormat.Json)]
string GetStatus();
[OperationContract]
[WebInvoke(
Method = "POST",
BodyStyle = WebMessageBodyStyle.Wrapped,
ResponseFormat = WebMessageFormat.Json)]
string SetStatus(string status);
}
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class TestService : ITestService
{
private string _status;
public string GetStatus()
{
return _status;
}
public string SetStatus(string status)
{
_status = status;
return "completed";
}
}
and the Html page that performs two ajax calls to that service:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Wcf services test</title>
<script type="text/javascript" src="Scripts/jquery-1.5.1.min.js"></script>
<script language="javascript" type="text/javascript">
function btnSend_onclick() {
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "Services/TestService.svc/SetStatus",
data:'{"status":"'+jQuery("#txtSetStatus").val()+'"}',
processData: false,
dataType: "json",
//If the call succeeds
success:
function (response) {
jQuery("#lblInfo").text('Service returned: ' + response.SetStatusResult);
},
//If the call fails
error: function (XMLHttpRequest, textStatus, errorThrown) {
jQuery("#lblInfo").text(XMLHttpRequest.responseText);
}
});
}
function btnGetStatus_onclick() {
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "Services/TestService.svc/GetStatus",
processData: false,
dataType: "json",
//If the call succeeds
success:
function (response) {
jQuery("#lblGetStatus").text('Status is: ' + response.GetStatusResult);
},
//If the call fails
error: function (XMLHttpRequest, textStatus, errorThrown) {
jQuery("#lblInfo").text(XMLHttpRequest.responseText);
}
});
}
</script>
</head>
<body>
<input type="text" id="txtSetStatus" />
<button id="btnSend" onclick="return btnSend_onclick()">Send status</button>
<span id="lblStatus"></span>
<span id="lblInfo"></span>
<br />
<button id="btnGetStatus" onclick="return btnGetStatus_onclick()">Get Current Status</button>
<span id="lblGetStatus"></开发者_开发问答span>
</body>
</html>
If I call SetStatus first(by typing something in txtSetStatus input and clicking Send status button), then call GetStatus(by clicking Get Current Status button), then the returned status is null. I understand that this happens because WCF service instance is created each time when a html page performs ajax request. But what is the best practice to keep the data between 2 or more ajax calls?
Well, I've found the answer. It seems that the best way is setting aspNetCompatibilityEnabled=true for my WCF service and then making use of asp.net Session object in order to keep the values temporarily:
public class TestService : ITestService
{
public string GetStatus(string id)
{
var session = System.Web.HttpContext.Current.Session;
var ret= session[id].ToString();
session.Remove(id);
return ret;
}
public string SetStatus(string status)
{
var guid = Guid.NewGuid().ToString("D");
var session = System.Web.HttpContext.Current.Session;
session.Add(guid, status);
return guid;
}
}
加载中,请稍侯......
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