我应该在哪里以及在哪里添加代码才能使其正常工作？ 默认情况下，它不执行任何操作，按钮显示“登录或注册”，但它不显示任何注册活动。 菜单中的“恢复丢失的密码”也没有任何作用。 通过在finish（）之后创建一个intent，我设法在签名后打开一个新活动; 虽然它无论电子邮件和密码如何都能成功登录！
public class LoginActivity 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[] CREDENTIALS = new String[]
{
"myaccount1@gmail.com:12345", "myaccount2@gmail.com:54321"
};
/**
* The default email to populate the email field with.
*/
public static final String EXTRA_EMAIL = "myaccount1@gmail.com";
/**
* 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);
// 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, 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 : 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.
//CREDENTIALS[2]=mEmail+":"+mPassword; tried this for regisration
return true;
}
@Override
protected void onPostExecute(final Boolean success)
{
mAuthTask = null;
showProgress(false);
if (success)
{
finish();
Intent myIntent = new Intent(LoginActivity.this,CalculatorActivity.class);
LoginActivity.this.startActivity(myIntent);
} else
{
mPasswordView
.setError(getString(R.string.error_incorrect_password));
mPasswordView.requestFocus();
}
}
@Override
protected void onCancelled()
{
mAuthTask = null;
showProgress(false);
}
}
}
这适用于CREDENTIALS中的默认字符串，但我不知道如何实现注册过程，如何将这些mEmail和mPassword添加到CREDENTIALS字符串？
答案 0 :(得分：1)
CREDENTIALS只是在程序的前几行中定义的字符串数组，您可以手动编辑它。例如：
private static final String[] CREDENTIALS = new String[]
{
"myaccount1@gmail.com:12345", "myaccount2@gmail.com:54321", "bla@bla.com:1234"
};
但是这个模板代码用于登录Web服务数据库或类似的东西。如果你想登录本地数据库，你不需要AsyncTask mumbo jumbo，你可以在attempt！= true时在trylogin（）函数中编写验证码。