我使用AsynkTask从服务器获取数据工作正常，但我想在AsynkTask中使用处理程序来减少主线程的负载。我如何在AsynkTask中使用Handler。请帮我解决这个问题。
这是我的代码。
public class CLoginScreen extends Fragment {
public static String s_szLoginUrl = "http://192.168.0.999:8080/rest/json/metallica/getLoginInJSON";
public static String s_szresult = " ";
public static String s_szMobileNumber, s_szPassword;
public static String s_szResponseMobile, s_szResponsePassword;
public View m_Main;
public EditText m_InputMobile, m_InputPassword;
public AppCompatButton m_LoginBtn, m_ChangePass, m_RegisterBtn;
public CJsonsResponse m_oJsonsResponse;
public boolean isFirstLogin;
public JSONObject m_oResponseobject;
public LinearLayout m_MainLayout;
public CLoginSessionManagement m_oLoginSession;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
m_Main = inflater.inflate(R.layout.login_screen, container, false);
((AppCompatActivity) getActivity()).getSupportActionBar().hide();
m_oLoginSession = new CLoginSessionManagement(getActivity());
init();
return m_Main;
}
public void init() {
m_MainLayout = (LinearLayout) m_Main.findViewById(R.id.mainLayout);
m_InputMobile = (EditText) m_Main.findViewById(R.id.input_mobile);
m_InputPassword = (EditText) m_Main.findViewById(R.id.input_password);
m_LoginBtn = (AppCompatButton) m_Main.findViewById(R.id.btn_Login);
m_ChangePass = (AppCompatButton) m_Main.findViewById(R.id.btn_ChangePass);
m_ChangePass.setBackgroundColor(Color.TRANSPARENT);
m_ChangePass.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getActivity().getSupportFragmentManager().beginTransaction().replace(R.id.container, new CChangePasswordScreen()).commit();
}
});
m_RegisterBtn = (AppCompatButton) m_Main.findViewById(R.id.btn_Register);
m_RegisterBtn.setBackgroundColor(Color.TRANSPARENT);
m_RegisterBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getActivity().getSupportFragmentManager().beginTransaction().replace(R.id.container, new CRegistrationScreen()).commit();
}
});
m_LoginBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new LoginAttempt().execute();
}
});
}
private class LoginAttempt extends AsyncTask<String, Void, String> {
public Dialog m_Dialog;
public ProgressBar m_ProgressBar;
@Override
protected void onPreExecute() {
super.onPreExecute();
m_Dialog = new Dialog(getActivity());
m_Dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
m_Dialog.setContentView(R.layout.progress_bar);
showProgress("Please wait while Logging...");// showing progress ..........
}
@Override
protected String doInBackground(String... params) {
getLoginDetails();// getting login details from editText...........
InputStream inputStream = null;
m_oJsonsResponse = new CJsonsResponse();
isFirstLogin = true;
try {
// 1. create HttpClient
HttpClient httpclient = new DefaultHttpClient();
// 2. make POST request to the given URL
HttpPost httpPost = new HttpPost(s_szLoginUrl);
String json = "";
// 3. build jsonObject
JSONObject jsonObject = new JSONObject();
jsonObject.put("agentCode", s_szMobileNumber);
jsonObject.put("pin", s_szPassword);
jsonObject.put("firstloginflag", m_oLoginSession.isLogin());
// 4. convert JSONObject to JSON to String
json = jsonObject.toString();
// 5. set json to StringEntity
StringEntity se = new StringEntity(json);
// 6. set httpPost Entity
httpPost.setEntity(se);
// 7. Set some headers to inform server about the type of the content
// httpPost.setHeader("Accept", "application/json"); ///not required
httpPost.setHeader("Content-type", "application/json");
// 8. Execute POST request to the given URL
HttpResponse httpResponse = httpclient.execute(httpPost);
HttpEntity entity = httpResponse.getEntity();
// 9. receive response as inputStream
inputStream = entity.getContent();
System.out.print("InputStream...." + inputStream.toString());
System.out.print("Response...." + httpResponse.toString());
StatusLine statusLine = httpResponse.getStatusLine();
System.out.print("statusLine......" + statusLine.toString());
////Log.d("resp_body", resp_body.toString());
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
// 10. convert inputstream to string
if (inputStream != null) {
s_szresult = m_oJsonsResponse.convertInputStreamToString(inputStream);
//String resp_body =
EntityUtils.toString(httpResponse.getEntity());
}
} else
s_szresult = "Did not work!";
} catch (Exception e) {
Log.d("InputStream", e.getLocalizedMessage());
}
System.out.println("s_szResult....." + s_szresult);
System.out.println("password......" + s_szPassword);
// 11. return s_szResult
return s_szresult;
}
@Override
protected void onPostExecute(String response) {
super.onPostExecute(response);
hideProgress();// hide progressbar after getting response from server......
try {
m_oResponseobject = new JSONObject(response);// getting response from server
new Thread() {// making child thread...
public void run() {
Looper.prepare();
try {
getResponse();// getting response from server
Looper.loop();
} catch (JSONException e) {
e.printStackTrace();
}
}
}.start();
} catch (JSONException e) {
e.printStackTrace();
}
}
public void getResponse() throws JSONException {
if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Transaction Successful")) {
m_oLoginSession.setLoginData(s_szResponseMobile, s_szResponsePassword);
getActivity().getSupportFragmentManager().beginTransaction().replace(R.id.container, new CDealMainListing()).commit();
} else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Agentcode Can Not Be Empty")) {
showToast("Please Enter Valid Mobile Number");
} else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Pin Can Not Be Empty")) {
showToast("Please Enter Password");
} else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Invalid PIN")) {
showToast("Invalid Password");
} else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Subscriber/Agent Blocked due to Wrong Attempts")) {
showToast("You are blocked as You finished you all attempt");
} else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Connection Not Available")) {
showToast("Connection Lost ! Please Try Again");
} else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("Subscriber/Agent Not Found")) {
showToast("User not found ! Kindly Regiter before Login");
} else if (m_oResponseobject.getString("resultdescription").equalsIgnoreCase("OTP not verify")) {
showToast("Otp not Verify ! Kindly Generate Otp on Sign Up");
}
}
public void showToast(String message) {// method foe showing taost message
Toast toast = Toast.makeText(getActivity(), "" + message, Toast.LENGTH_SHORT);
toast.setGravity(Gravity.CENTER, 0, 0);
toast.show();
}
public void getLoginDetails() {
s_szMobileNumber = m_InputMobile.getText().toString();
s_szPassword = m_InputPassword.getText().toString();
}
public void showProgress(String message) {
m_ProgressBar = (ProgressBar) m_Dialog.findViewById(R.id.progress_bar);
TextView progressText = (TextView) m_Dialog.findViewById(R.id.progress_text);
progressText.setText("" + message);
progressText.setVisibility(View.VISIBLE);
m_ProgressBar.setVisibility(View.VISIBLE);
m_ProgressBar.setIndeterminate(true);
m_Dialog.setCancelable(false);
m_Dialog.setCanceledOnTouchOutside(false);
m_Dialog.show();
}
public void hideProgress() {
m_Dialog.dismiss();
}
}
}
答案 0 :(得分：0)
您可以使用
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
getResponse();
}
});
答案 1 :(得分：0)
根据android docs here
异步任务由在a上运行的计算定义 后台线程，其结果发布在UI线程上。
使用Handler从URL加载数据并不是一件好事。而是使用Executor或ThreadPoolExecutor来完成繁重的后台任务。
答案 2 :(得分：0)
main在你的片段中，你可以初始化一个处理程序作为MyAsyncTask的参数，并处理你在handleMessage（）中的工作;