Java 异步任务过程
我正在创建一个应用程序,当您使用用户名和密码登录时,它会从服务器请求信息。 服务器的请求需要时间(15-20秒),同时我想用几句话来展示一个旋转条。 但是我尝试了太多的Java 异步任务过程,java,android,multithreading,user-interface,android-asynctask,Java,Android,Multithreading,User Interface,Android Asynctask,我正在创建一个应用程序,当您使用用户名和密码登录时,它会从服务器请求信息。 服务器的请求需要时间(15-20秒),同时我想用几句话来展示一个旋转条。 但是我尝试了太多的AsyncTask类的变体,但我无法让它工作。它可以获得信息,但会冻结屏幕直到收到响应。 现在我有一个新线程实现了runnable。我不确定需要从代码的何处调用异步任务 onClick触发attemptLogin()函数: public void onClick(View view) { attemptLo
AsyncTask
类的变体,但我无法让它工作。它可以获得信息,但会冻结屏幕直到收到响应。
现在我有一个新线程实现了runnable
。我不确定需要从代码的何处调用异步任务
onClick
触发attemptLogin()
函数:
public void onClick(View view) {
attemptLogin();
}
// more code
showProgress(true);
new Thread(new GetServerResponseRunnable()).start();
while (wait) {}
// more code
public String getTours(String username, String password) {
String req = "GETALLDATA";
String retStr = "";
try {
url = getURL(req, username, password);
sendOutputLine(url, "");
retStr = getReturnString();
Log.d(LoginActivity.DEBUG_TAG, "getTours() return: " + retStr);
} catch (Exception e) {
Log.d(LoginActivity.DEBUG_TAG, "programm bommed client: " + e.getMessage());
}
return retStr;
}
在attemptLogin()函数中:
public void onClick(View view) {
attemptLogin();
}
// more code
showProgress(true);
new Thread(new GetServerResponseRunnable()).start();
while (wait) {}
// more code
public String getTours(String username, String password) {
String req = "GETALLDATA";
String retStr = "";
try {
url = getURL(req, username, password);
sendOutputLine(url, "");
retStr = getReturnString();
Log.d(LoginActivity.DEBUG_TAG, "getTours() return: " + retStr);
} catch (Exception e) {
Log.d(LoginActivity.DEBUG_TAG, "programm bommed client: " + e.getMessage());
}
return retStr;
}
可运行的是:
public class GetServerResponseRunnable implements Runnable {
@Override
public void run() {
response = getInfo.getTours(mUsername, mPassword);
wait = false;
}
}
正如您所看到的,从不同的类调用另一个函数。
这就是功能:
public void onClick(View view) {
attemptLogin();
}
// more code
showProgress(true);
new Thread(new GetServerResponseRunnable()).start();
while (wait) {}
// more code
public String getTours(String username, String password) {
String req = "GETALLDATA";
String retStr = "";
try {
url = getURL(req, username, password);
sendOutputLine(url, "");
retStr = getReturnString();
Log.d(LoginActivity.DEBUG_TAG, "getTours() return: " + retStr);
} catch (Exception e) {
Log.d(LoginActivity.DEBUG_TAG, "programm bommed client: " + e.getMessage());
}
return retStr;
}
我需要帮助,请。我主要想做的是:
response = getInfo.getTours(mUsername, mPassword);
wait = false;
同时展示旋转杆
谢谢
更新:02.13.2013
我用了这个密码,但我得到了一个
02-13 09:07:16.142: E/AndroidRuntime(1046): java.lang.NullPointerException
行中:
this.dialog.setMessage(getResources().getString(R.string.login_progress_signing_in));
知道为什么吗
public class LoginTask extends AsyncTask<Object, Void, String> {
public Context context;
public ProgressDialog dialog;
public void BaseTask(Context context) {
this.context = context;
this.dialog = new ProgressDialog(context);
}
@Override
protected void onPreExecute() {
this.dialog.setMessage(getResources().getString(R.string.login_progress_signing_in));
this.dialog.show();
}
@Override
protected String doInBackground(Object... objects) {
String name = (String) objects[0];
String password = (String) objects[1];
String response = getInfo.getTours(name , password );
return response;
}
@Override
protected void onPostExecute(String response) {
if (dialog != null && dialog.isShowing())
dialog.dismiss();
LoginActivity.response = response;
// process response as you need
}
}
公共类登录任务扩展异步任务{
公共语境;
公共对话;
公共void基任务(上下文){
this.context=上下文;
this.dialog=newprogressdialog(上下文);
}
@凌驾
受保护的void onPreExecute(){
this.dialog.setMessage(getResources().getString(R.string.login\u progress\u signing\u in));
this.dialog.show();
}
@凌驾
受保护的字符串doInBackground(对象…对象){
字符串名称=(字符串)对象[0];
字符串密码=(字符串)对象[1];
String response=getInfo.getTours(名称、密码);
返回响应;
}
@凌驾
受保护的void onPostExecute(字符串响应){
if(dialog!=null&&dialog.isShowing())
dialog.dismise();
LoginActivity.response=响应;
//根据需要处理响应
}
}
尝试实施android登录活动。
在ADT中的“创建新活动”下,选择“登录活动”
这将为您生成以下模板代码:
/**
* Activity which displays a login screen to the user, offering registration as
* well.
*/
public class LoginActivityTest extends Activity {
/**
* A dummy authentication store containing known user names and passwords.
* TODO: remove after connecting to a real authentication system.
*/
private static final String[] DUMMY_CREDENTIALS = new String[] {
"foo@example.com:hello", "bar@example.com:world" };
/**
* The default email to populate the email field with.
*/
public static final String EXTRA_EMAIL = "com.example.android.authenticatordemo.extra.EMAIL";
/**
* Keep track of the login task to ensure we can cancel it if requested.
*/
private UserLoginTask mAuthTask = null;
// Values for email and password at the time of the login attempt.
private String mEmail;
private String mPassword;
// UI references.
private EditText mEmailView;
private EditText mPasswordView;
private View mLoginFormView;
private View mLoginStatusView;
private TextView mLoginStatusMessageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_activity_test);
// Set up the login form.
mEmail = getIntent().getStringExtra(EXTRA_EMAIL);
mEmailView = (EditText) findViewById(R.id.email);
mEmailView.setText(mEmail);
mPasswordView = (EditText) findViewById(R.id.password);
mPasswordView
.setOnEditorActionListener(new TextView.OnEditorActionListener() {
@Override
public boolean onEditorAction(TextView textView, int id,
KeyEvent keyEvent) {
if (id == R.id.login || id == EditorInfo.IME_NULL) {
attemptLogin();
return true;
}
return false;
}
});
mLoginFormView = findViewById(R.id.login_form);
mLoginStatusView = findViewById(R.id.login_status);
mLoginStatusMessageView = (TextView) findViewById(R.id.login_status_message);
findViewById(R.id.sign_in_button).setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View view) {
attemptLogin();
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
getMenuInflater().inflate(R.menu.activity_login_activity_test, menu);
return true;
}
/**
* Attempts to sign in or register the account specified by the login form.
* If there are form errors (invalid email, missing fields, etc.), the
* errors are presented and no actual login attempt is made.
*/
public void attemptLogin() {
if (mAuthTask != null) {
return;
}
// Reset errors.
mEmailView.setError(null);
mPasswordView.setError(null);
// Store values at the time of the login attempt.
mEmail = mEmailView.getText().toString();
mPassword = mPasswordView.getText().toString();
boolean cancel = false;
View focusView = null;
// Check for a valid password.
if (TextUtils.isEmpty(mPassword)) {
mPasswordView.setError(getString(R.string.error_field_required));
focusView = mPasswordView;
cancel = true;
} else if (mPassword.length() < 4) {
mPasswordView.setError(getString(R.string.error_invalid_password));
focusView = mPasswordView;
cancel = true;
}
// Check for a valid email address.
if (TextUtils.isEmpty(mEmail)) {
mEmailView.setError(getString(R.string.error_field_required));
focusView = mEmailView;
cancel = true;
} else if (!mEmail.contains("@")) {
mEmailView.setError(getString(R.string.error_invalid_email));
focusView = mEmailView;
cancel = true;
}
if (cancel) {
// There was an error; don't attempt login and focus the first
// form field with an error.
focusView.requestFocus();
} else {
// Show a progress spinner, and kick off a background task to
// perform the user login attempt.
mLoginStatusMessageView.setText(R.string.login_progress_signing_in);
showProgress(true);
mAuthTask = new UserLoginTask();
mAuthTask.execute((Void) null);
}
}
/**
* Shows the progress UI and hides the login form.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
private void showProgress(final boolean show) {
// On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
// for very easy animations. If available, use these APIs to fade-in
// the progress spinner.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
int shortAnimTime = getResources().getInteger(
android.R.integer.config_shortAnimTime);
mLoginStatusView.setVisibility(View.VISIBLE);
mLoginStatusView.animate().setDuration(shortAnimTime)
.alpha(show ? 1 : 0)
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mLoginStatusView.setVisibility(show ? View.VISIBLE
: View.GONE);
}
});
mLoginFormView.setVisibility(View.VISIBLE);
mLoginFormView.animate().setDuration(shortAnimTime)
.alpha(show ? 0 : 1)
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mLoginFormView.setVisibility(show ? View.GONE
: View.VISIBLE);
}
});
} else {
// The ViewPropertyAnimator APIs are not available, so simply show
// and hide the relevant UI components.
mLoginStatusView.setVisibility(show ? View.VISIBLE : View.GONE);
mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
}
}
/**
* Represents an asynchronous login/registration task used to authenticate
* the user.
*/
public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {
@Override
protected Boolean doInBackground(Void... params) {
// TODO: attempt authentication against a network service.
try {
// Simulate network access.
Thread.sleep(2000);
} catch (InterruptedException e) {
return false;
}
for (String credential : DUMMY_CREDENTIALS) {
String[] pieces = credential.split(":");
if (pieces[0].equals(mEmail)) {
// Account exists, return true if the password matches.
return pieces[1].equals(mPassword);
}
}
// TODO: register the new account here.
return true;
}
@Override
protected void onPostExecute(final Boolean success) {
mAuthTask = null;
showProgress(false);
if (success) {
finish();
} else {
mPasswordView
.setError(getString(R.string.error_incorrect_password));
mPasswordView.requestFocus();
}
}
@Override
protected void onCancelled() {
mAuthTask = null;
showProgress(false);
}
}
}
/**
*向用户显示登录屏幕的活动,提供注册为
*嗯。
*/
公共类LoginActivityTest扩展活动{
/**
*包含已知用户名和密码的虚拟身份验证存储。
*TODO:连接到真实身份验证系统后删除。
*/
私有静态最终字符串[]伪\u凭据=新字符串[]{
"foo@example.com:你好“bar@example.com:世界“};
/**
*用于填充电子邮件字段的默认电子邮件。
*/
public static final String EXTRA_EMAIL=“com.example.android.authenticatordemo.EXTRA.EMAIL”;
/**
*跟踪登录任务,确保我们可以根据请求取消它。
*/
private UserLoginTask mAuthTask=null;
//尝试登录时的电子邮件和密码值。
私有字符串mEmail;
私有字符串mPassword;
//用户界面引用。
私有编辑文本mEmailView;
私有编辑文本mPasswordView;
私有视图mloginfo视图;
私有视图mLoginStatusView;
私有文本视图mLoginStatusMessageView;
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity\u login\u activity\u test);
//设置登录表单。
mEmail=getIntent().getStringExtra(额外电子邮件);
mEmailView=(EditText)findViewById(R.id.email);
mEmailView.setText(mEmail);
mPasswordView=(EditText)findViewById(R.id.password);
mPasswordView
.setOnEditorActionListener(新的TextView.OnEditorActionListener(){
@凌驾
公共布尔onEditorAction(TextView TextView,int-id,
KeyEvent(关键事件){
if(id==R.id.login | | id==EditorInfo.IME_NULL){
尝试登录();
返回true;
}
返回false;
}
});
mLoginFormView=findviewbyd(R.id.login\u表单);
mLoginStatusView=findviewbyd(R.id.login\u状态);
mLoginStatusMessageView=(TextView)findviewbyd(R.id.login\u status\u message);
findViewById(R.id.sign_in_按钮)。setOnClickListener(
新建视图。OnClickListener(){
@凌驾
公共void onClick(视图){
尝试登录();
}
});
}
@凌驾
公共布尔onCreateOptions菜单(菜单){
super.onCreateOptions菜单(菜单);
getMenuInflater().充气(R.menu.activity\u login\u activity\u test,menu);
返回true;
}
/**
*尝试登录或注册登录表单指定的帐户。
*如果存在表单错误(无效电子邮件、缺少字段等),则
*出现错误,未进行实际登录尝试。
*/
public void attemptLogin(){
if(mAuthTask!=null){
返回;
}
//重置错误。
mEmailView.setError(null);
mPasswordView.setError(null);
//在尝试登录时存储值。
mEmail=mEmailView.getText().toString();
mPassword=mPasswordView.getText().toString();
布尔取消=假;
视图焦点视图=空;
//检查密码是否有效。
if(TextUtils.isEmpty(mPassword)){
mPasswordView.setError(getString(R.string.error_字段_必填));