糊涂把code中的AsyncTask [英] confused to put code in AsyncTask
本文介绍了糊涂把code中的AsyncTask的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有这个code接收聊天消息。但我弄糊涂了，当我试图把它放在的AsyncTask 。我已经警告读不能得到解决为 read.readline（）当我把它放在 postexecute 。
我想在此背景下code的工作，检查存在的任何消息来不来。我想问问，使code一直在后台运行，它是使用的AsyncTask 或有任何其他方式做到这一点？
请人帮我，我困惑如何做到这一点。谢谢
收到消息部分
HttpURLConnection的连接;
网址URL = NULL;
尝试{
linkurl =新Koneksi（本）;
SERVER_URL = linkurl.getUrl（）;
SERVER_URL + =/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
URL =新的URL（SERVER_URL）;
连接=（HttpURLConnection类）url.openConnection（）;
connection.setDoOutput（真正的）;
connection.setRequestProperty（内容类型，应用程序/ x-WWW的形式urlen codeD）;
connection.setRequestMethod（POST）;
HttpClient的HttpClient的=新DefaultHttpClient（）;
HttpPost httpPost =新HttpPost（SERVER_URL）;
// ArrayList的＆LT;的NameValuePair＆GT;参数=新的ArrayList＆LT;的NameValuePair＆GT;（）;
//添加参数
//httpPost.setEntity(new UrlEn codedFormEntity（参数））;
HTT presponse HTT prespose = httpClient.execute（httpPost）;
HttpEntity httpEntity = HTT prespose.getEntity（）;
//读取内容
InputStream的时间= httpEntity.getContent（）;
的BufferedReader读=新的BufferedReader（新的InputStreamReader（在））;
弦乐味精=TES;
而（真）
{
尝试 {
味精= read.readLine（）;
Log.d（，MSGGG：+ MSG）;
//msgList.add(msg）;
}赶上（IOException异常E）{
// TODO自动生成的catch块
e.getMessage（）;
}
如果（MSG == NULL）
{
打破;
}
其他
{
showMessage（味精，假）;
}
}}
赶上（IOException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
}
}
AsyncTask的一部分，我试图 - 更新，但得到的 getintent警告（）在这里我必须把这些codeS
公共类ReceivedTask扩展的AsyncTask＆LT;字符串，字符串，字符串＆GT; {
束束= this.getIntent（）getExtras（）。
最后的字符串参数2 = bundle.getString（keyUserId）;
最后的字符串参数3 = bundle.getString（keyChatsId）;
串param4 = bundle.getString（keyMessagesId）;
@覆盖
在preExecute保护无效（）{
// TODO自动生成方法存根
super.on preExecute（）;
}
@覆盖
保护字符串doInBackground（字符串...为arg0）{
// TODO自动生成方法存根
HttpURLConnection的连接;
网址URL = NULL;
尝试{
linkurl =新Koneksi（ChatRoom.this）;
SERVER_URL = linkurl.getUrl（）;
SERVER_URL + =/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
URL =新的URL（SERVER_URL）;
连接=（HttpURLConnection类）url.openConnection（）;
connection.setDoOutput（真正的）;
connection.setRequestProperty（内容类型，应用程序/ x-WWW的形式urlen codeD）;
connection.setRequestMethod（POST）;
HttpClient的HttpClient的=新DefaultHttpClient（）;
HttpPost httpPost =新HttpPost（SERVER_URL）;
// ArrayList的＆LT;的NameValuePair＆GT;参数=新的ArrayList＆LT;的NameValuePair＆GT;（）;
//添加参数
//httpPost.setEntity(new UrlEn codedFormEntity（参数））;
HTT presponse HTT prespose = httpClient.execute（httpPost）;
HttpEntity httpEntity = HTT prespose.getEntity（）;
//读取内容
InputStream的时间= httpEntity.getContent（）;
的BufferedReader读=新的BufferedReader（新的InputStreamReader（在））;
弦乐味精=TES;
而（真）
{
尝试 {
味精= read.readLine（）;
Log.d（，MSGGG：+ MSG）;
//msgList.add(msg）;
}赶上（IOException异常E）{
// TODO自动生成的catch块
e.getMessage（）;
}
如果（MSG == NULL）
{
打破;
}
其他
{
showMessage（味精，假）;
}
}}
赶上（IOException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
}
}
}
ChatRoom.java - 我完全code
公共类聊天室延伸活动{
公共Koneksi linkurl;
字符串SERVER_URL;
私人的EditText的MessageText;
私人TextView的meLabel;
私人TextView的friendLabel;
私人的ViewGroup messagesContainer;
私人滚动型scrollContainer;
/ *私人处理程序处理程序=新的处理程序（）; * /
@覆盖
保护无效的onCreate（包savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.chatpage）;
messagesContainer =（ViewGroup中）findViewById（R.id.messagesContainer）;
scrollContainer =（滚动型）findViewById（R.id.scrollContainer）;
按钮sendMessageButton =（按钮）findViewById（R.id.sendButton）;
束束= this.getIntent（）getExtras（）。
/ *最后弦乐paramnama = bundle.getString（非农产品市场准入）; * /
=的MessageText（的EditText）findViewById（R.id.messageEdit）;
meLabel =（TextView中）findViewById（R.id.meLabel）;
friendLabel =（TextView中）findViewById（R.id.friendLabel）;
meLabel.setText（我）;
最后的字符串参数1 = bundle.getString（keyCourseId）;
最后的字符串参数2 = bundle.getString（keyUserId）;
最后的字符串参数3 = bundle.getString（keyChatsId）;
串param4 = bundle.getString（keyMessagesId）;
sendMessageButton.setOnClickListener（新View.OnClickListener（）{
@覆盖
公共无效的onClick（视图v）{
// TODO自动生成方法存根
ArrayList的＆LT;的NameValuePair＆GT; postParameters =新的ArrayList＆LT;的NameValuePair＆GT;（）;
postParameters.add（新BasicNameValuePair（信息，messageText.getText（）的toString（）））;
串响应=无效;
尝试 {
linkurl =新Koneksi（ChatRoom.this）;
SERVER_URL = linkurl.getUrl（）;
SERVER_URL + =/mobile/ChatKirimTeks.php?idu="+param2+"&idch="+param3;
响应= CourseHttpClient.executeHttpPost（SERVER_URL，postParameters）;
字符串解析度= response.toString（）;
RES = res.trim（）;
RES = res.replaceAll（\\ S +，）;
如果（res.equals（1））{
。字符串messageString = messageText.getText（）的toString（）;
showMessage（messageString，真正的）;
messageText.getText（）清（）。
}其他
{
CreateDialog函数（MAAF，消息安达Gagal Terkirim）;
}
}
赶上（例外五）{
messageText.setText（e.toString（））;
}
}
}）;
HttpURLConnection的连接;
网址URL = NULL;
尝试{
linkurl =新Koneksi（本）;
SERVER_URL = linkurl.getUrl（）;
SERVER_URL + =/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
URL =新的URL（SERVER_URL）;
连接=（HttpURLConnection类）url.openConnection（）;
connection.setDoOutput（真正的）;
connection.setRequestProperty（内容类型，应用程序/ x-WWW的形式urlen codeD）;
connection.setRequestMethod（POST）;
HttpClient的HttpClient的=新DefaultHttpClient（）;
HttpPost httpPost =新HttpPost（SERVER_URL）;
// ArrayList的＆LT;的NameValuePair＆GT;参数=新的ArrayList＆LT;的NameValuePair＆GT;（）;
//添加参数
//httpPost.setEntity(new UrlEn codedFormEntity（参数））;
HTT presponse HTT prespose = httpClient.execute（httpPost）;
HttpEntity httpEntity = HTT prespose.getEntity（）;
//读取内容
InputStream的时间= httpEntity.getContent（）;
的BufferedReader读=新的BufferedReader（新的InputStreamReader（在））;
弦乐味精=TES;
而（真）
{
尝试 {
味精= read.readLine（）;
Log.d（，MSGGG：+ MSG）;
//msgList.add(msg）;
}赶上（IOException异常E）{
// TODO自动生成的catch块
e.getMessage（）;
}
如果（MSG == NULL）
{
打破;
}
其他
{
showMessage（味精，假）;
}
}}
赶上（IOException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
}
}
公共类ReceivedTask扩展的AsyncTask＆LT;字符串，字符串，字符串＆GT; {
@覆盖
在preExecute保护无效（）{
}
@覆盖
保护字符串doInBackground（字符串...为arg0）{
// TODO自动生成方法存根
HttpURLConnection的连接;
网址URL = NULL;
尝试{
linkurl =新Koneksi（ChatRoom.this）;
SERVER_URL = linkurl.getUrl（）;
SERVER_URL + =/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
URL =新的URL（SERVER_URL）;
连接=（HttpURLConnection类）url.openConnection（）;
connection.setDoOutput（真正的）;
connection.setRequestProperty（内容类型，应用程序/ x-WWW的形式urlen codeD）;
connection.setRequestMethod（POST）;
HttpClient的HttpClient的=新DefaultHttpClient（）;
HttpPost httpPost =新HttpPost（SERVER_URL）;
// ArrayList的＆LT;的NameValuePair＆GT;参数=新的ArrayList＆LT;的NameValuePair＆GT;（）;
//添加参数
//httpPost.setEntity(new UrlEn codedFormEntity（参数））;
HTT presponse HTT prespose = httpClient.execute（httpPost）;
HttpEntity httpEntity = HTT prespose.getEntity（）;
//读取内容
InputStream的时间= httpEntity.getContent（）;
的BufferedReader读=新的BufferedReader（新的InputStreamReader（在））;
}
赶上（IOException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
返回null;
}
}
@覆盖
保护无效onPostExecute（字符串结果）{
// TODO自动生成方法存根
super.onPostExecute（结果）;
弦乐味精=TES;
而（真）
{
尝试 {
味精= read.readLine（）;
Log.d（，MSGGG：+ MSG）;
//msgList.add(msg）;
}赶上（IOException异常E）{
// TODO自动生成的catch块
e.getMessage（）;
}
如果（MSG == NULL）
{
打破;
}
其他
{
showMessage（味精，假）;
}
}
}
}
公共无效showMessage（字符串消息，布尔leftSide）{
最后的TextView TextView的=新的TextView（ChatRoom.this）;
textView.setTextColor（Color.BLACK）;
textView.setText（消息）;
INT bgRes = R.drawable.left_message_bg;
LinearLayout.LayoutParams PARAMS =新LinearLayout.LayoutParams（
LinearLayout.LayoutParams.WRAP_CONTENT，LinearLayout.LayoutParams.WRAP_CONTENT）;
如果（！leftSide）{
bgRes = R.drawable.right_message_bg;
params.gravity = Gravity.RIGHT;
}
textView.setLayoutParams（PARAMS）;
textView.setBackgroundResource（bgRes）;
runOnUiThread（新的Runnable（）{
@覆盖
公共无效的run（）{
messagesContainer.addView（TextView的）;
//滚动到底
如果（scrollContainer.getChildAt（0）！= NULL）{
scrollContainer.scrollTo（scrollContainer.getScrollX（），scrollContainer.getChildAt（0）.getHeight（））;
}
scrollContainer.fullScroll（View.FOCUS_DOWN）;
}
}）;
}
私人无效CreateDialog函数（字符串标题，文本字符串）{
AlertDialog广告=新AlertDialog.Builder（本）
.setPositiveButton（OK，NULL）
.setTitle（标题）
.setMessage（文本）
。创建（）;
ad.show（）;
}
}
解决方案
你得到错误信息读不能得到解决由于Android禁止用户从访问互联网用户界面线程。你所要做的是在后台线程。事实上，使用点的AsyncTask 是保持用户界面线程尽可能免费。
每当我用的AsyncTask ，我通常会创建一个类来保存任务的所有参数，另一个类来保存结果。另外，我要确保结果类可以重新present可能出现的任何错误情况，如：抛出异常。所以，我使用的通用模板看起来是这样的（注：这是当不需要进度报告）。
公共类MyActivity延伸活动{
静态类MyAsyncTaskParameters {
//把所有任务将在这里需要的参数
}
无效KickOffAsynctask（...）{//各种参数所要求的在手任务
MyAsyncTaskParameters PARAMS =新MyAsyncTaskParameters（...）; //封装了所有的参数
MyAsyncTask newtask =新MyAsyncTask（）;
newtask.execute（PARAMS）;
}
静态类MyAsyncTaskResults {
//把所有的结果，该任务可以在这里产生
//注意：可能会出现错误的任务，也异常
//可以扔掉的任务，所以有可能
//这个类来描述所有错误情况可能发生
}
静态类MyAsyncTask扩展的AsyncTask＆LT; MyAsyncTaskParameters，太虚，MyAsyncTaskResults＆GT; {
@覆盖
保护MyAsyncTaskResults doInBackground（MyAsyncTaskParameters ... PARAMS）{
MyAsyncTaskResults结果=新MyAsyncTaskResults（）;
尝试 {
MyAsyncTaskParameters taskParameters = PARAMS [0];
//此方法在后台线程中运行，因此
//做尽可能多的在这里的AsyncTask的。
}赶上（的Throwable E）{
//结果集对象，以表明发生了异常。
}
返回结果;
}
@覆盖
保护无效onPostExecute（MyAsyncTaskResults RES）{
//这个方法将在用户界面线程中运行。
//用它来处理与存储在水库的结果。
//如果发生错误，则资源对象将有它存储
//所以采取适当的行动，例如报告给用户。
}
}
}
I have this code to receive chat messages. but i got confused when i tried to place it in AsyncTask. i have warning read cannot be resolved for read.readline() when i put it in postexecute .
i want to make this code work in background, to check there is any messages coming or not. and i wanna ask, to make the code always running in background is it use AsyncTask or there is any other way to do it?
anyone please help me, i confused how to make it. thank you
receive message part
HttpURLConnection connection;
URL url = null;
try{
linkurl = new Koneksi(this);
SERVER_URL = linkurl.getUrl();
SERVER_URL += "/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
url = new URL(SERVER_URL);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestMethod("POST");
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(SERVER_URL);
//ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
//add parameter
//httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpRespose = httpClient.execute(httpPost);
HttpEntity httpEntity = httpRespose.getEntity();
//read content
InputStream in = httpEntity.getContent();
BufferedReader read = new BufferedReader(new InputStreamReader(in));
String msg = "tes";
while(true)
{
try {
msg = read.readLine();
Log.d("","MSGGG: "+ msg);
//msgList.add(msg);
} catch (IOException e) {
// TODO Auto-generated catch block
e.getMessage();
}
if(msg == null)
{
break;
}
else
{
showMessage(msg, false);
}
}}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
AsyncTask part that i tried - updated but get warning at getintent() where i must put these codes?
public class ReceivedTask extends AsyncTask<String, String, String> {
Bundle bundle = this.getIntent().getExtras();
final String param2 = bundle.getString("keyUserId");
final String param3 = bundle.getString("keyChatsId");
String param4 = bundle.getString("keyMessagesId");
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
HttpURLConnection connection;
URL url = null;
try{
linkurl = new Koneksi(ChatRoom.this);
SERVER_URL = linkurl.getUrl();
SERVER_URL += "/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
url = new URL(SERVER_URL);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestMethod("POST");
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(SERVER_URL);
//ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
//add parameter
//httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpRespose = httpClient.execute(httpPost);
HttpEntity httpEntity = httpRespose.getEntity();
//read content
InputStream in = httpEntity.getContent();
BufferedReader read = new BufferedReader(new InputStreamReader(in));
String msg = "tes";
while(true)
{
try {
msg = read.readLine();
Log.d("","MSGGG: "+ msg);
//msgList.add(msg);
} catch (IOException e) {
// TODO Auto-generated catch block
e.getMessage();
}
if(msg == null)
{
break;
}
else
{
showMessage(msg, false);
}
}}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
ChatRoom.java - my full code
public class ChatRoom extends Activity {
public Koneksi linkurl;
String SERVER_URL;
private EditText messageText;
private TextView meLabel;
private TextView friendLabel;
private ViewGroup messagesContainer;
private ScrollView scrollContainer;
/* private Handler handler = new Handler();*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.chatpage);
messagesContainer = (ViewGroup) findViewById(R.id.messagesContainer);
scrollContainer = (ScrollView) findViewById(R.id.scrollContainer);
Button sendMessageButton = (Button) findViewById(R.id.sendButton);
Bundle bundle = this.getIntent().getExtras();
/*final String paramnama = bundle.getString("nama");*/
messageText = (EditText) findViewById(R.id.messageEdit);
meLabel = (TextView) findViewById(R.id.meLabel);
friendLabel = (TextView) findViewById(R.id.friendLabel);
meLabel.setText("me");
final String param1 = bundle.getString("keyCourseId");
final String param2 = bundle.getString("keyUserId");
final String param3 = bundle.getString("keyChatsId");
String param4 = bundle.getString("keyMessagesId");
sendMessageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("messages", messageText.getText().toString()));
String response = null;
try {
linkurl = new Koneksi(ChatRoom.this);
SERVER_URL = linkurl.getUrl();
SERVER_URL += "/mobile/ChatKirimTeks.php?idu="+param2+"&idch="+param3;
response = CourseHttpClient.executeHttpPost(SERVER_URL, postParameters);
String res = response.toString();
res = res.trim();
res = res.replaceAll("\\s+","");
if(res.equals("1")){
String messageString = messageText.getText().toString();
showMessage(messageString, true);
messageText.getText().clear();
}else
{
createDialog("Maaf", "Messages Anda Gagal Terkirim");
}
}
catch (Exception e) {
messageText.setText(e.toString());
}
}
});
HttpURLConnection connection;
URL url = null;
try{
linkurl = new Koneksi(this);
SERVER_URL = linkurl.getUrl();
SERVER_URL += "/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
url = new URL(SERVER_URL);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestMethod("POST");
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(SERVER_URL);
//ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
//add parameter
//httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpRespose = httpClient.execute(httpPost);
HttpEntity httpEntity = httpRespose.getEntity();
//read content
InputStream in = httpEntity.getContent();
BufferedReader read = new BufferedReader(new InputStreamReader(in));
String msg = "tes";
while(true)
{
try {
msg = read.readLine();
Log.d("","MSGGG: "+ msg);
//msgList.add(msg);
} catch (IOException e) {
// TODO Auto-generated catch block
e.getMessage();
}
if(msg == null)
{
break;
}
else
{
showMessage(msg, false);
}
}}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public class ReceivedTask extends AsyncTask<String, String, String> {
@Override
protected void onPreExecute() {
}
@Override
protected String doInBackground(String... arg0) {
// TODO Auto-generated method stub
HttpURLConnection connection;
URL url = null;
try{
linkurl = new Koneksi(ChatRoom.this);
SERVER_URL = linkurl.getUrl();
SERVER_URL += "/mobile/ChatRoom.php?idu="+param2+"&idch="+param3+"&idcm="+param4;
url = new URL(SERVER_URL);
connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
connection.setRequestMethod("POST");
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(SERVER_URL);
//ArrayList<NameValuePair> param = new ArrayList<NameValuePair>();
//add parameter
//httpPost.setEntity(new UrlEncodedFormEntity(param));
HttpResponse httpRespose = httpClient.execute(httpPost);
HttpEntity httpEntity = httpRespose.getEntity();
//read content
InputStream in = httpEntity.getContent();
BufferedReader read = new BufferedReader(new InputStreamReader(in));
}
catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return null;
}
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
String msg = "tes";
while(true)
{
try {
msg = read.readLine();
Log.d("","MSGGG: "+ msg);
//msgList.add(msg);
} catch (IOException e) {
// TODO Auto-generated catch block
e.getMessage();
}
if(msg == null)
{
break;
}
else
{
showMessage(msg, false);
}
}
}
}
public void showMessage(String message, boolean leftSide) {
final TextView textView = new TextView(ChatRoom.this);
textView.setTextColor(Color.BLACK);
textView.setText(message);
int bgRes = R.drawable.left_message_bg;
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
if (!leftSide) {
bgRes = R.drawable.right_message_bg;
params.gravity = Gravity.RIGHT;
}
textView.setLayoutParams(params);
textView.setBackgroundResource(bgRes);
runOnUiThread(new Runnable() {
@Override
public void run() {
messagesContainer.addView(textView);
// Scroll to bottom
if (scrollContainer.getChildAt(0) != null) {
scrollContainer.scrollTo(scrollContainer.getScrollX(), scrollContainer.getChildAt(0).getHeight());
}
scrollContainer.fullScroll(View.FOCUS_DOWN);
}
});
}
private void createDialog(String title, String text) {
AlertDialog ad = new AlertDialog.Builder(this)
.setPositiveButton("Ok", null)
.setTitle(title)
.setMessage(text)
.create();
ad.show();
}
}
解决方案
You're getting the error message read cannot be resolved because Android forbids you to access the internet from the User Interface thread. You have to do that in a background thread. Indeed, the point of using AsyncTask is to keep the user interface thread as free as possible.
Whenever I use AsyncTask, I usually create a class to hold all the parameters of the task, and another class to hold the results. Also, I make sure that the results class can represent any error conditions that may occur, e.g. exceptions thrown. So the general template that I use looks something like this (NB: this is for when a progress report isn't required).
public class MyActivity extends Activity {
static class MyAsyncTaskParameters {
// put all the parameters that the task will need here
}
void KickOffAsynctask(...) { // various arguments as required by the task in hand
MyAsyncTaskParameters params = new MyAsyncTaskParameters(...); // package up all the parameters
MyAsyncTask newtask = new MyAsyncTask();
newtask.execute(params);
}
static class MyAsyncTaskResults {
// put all the results that the task can generate here
// NOTE: errors can occur in tasks, also exceptions
// can be thrown in tasks, so make it possible
// for this class to describe all error conditions that can occur
}
static class MyAsyncTask extends AsyncTask<MyAsyncTaskParameters, Void, MyAsyncTaskResults> {
@Override
protected MyAsyncTaskResults doInBackground(MyAsyncTaskParameters... params) {
MyAsyncTaskResults results = new MyAsyncTaskResults();
try {
MyAsyncTaskParameters taskParameters = params[0];
// This method will run in a background thread, so
// do as much as possible of the AsyncTask here.
} catch (Throwable e) {
// Set results object to indicate that an exception occurred.
}
return results;
}
@Override
protected void onPostExecute(MyAsyncTaskResults res) {
// This method will run in the User Interface thread.
// Use it to deal with the results stored in res.
// If an error has occurred, the res object will have it stored
// so take appropriate action, e.g. report to user.
}
}
}
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