加载网络时显示对话框 [英] Display Dialog when loading internet

问题描述

我试图加载的Htt prequest时创建一个对话框。但它在我点击从去年到活动中意图加载，但不是这个活动的开始。

和对话只是0.00001sec所示，然后解雇。

难道我错实现它？

下面是我的codeS

  @覆盖
公共无效的onCreate（捆绑savedInstanceState）{
    super.onCreate（savedInstanceState）;
    的setContentView（R.layout.activity_main）;
    HttpPostHandler2处理程序=新HttpPostHandler2（）;
    字符串的URL =HTTP：// XXXXXX;
    handler.execute（URL）;
}公共类HttpPostHandler2扩展的AsyncTask＆LT;弦乐，太虚，字符串＆GT; {    私人字符串resultJSONString = NULL;
    私人ProgressDialog pDialog;    公共字符串getResultJSONString（）{
        返回resultJSONString;
    }    公共无效setResultJSONString（字符串resultJSONString）{
        this.resultJSONString = resultJSONString;
    }    @覆盖
    在preExecute保护无效（）{
        super.on preExecute（）;
            pDialog =新ProgressDialog（MainActivity.this）;
            pDialog.setMessage（请等待）;
            pDialog.setIndeterminate（假）;
            pDialog.setCancelable（假）;
            pDialog.show（）;
    }    @覆盖
    保护字符串doInBackground（字符串... PARAMS）{        CredentialsProvider credProvider =新BasicCredentialsProvider（）;
        credProvider.setCredentials（新AuthScope（AuthScope.ANY_HOST，
                AuthScope.ANY_PORT），新UsernamePasswordCredentials（核心，
                core1234））;
        串responseContent =;        HttpClient的HttpClient的=新DefaultHttpClient（）;
        （（AbstractHttpClient）的HttpClient）.setCredentialsProvider（credProvider）;
        HttpPost httpPost =新HttpPost（PARAMS [0]）;        HTT presponse响应= NULL;
        尝试{
            //执行HTTP POST请求
            响应= httpClient.execute（httpPost）;
            responseContent = EntityUtils.toString（response.getEntity（））;
        }赶上（ClientProtocolException E）{
            // TODO自动生成catch块
        }赶上（IOException异常五）{
            // TODO自动生成catch块
        }
        setResultJSONString（responseContent）;
        //返回新的JSONObject（responseContent）;
        返回responseContent;
    }    @覆盖
    保护无效onPostExecute（字符串结果）{
        pDialog.dismiss（）;
        super.onPostExecute（结果）;
        resultJSONString =结果;
    }
}
 

解决方案

确保的 HttpPostHandler2 足够长，以显示工作 pDialog 。如果不是，它真的会很快消失。
但是，你不能在的onCreate 显示GUI。要显示的对话框中，你应该将它们移动到在onStart ：

  @覆盖
公共无效的onCreate（捆绑savedInstanceState）{// GUI没有准备好：没有显示
  super.onCreate（savedInstanceState）;
  的setContentView（R.layout.activity_main）;
  HttpPostHandler2处理程序=新HttpPostHandler2（）;}@覆盖
保护无效调用onStart（）{// GUI已准备就绪
   字符串的URL =HTTP：// XXXXXX;
   handler.execute（URL）;
}
 

有关更多信息，请参见注释。

I am trying to create a dialog when loading Httprequest. But it load during the i click to intent from last Activity, but not the start of this Activity.

And the dialog just shown in 0.00001sec then dismiss.

Am i implement it wrongly?

Here is my codes

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    HttpPostHandler2 handler = new HttpPostHandler2();
    String URL ="http://xxxxxx";        
    handler.execute(URL);
}

public class HttpPostHandler2 extends AsyncTask<String, Void, String> {

    private String resultJSONString = null;
    private ProgressDialog pDialog;

    public String getResultJSONString() {
        return resultJSONString;
    }

    public void setResultJSONString(String resultJSONString) {
        this.resultJSONString = resultJSONString;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
            pDialog = new ProgressDialog(MainActivity.this);
            pDialog.setMessage("Please Wait");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
    }

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

        CredentialsProvider credProvider = new BasicCredentialsProvider();
        credProvider.setCredentials(new AuthScope(AuthScope.ANY_HOST,
                AuthScope.ANY_PORT), new UsernamePasswordCredentials("core",
                "core1234"));
        String responseContent = "";

        HttpClient httpClient = new DefaultHttpClient();
        ((AbstractHttpClient) httpClient).setCredentialsProvider(credProvider);
        HttpPost httpPost = new HttpPost(params[0]);

        HttpResponse response = null;
        try {
            // Execute HTTP Post Request
            response = httpClient.execute(httpPost);
            responseContent = EntityUtils.toString(response.getEntity());
        } catch (ClientProtocolException e) {
            // TODO Auto-generated catch block
        } catch (IOException e) {
            // TODO Auto-generated catch block
        }
        setResultJSONString(responseContent);
        // return new JSONObject(responseContent);
        return responseContent;
    }

    @Override
    protected void onPostExecute(String result) {
        pDialog.dismiss();  
        super.onPostExecute(result);
        resultJSONString = result;
    }
}

解决方案

Make sure that the work of HttpPostHandler2 is long enough to display the pDialog. If it not, it will disappear really soon. However, you cannot display GUI in onCreate. To display the dialog, you should move them to onStart:

@Override
public void onCreate(Bundle savedInstanceState) {//GUI not ready: nothing is shown
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  HttpPostHandler2 handler = new HttpPostHandler2();

}

@Override
protected void onStart () {//GUI is ready
   String URL ="http://xxxxxx";
   handler.execute(URL);
}

See comment for more information.

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