如何实现ProgressDialog而活动请求SoapObject从Web服务？ [英] How to implement a ProgressDialog while Activity requests a SoapObject from a Web Service?

问题描述

我知道ProgressDialog与线程的问题已经被问了很多次，但没有一个解决方案，似乎工作为我的项目。基本上我想做的事情是这样的： 1），当用户点击一个按钮的活动发送身份验证请求到服务器 2），而这是被做了ProgressDialog显示 3）当效应初探来了，我想解散ProgressDialog和返回的对象被读取并通过活动PTED间$ P $

如果我： 1）设置线程与效应初探更新的应用领域，下一个方法（这是线程之外）访问现场时，抛出NPE 2）如果我包括在主题下一种方法，第二种方法抛出一个'了java.lang.RuntimeException：内螺纹无法创建处理程序，并没有叫尺蠖prepare（）

对不起了很长的文字，但我完全在这个失去它...我的code是某事是这样的：

 公共类XXX延伸活动实现OnClickListener {

//（...）
私人SoapObject返回object;
私人字符串响应;

/ **第一次创建活动时调用。 * /
@覆盖
公共无效的onCreate（包savedInstanceState）{
    super.onCreate（savedInstanceState）;
    的setContentView（R.layout.main）;

    //（...）
        authProgressDialog = ProgressDialog.show（XXX.this，，鉴定......，真，假）;
        新主题（新的Runnable（）{
            @覆盖
            公共无效的run（）{
                认证（）; //方法是通过SOAP调用API
                authenticateReal（）; //方法处理响应
            }
        }）。开始（）;

        mHandler =新的处理程序（）{
            公共无效的handleMessage（信息MSG）{
                super.handleMessage（MSG）;
                开关（msg.what）{
                    案例10：
                        authProgressDialog.dismiss（）;
                        打破;
                }
            }
        };
    }
}

公共无效验证（）{
    // API的东西（...）
    AndroidHttpTransport AHT =新AndroidHttpTransport（URL）;
    尝试 {
        aht.call（SOAP_ACTION，的SoapEnvelope）;
        返回object =（SoapObject）soapEnvelope.getResponse（）;
        。响应= returnObject.getProperty（ResponseStatus）的toString（）;
    }
    赶上（例外五）{
        e.printStackTrace（）;
    }
    最后 {
        mHandler.sendEmptyMessage（10）;
    }
}

//方法需要访问返回object和效应初探对象和
//在这其中的NPE的或其他异常抛出
公共无效authenticateReal（）{
//（...）
}
 

解决方案

您更好地使用 的AsyncTask （这是Android的方式）：

  @覆盖
公共无效的onCreate（包savedInstanceState）{
    super.onCreate（savedInstanceState）;
    的setContentView（R.layout.main）;

    新TheTask（）执行（）。
}

私有类TheTask扩展的AsyncTask＆LT;虚空，虚空，虚空＆GT; {

    @覆盖
    在preExecute保护无效（）{
        authProgressDialog = ProgressDialog.show（XXX.this，，鉴定......，真，假）;
    }

    @覆盖
    保护无效doInBackground（虚空...... PARAMS）{
        认证（）; //方法是通过SOAP调用API
        authenticateReal（）; //方法处理响应
        返回null;
    }

    @覆盖
    保护无效onPostExecute（无效的结果）{
        authProgressDialog.dismiss（）;
    }
}
 

顺便说一句......我发现这presentation是非常有用的（它谈论REST的应用程序，但可以采用同样的理念，为不同类型的应用程序）的Developing Android的REST客户端应用程序

I know that ProgressDialog with Threads questions have been asked many times but none of the solutions seem to work for my project. Basically what I want to do is this: 1) when a user clicks a button the Activity sends an auth request to the server 2) while this is being done a ProgressDialog is shown 3) when the reponse comes I want to dismiss the ProgressDialog and the return object to be read and interpreted by the Activity

If I: 1) set the Thread to update the Application field with the reponse, the next method (which is outside of the Thread) throws an NPE when accessing the field 2) if I include the next method in the Thread, the second method throws a 'java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()'

Sorry for a long text, but I am totally losing it over this... My code is sth like this:

public class XXX extends Activity implements OnClickListener {

// (...)
private SoapObject returnObject;
private String response;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // (...)
        authProgressDialog = ProgressDialog.show(XXX.this, "", "Authenticating...", true, false);
        new Thread(new Runnable() {
            @Override
            public void run() {
                authenticate(); // method that calls the API via SOAP
                authenticateReal(); // method that handles the response
            }
        }).start();

        mHandler = new Handler() {
            public void handleMessage(Message msg) {
                super.handleMessage(msg);
                switch (msg.what) {
                    case 10:
                        authProgressDialog.dismiss();
                        break;
                }
            }
        };
    }
}

public void authenticate() {
    // API stuff (...)
    AndroidHttpTransport aht = new AndroidHttpTransport(URL);
    try {
        aht.call(SOAP_ACTION, soapEnvelope);
        returnObject = (SoapObject) soapEnvelope.getResponse();
        response = returnObject.getProperty("ResponseStatus").toString();
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    finally {
        mHandler.sendEmptyMessage(10);
    }
}

// Method that needs to access returnObject and reponse objects and
// it is here where the NPE's or other exceptions are thrown
public void authenticateReal() {
// (...)
}

解决方案

You better use AsyncTask (which is the Android way):

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    new TheTask().execute();
}

private class TheTask extends AsyncTask<Void, Void, Void>{

    @Override
    protected void onPreExecute() {
        authProgressDialog = ProgressDialog.show(XXX.this, "", "Authenticating...", true, false);
    }

    @Override
    protected Void doInBackground(Void... params) {
        authenticate(); // method that calls the API via SOAP
        authenticateReal(); // method that handles the response
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        authProgressDialog.dismiss();
    }
}

By the way... I have found this presentation to be very useful (it talks about REST apps, but you can apply the same concept for different kind of apps): Developing Android REST client applications

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