标签: android-asynctask

我正在尝试使用水平进度条,Asynctask但它不适合我.它不显示进度百分比.

在这里我把我的xml和活动文件和屏幕截图文件.

布局xml

<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android" 
        android:id="@+id/progresslayout"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        >

        <ImageView
            android:id="@+id/imagepeakmedia"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:adjustViewBounds="true"
            android:layout_alignParentTop="true"
            android:layout_centerHorizontal="true"
            android:layout_centerVertical="true"
            android:src="@drawable/peakmedialogo" 
            android:layout_marginTop="100sp"
             />



        <TextView
            android:id="@+id/text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/imagepeakmedia"
            android:layout_centerHorizontal="true"
            android:textSize="25sp"
           android:text="" />

        <TextView
            android:id="@+id/textpercentage"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/imagepeakmedia"
            android:layout_toRightOf="@+id/text"
            android:layout_centerHorizontal="true"
            android:textSize="25sp"
            android:layout_marginLeft="5sp"
            android:text="%" />

        <ProgressBar
            android:id="@+id/progressBar"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_below="@+id/text"
            style="?android:attr/progressBarStyleHorizontal"

             />

    </RelativeLayout>

TestActivity.java

public class TestActivity extends Activity {


    ProgressDialog progressdialog;

    RelativeLayout progresslayout;
    ProgressBar progressbar;
    TextView textprogressbar;
    TextView textpercentage;
    TextView textdownload;

    boolean progress=true;
    /** Called when the activity is first created. */ …

我正在使用Caldroid Lib在我的Android App中创建一个自定义日历,我需要从我的Web服务器加载数据,我有一个asynctask填充HashMap然后我把这些数据放在这样的arraylist中:

class Asistencia extends AsyncTask<Void, Void, Void> {
        @Override
        protected Void doInBackground(Void... params) {

            arraylist = new ArrayList<HashMap<String, String>>();
            // Retrieve JSON Objects from the given URL address
            jsonobject = JSONfunctions
                    .getJSONfromURL("http://www.gettford.net/comunidad/api/calendario.php?usuarioID="
                            + usuarioID);
            if (jsonobject != null && jsonobject.length() > 0) {
                try {
                    // Locate the array name in JSON
                    jsonarray = jsonobject.getJSONArray("datos");

                    for (int i = 0; i < jsonarray.length(); i++) {
                        HashMap<String, String> map = new HashMap<String, String>();
                        jsonobject = jsonarray.getJSONObject(i);
                        // Retrive JSON …

我已经创建了一个应用程序,其中用户登录他的帐户.为此我使用asyncTask.Everything工作正常,但事情是当我得到响应,我希望进度条停止.但它继续下去.

异步任务

protected void onPreExecute() {
        super.onPreExecute ();
        CommonFunctions.showProgress (c, "Please Wait", true);
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute (s);
        try {
            JSONObject jsonObject = new JSONObject (s.trim ());
            JSONObject NewDataSet = jsonObject.getJSONObject ("NewDataSet");
            JSONObject Table = NewDataSet.getJSONObject ("Table");
            String User_ID = Table.getString ("User_ID");
            String Vendor_IEntity_Code = Table.getString ("Vendor_IEntity_Code");
            String Vendor_Name = Table.getString ("Vendor_Name");


            // setting the preferences
            SettingPreference.setUserId (c, User_ID);
            SettingPreference.setVendorId (c, Vendor_IEntity_Code);
            SettingPreference.setVendorName (c, Vendor_Name);

        } catch (JSONException e) {
            e.printStackTrace ();
        }
        CommonFunctions.showProgress (c, "", …

我有一个启动屏幕,运行asyncTask从API下载数据.在那个任务上OnPostExecute我运行下一个asyncTask发送存储的电子邮件.一旦完成,我需要AlertDialog弹出一个ok按钮,以便用户知道下载完成.我用这个问题得到了尽可能的:

AsyncTask里面的Android AlertDialog

现在,当我尝试向对话框添加属性时,我收到NullPointerException:

public class JSONParser extends AsyncTask<String, String, JSONObject> {
     Context c;

     public JSONParser(int api,Context c) {
          this.api= api;
          this.c = c;
     }
     ...
     protected void onPostExecute(JSONObject result) {
          JSONObject output = new JSONEmailParser(c).executeOnExecutor(AsyncTask.SERIAL_EXECUTOR, new String[] {null,null,null,null}).get();
     }
}

public class JSONEmailParser extends AsyncTask<String, String, JSONObject> {
     Context c;

     AlertDialog.Builder builder;

     public JSONEmailParser(Context c){
          this.c = c;
     }

     protected void onPreExecute(int api){
          builder = new AlertDialog.Builder(SplashScreen.this);
     }

     ...

     protected void …

我正在尝试使用AsyncTask捕获httpclient的响应，但抛出以下错误，验证字符串中的doInBackground是否不兼容：

“返回类型与AsyncTask不兼容”

我尝试捕获httpclient的响应字符串，并在doInBackground中返回它，以便在onPostExecute中使用它。

有人可以帮助我。

谢谢

private String insertar(){  
            String response = "";
            HttpClient httpclient;
            List<NameValuePair> nameValuePairs;
            HttpPost httppost;
            httpclient=new DefaultHttpClient();
            httppost= new HttpPost("http://10.1.1.20/pruebaAndroid/insert.php"); // Url del Servidor      
            //Añadimos nuestros datos
            nameValuePairs = new ArrayList<NameValuePair>(4);
            nameValuePairs.add(new BasicNameValuePair("dni",dni.getText().toString().trim()));
            nameValuePairs.add(new BasicNameValuePair("nombre",nombre.getText().toString().trim()));
            nameValuePairs.add(new BasicNameValuePair("telefono",telefono.getText().toString().trim()));
            nameValuePairs.add(new BasicNameValuePair("email",email.getText().toString().trim()));

            try {
               httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));// envio las variables

               // capturo lo que devuelve, si no devolviera nada solo hago la ejecucion del httpclient sin el handler

               ResponseHandler<String> responseHandler = new BasicResponseHandler(); 
               response = httpclient.execute(httppost, responseHandler);

               //----------------------------------------------------------------

            } catch (UnsupportedEncodingException …

我创建了这个AsyncTask内部类,现在我想把它变成外层.这是代码:

    private class DownloadDataFromServer extends AsyncTask<String, Integer, String> {
        ProgressDialog dialog;
        boolean connErr = false;
        boolean soErr = false;

        @Override
        protected void onPreExecute() {
            dialog = new ProgressDialog(HomePage.this); !!!!PROBLEM!!!!
            dialog.setIndeterminate(false);
            dialog.setMax(100);
            dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            dialog.setCancelable(false);
            dialog.setTitle("Download");
            dialog.setMessage("Updating...");
            dialog.show();

            super.onPreExecute();
        }

        @Override
        protected String doInBackground(String... urls) {
            // do something
        }

        protected void onProgressUpdate(Integer... progress) {
            // Update the progress
            dialog.setProgress(progress[0]);
        }

        @Override
        protected void onPostExecute(String result) {
            if (connErr || soErr) {
                String msg = "Bad connection";
                AlertDialog.Builder builder;
                builder = new …

我编写了一个类,它启动一个http连接来获取例如网站的文本.我使用AsyncTask但我得到了NetworkOnMainException.你能救我吗？班级

public class getXMLData extends AsyncTask<String, Void, String> {
TextView _textview;

public getXMLData(TextView textview) {
    _textview = textview;
}

protected String doInBackground(String... url)
{
    String _text = "";
    try {
        try {
            URL _url = new URL(url[0]);
            HttpURLConnection con = (HttpURLConnection) _url.openConnection();
            _text = readStream(con.getInputStream());
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    return _text;
}

protected void onPostExecute(String result)
{
    _textview.setText(result.toCharArray(), 0, result.length());
}


private String readStream(java.io.InputStream in) {
    java.io.BufferedReader reader = null; …

我正在使用毕加索来加载图像作为我的活动的背景,我想使用AsyncTask,而图像正在加载,完成后进度条会解散,以便为我的应用程序提供更好的外观,

这是我的代码:

  private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mProgressDialog = new ProgressDialog(MainActivity.this);
        mProgressDialog.setMessage("Chargement...");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.show();

    }

    @Override
    protected Void doInBackground(Void... params) {
           Picasso.with(MainActivity.this).load("http://tv2.orangeadd.com/mediacenter-data/ofc__bg_home.jpg").into(background,new com.squareup.picasso.Callback() {
                 @Override
                 public void onSuccess() {
               mProgressDialog.dismiss();
                 }

                 @Override
                 public void onError() {

                 }
             }); 
        return null;
    }
    @Override
    protected void onPostExecute(Void result) {





    }
    }

这总是显示错误并强制我的应用程序退出!

多谢你们 :)

我有一个异步任务,最终创建参数电子邮件,关于.异步任务位于onCreate方法中,此CustomListAdapter也是如此.我想在asyncTask中的onCreate中移动CustomListAdapter.onPostExecute我的问题是这this意味着应用程序的上下文.当我移动它时,onPostExecute它不再具有上下文.我试图用它替换它getApplicationContext(),activityName.this.getApplicationContext但它不起作用,因为它期望应用程序的上下文.我发现这种静态方式可以在Android上获得"上下文"？但由于某种原因,我无法在清单中定义名称.我可以在asyncTask的onPostExecute方法中使用哪种获取应用程序上下文的方法？或者我应该以上下文作为参数来制作Asynck任务？

CustomListAdapter adapter=new CustomListAdapter(this, email,about);
                list=(ListView)findViewById(R.id.list);


 list.setAdapter(adapter);

            list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                                        int position, long id) {
                    // TODO Auto-generated method stub
                    String Slecteditem= email.get(position);
                    Toast.makeText(getApplicationContext(), Slecteditem, Toast.LENGTH_SHORT).show();

                }
            });

我想用rxAndroid重写项目.在我的代码中,我有这个简单的部分:

public void chkLogin(String login, String password) {
    String[] myTaskParams = { login, password };
    new ChkLoginTask().execute(myTaskParams);
}

private class ChkLoginTask extends AsyncTask<String, Void, LoginStatus> {
    @Override
    protected void onPreExecute(){
        view.showLoadingSpinner();
    }

    @Override
    protected LoginStatus doInBackground(String... params) {
        return app.getAPI().checkLogin(params[0], params[1]);
    }

    @Override
    protected void onPostExecute(LoginStatus result) {
        view.hideLoadingSpinner();
        if(result == null)
            view.onConnectionError();
        else{
            view.onChkLoginSuccess(result);
        }
    }
}

在这段代码中,我只用两个参数在AsyncTask中调用我的api方法,然后根据它的结果做出反应.

现在我想用rxAndroid编写这段代码,但我坚持下去......我知道rx如何处理对UI元素的反应,但无法找到有关它如何与参数化AsyncTask一起工作的信息

在这种情况下使用RX是否正确？