Android应用程序中的Web服务调用错误

Question

我试图从我的Android应用程序调用Web服务，但是我收到了这个错误： SoapFault - faultcode：＆＃39; soap：Client＆＃39; faultstring：＆＃39;服务器无法识别HTTP标头SOAPAction的值：http://tempuri.org/CelsiusToFahrenheit。＆＃39; faultactor：＆＃39; null＆＃39;详情：org.kxml2.kdom.Node@41b9f3a0

我的代码如下：

package com.example.test;

import org.ksoap2.SoapEnvelope;
import org.ksoap2.serialization.PropertyInfo;
import org.ksoap2.serialization.SoapObject;
import org.ksoap2.serialization.SoapPrimitive;
import org.ksoap2.serialization.SoapSerializationEnvelope;
import org.ksoap2.transport.HttpTransportSE;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

private final String NAMESPACE = "http://tempuri.org/";
private final String URL =           
"http://www.w3schools.com/webservices/tempconvert.asmx";
private final String SOAP_ACTION = 
"http://tempuri.org/CelsiusToFahrenheit";
private final String METHOD_NAME = "CelsiusToFahrenheit";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    TextView tv = new TextView(this);        
    tv.setText("Hello, Android"); 
    setContentView(R.layout.activity_main);

       Button btn = (Button)findViewById(R.id.button1);       
       btn.setOnClickListener(new OnClickListener(){  

          @Override
          public void onClick(View v) 
          {   
                new LongRunningAsyncTask().execute("");
          }       
        }
       );           
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is 
present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

class LongRunningAsyncTask extends AsyncTask<String, String, String> {

    String currentText;

      @Override
       protected String doInBackground(String... params) {          

        currentText = getFahrenheit("10");
        return null;
       }

      @Override
       protected void onPreExecute() {
          currentText = "Start: ";
         super.onPreExecute();
       }

      @Override
       protected void onPostExecute(String result) {
          TextView tv = (TextView)findViewById(R.id.textView1);
          tv.setText("End: " + currentText);
         super.onPostExecute(result);
       }
    }   

public String getFahrenheit(String celsius) {
    //Create request
    SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
    //Property which holds input parameters
    PropertyInfo celsiusPI = new PropertyInfo();
    //Set Name
    celsiusPI.setName("Celsius");
    //Set Value
    celsiusPI.setValue(celsius);
    //Set dataType
    celsiusPI.setType(double.class);
    //Add the property to request object
    request.addProperty(celsiusPI);
    //Create envelope
    SoapSerializationEnvelope envelope = new 
SoapSerializationEnvelope(SoapEnvelope.VER11);
    envelope.dotNet = true;
    //Set output SOAP object
    envelope.setOutputSoapObject(request);
    //Create HTTP call object
    HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
    androidHttpTransport.debug = true;

    try {
        //Invole web service
        androidHttpTransport.call(SOAP_ACTION, envelope);
        //Get the response
        SoapPrimitive response = (SoapPrimitive) envelope.getResponse();
        //Assign it to fahren static variable
        return response.toString();

    } catch (Exception e) {
        e.printStackTrace();
        String error = e.getMessage();
        return error;
    }
}   
}

错误在这一行： SoapPrimitive response =（SoapPrimitive）envelope.getResponse（）;

我认为调用函数无法正常运行，但调试器在获取响应时会出错：envelope.getResponse