在我的应用中，我们有一个EnterPin活动，可以将引脚保存在SharedPreference中，并将其与您输入的内容进行比较。如果它是正确的，意图会将您带到MainActivity并传递一个带有键的真正布尔值＆＃34;已验证＆＃34;
出于某种原因，在模拟器和我的s7上，输入正确的引脚（通过调试确认）后，它只是重新启动EnterPinActivity。
最令人讨厌的部分是它有时会起作用，有时却不起作用。我不明白可能导致这个问题的原因。
EnterPin.java
public class EnterPin extends AppCompatActivity {
//Used to check if there is a pin
SharedPreferences preferences;
//Title of the private file for the pin
public final String PINFILE = "PinFile";
private int pin;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_enter_pin);
pin = getPinFromFile();
//TODO::add similar check for security questions in case they exit the app during creation
//If the user did not create a pin, send to create one and end this activity
if(pin == -1) {
forceCreatePin();
finish();
}
Button logBtn = (Button)findViewById(R.id.logBtn);
Button forgotBtn = (Button)findViewById(R.id.forgotPin);
}
public void onClick(View v){
if(v.getId() == R.id.logBtn){
EditText pinIn = (EditText) findViewById(R.id.enterPin);
String pinStr = pinIn.getText().toString();
if (pinStr.length() == 4) {
int pinInt = Integer.parseInt(pinStr);
if (pin == pinInt) {
//Login
Intent intent = new Intent(getApplicationContext(), MainActivity.class);
intent.putExtra("verified", true);
startActivity(intent);
finish();
} else {
//clear input and notify user of wrong pin
pinIn.setText("");
Toast toast = Toast.makeText(getApplicationContext(), "Incorrect PIN", Toast.LENGTH_SHORT);
toast.show();
}
} else {
pinIn.setText("");
Toast toast = Toast.makeText(getApplicationContext(), "PIN must be 4 characters", Toast.LENGTH_SHORT);
toast.show();
}
}else if(v.getId() == R.id.forgotPin){
Intent intent = new Intent(getApplicationContext(), ForgotPIN.class);
startActivity(intent);
finish();
}
}
private int getPinFromFile() {
preferences = getSharedPreferences(PINFILE, MODE_PRIVATE);
//Returns value at key "pin" if it exists, -1 if pin is not created
return preferences.getInt(PINFILE, -1);
}
private void forceCreatePin() {
Intent intent = new Intent(this, CreatePin.class);
startActivity(intent);
}
}
MainActivity.java
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//get verified key from intent activity was started with, set false if key not found
isVerified = getIntent().getBooleanExtra("verified", false);
if (!isVerified) {
forceEnterPin();
}
//We create the db in the main class
try {
db = this.openOrCreateDatabase("budgetDB", MODE_PRIVATE, null);
System.out.println("Succes!!!!!!!");
}
catch(Exception e)
{
System.out.println("It got caught....");
Log.e("BudgetDatabase ERROR", "Error Creating/Loading database");
}
Database budDB = new Database(db);
budDB.createTables();
//Loading variables, settings the first fragment to the home screen
spendableInc = loadSpendableInc();
FragmentTransaction trans = getFragmentManager().beginTransaction();
HomeFragment homeFragment = new HomeFragment();
trans.add(R.id.frag_container, homeFragment, "home").commit();
//Settings functionality for the bottom navigation bar
final FrameLayout frameLayout = (FrameLayout) findViewById(R.id.frag_container);
BottomNavigationView bottomNavigationView = (BottomNavigationView) findViewById(R.id.bottom_navigation);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
FragmentManager manager = getFragmentManager();
final FragmentTransaction transaction = manager.beginTransaction();
//Handling clicks on home, transaction, or overview
switch (item.getItemId()) {
case R.id.action_home:
HomeFragment homeFragment = new HomeFragment();
transaction.replace(R.id.frag_container, homeFragment, "home").commit();
break;
case R.id.action_transactions:
TransactionFragment transactionFragment = new TransactionFragment();
transaction.replace(R.id.frag_container, transactionFragment, "transaction").commit();
break;
case R.id.action_overview:
OverviewFragment overviewFragment = new OverviewFragment();
transaction.replace(R.id.frag_container, overviewFragment, "overview").commit();
break;
}
return false;
}
});
}
/**
* Auto-generated method for toolbar
* @param menu
* @return
*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
/**
* Auto-generated method for toolbar
* @param item
* @return
*/
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
} else if (id == R.id.logout) {
forceEnterPin();
return true;
}
return super.onOptionsItemSelected(item);
}
public void saveSpendableInc(float amt) {
SharedPreferences.Editor editor = getSharedPreferences(SPENDABLE_INCOME, MODE_PRIVATE).edit();
editor.putFloat(SPENDABLE_INCOME, amt);
editor.commit();
}
public float loadSpendableInc() {
SharedPreferences prefs = getSharedPreferences(SPENDABLE_INCOME, MODE_PRIVATE);
return prefs.getFloat(SPENDABLE_INCOME, MODE_PRIVATE);
}
public void createIncome(View view) {
Intent intent = new Intent(this, CreateIncome.class);
intent.putExtra(SPENDABLE_INCOME, spendableInc);
startActivity(intent);
}
public void createExpense(View view) {
Intent intent = new Intent(this, CreateExpense.class);
intent.putExtra(SPENDABLE_INCOME, spendableInc);
startActivity(intent);
}
/**
* Closes the database when the application is terminated
* Set verified to false to force
*/
@Override
protected void onDestroy(){
super.onDestroy();
db.close();
getIntent().putExtra("verified", false);
idleStart = 0;
idleFinish = 0;
}
//Forces user to create pin and ends the main activity so the user can't use the back button to get to home screen
private void forceEnterPin() {
getIntent().putExtra("verified", false);
Intent intent = new Intent(this, EnterPin.class);
startActivity(intent);
//finish();
}
@Override
protected void onPause(){
super.onPause();
Calendar tmpCalendar = Calendar.getInstance();
idleStart = tmpCalendar.get(Calendar.MINUTE);
}
@Override
protected void onStop(){
super.onStop();
Calendar tmpCalendar = Calendar.getInstance();
//If app went straight to stop phase, start at 0
//If app started at pause and then went to stop, add time from before
if(idleStart == 0)
idleStart = tmpCalendar.get(Calendar.MINUTE);
else
idleStart += tmpCalendar.get(Calendar.MINUTE);
}
@Override
protected void onResume(){
super.onResume();
//Use calendar object to get the current time in minutes
Calendar tmpCalendar = Calendar.getInstance();
idleFinish = tmpCalendar.get(Calendar.MINUTE);
if(idleFinish - idleStart >= 30)
forceEnterPin();
//Reset idle times because user started app again
idleStart = 0;
idleFinish = 0;
}
}
答案 0 :(得分：-1)
答案：在您开始为您开展活动之前，请先阅读您使用的API。