Calling JSON web service with parameters - Objective C - iOS

问题

I'm trying to call a simple JSON webservice with a parameter in objective c. Doesn't work so far.

Here is the web service method:

[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public void LogIn(string username, string password)
{
    Context.Response.Write(username + "___" + password);
    Context.Response.End();
}

Here is my Objective C code:

// Build dictionnary with parameters
NSString *username = @"usernameTest";
NSString *password = @"passwordTest";
NSMutableDictionary *dictionnary = [NSMutableDictionary dictionary];
[dictionnary setObject:username forKey:@"username"];
[dictionnary setObject:password forKey:@"password"];

NSError *error = nil;
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dictionnary
                                                   options:kNilOptions
                                                     error:&error];   

NSString *urlString = @"http://localhost:8080/ListrWS.asmx/LogIn";
NSURL *url = [NSURL URLWithString:urlString];

// Prepare the request
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:@"POST"];
[request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
[request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
[request setValue:@"json" forHTTPHeaderField:@"Data-Type"];
[request setValue:[NSString stringWithFormat:@"%d", [jsonData length]]  forHTTPHeaderField:@"Content-Length"];
[request setHTTPBody:jsonData];    

NSError *errorReturned = nil;
NSURLResponse *theResponse =[[NSURLResponse alloc]init];
NSData *data = [NSURLConnection sendSynchronousRequest:request
                                     returningResponse:&theResponse
                                                 error:&errorReturned];
if (errorReturned) 
{
    //...handle the error
}
else 
{
    NSString *retVal = [[NSString alloc] initWithData:data
                                             encoding:NSUTF8StringEncoding];
    NSLog(@"%@", retVal);

}

Here is what:

NSLog(@"%@", retVal);

display:

{"Message":"Thread was being aborted.","StackTrace":"   at System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner)\r\n   

at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)\r\n   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)\r\n
at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)\r\n   at System.Web.Script.Services.WebServiceMethodData.CallMethod(Object target, IDictionary`2 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.Threading.ThreadAbortException"}

Any ideas ?

回答1:

I had a similar problem. I was setting the HTML body with jsonData as you do and it didn't work. It turned out that the JSON service wasn't configured as it was supposed to be.

So, instead of setting the HTML body, try calling the URL like a GET method.

I mean, remove the lines that you set the HTML body, and change the URL to

http://localhost:8080/ListrWS.asmx/LogIn?username=usernameTest&password=passwordTest

Don't change the method (POST).

If this works, you will have to do some work on the server side.

回答2:

For the iOS part,

Your code looks OK. There should be no problem on the client side. But you can do the following debuggings;

• Just before you call sendSynchronousRequest:returningResponse:error insert a breakpoint and check if your jsonData is valid. Because you are not checking the error you assigned for JSON Serialization.
• If there is no problem with your JSON data, find another basic JSON server and try consuming it. If your client-side works, you will know there is something wrong on your server-side.

Cheers

回答3:

in the node <system.web> of web.config add the next lines:

<webServices>
      <protocols>
       <add name="HttpPost"/>
      </protocols>
</webServices>

http://support.microsoft.com/default.aspx?scid=kb;en-us;819267

来源：https://stackoverflow.com/questions/9966614/calling-json-web-service-with-parameters-objective-c-ios