Программа Android открывает QR-сканер несколько раз

Question

У меня есть приложение, где на экране входа у меня есть кнопка QR-сканера. Когда пользователь нажимает кнопку, открывается приложение QR-сканера и после сканирования он тост сообщения пользователю.

В настоящее время при нажатии кнопки открывается QR-сканер и он может захватывать данные с QR-кода, но он снова открывается. Вот образец исполнения:

1. QR scanner opens. reads the QR code (as expected) 
<after this point everything is wrong> 
2. QR scanner opens again. 
3. My main_screen comes back 
4. QR scanner opens again and i read QR code. 
5. My main screen comes back 

Может кто-то пожалуйста, помогите: Вот мои файлы:

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.example.amandeepsingh.loyaltyapp2" > 

<application 
    android:allowBackup="true" 
    android:icon="@mipmap/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name=".SplashScreenActivity" 
     android:label="@string/app_name" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
<activity android:name=".MainActivity" > 
</activity> 
    <activity 
     android:name=".Login" 
     android:label="@string/title_activity_login" > 
    </activity> 
    <activity 
     android:name=".Register" 
     android:label="@string/title_activity_register" > 
    </activity> 
    <!--added for QR codes scanner--> 
    <activity android:name=".AndroidBarcodeQrExample"/> 
    <!-- QR code ends here--> 
</application> 

</manifest> 

Это мой файл макета:

activity_main .xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:orientation="vertical" 
android:padding="10dp" 
android:background="@drawable/androidrain" 
tools:context="com.example.amandeepsingh.loyaltyapp2.Login"> 

<TextView 
    android:layout_width="wrap_content" 
    android:text="Email" 
    android:textColor="#FFFFFF" 
    android:layout_height="wrap_content" /> 

<EditText 
    android:id="@+id/etEmail" 
    android:layout_width="match_parent" 
    android:layout_marginBottom="10dp" 
    android:textColor="#FFFFFF" 
    android:layout_height="wrap_content" /> 

<TextView 
    android:layout_width="wrap_content" 
    android:text="Phone Number" 
    android:textColor="#FFFFFF" 
    android:layout_height="wrap_content" /> 

<EditText 
    android:id="@+id/etPhoneNumber" 
    android:layout_width="match_parent" 
    android:layout_marginBottom="10dp" 
    android:textColor="#FFFFFF" 
    android:layout_height="wrap_content" /> 


<Button 
    android:id="@+id/bLogOut" 
    android:text="LogOut" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" /> 

<Button 
    android:id="@+id/bEarnPoints" 
    android:layout_width="250dp" 
    android:layout_height="80dp" 
    android:layout_gravity="center" 
    android:layout_margin="10dp" 
    android:gravity="center" 

    android:text="Earn Points" 
    android:textSize="18dp" > 
</Button> 

<Button 
    android:id="@+id/bRedeamPoints" 
    android:layout_width="250dp" 
    android:layout_height="80dp" 
    android:layout_gravity="center" 
    android:layout_margin="10dp" 
    android:gravity="center" 

    android:text="Redeam Points" 
    android:textSize="18dp" > 
</Button> 

</LinearLayout> 

Это код, из которого я поставил QR код кнопки сканера:

MainActivity.java

public class MainActivity extends Activity implements View.OnClickListener{ 

Button bLogOut; 
EditText etEmail,etPhoneNumber; 
//this is for having access to userlocalstore to save/remove local data to user phone during log inor Log out. So that if logout is pressed 
//the data is wiped off the local storage on user mobile 
UserLocalStore userLocalStore; 

//added for QR codes scanner 
Button bEarnPoints,bRedeamPoints; 
//QR code scanner ends 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    etEmail= (EditText)findViewById(R.id.etEmail); 
    etPhoneNumber =(EditText)findViewById(R.id.etPhoneNumber); 
    bLogOut = (Button)findViewById(R.id.bLogOut); 

    bLogOut.setOnClickListener(this); 

    userLocalStore = new UserLocalStore(this); 
    //added for QR codes scanner 
    bEarnPoints=(Button)findViewById(R.id.bEarnPoints); 
    bRedeamPoints=(Button)findViewById(R.id.bRedeamPoints); 
    bEarnPoints.setOnClickListener(this); 
    bRedeamPoints.setOnClickListener(this); 
    //QR code ends here 
} 

@Override 
public void onClick(View v) { 
    switch(v.getId()){ 
     case R.id.bLogOut: 
      userLocalStore.clearUserData(); 
      userLocalStore.setUserLoggedIn(false); 

      startActivity(new Intent(this,Login.class)); 

      break; 

     //added for QR codes scanner 
     case R.id.bEarnPoints: 
      startActivity(new Intent(this,AndroidBarcodeQrExample.class)); 
      break; 

     case R.id.bRedeamPoints: 
      startActivity(new Intent(this,AndroidBarcodeQrExample.class)); 
      break; 

     //QR ends here 
    } 

} 

@Override 
protected void onStart() { 
    super.onStart(); 

    if (authenticate() == true) { 
     displayUserDetails(); 
    } 
} 

public boolean authenticate(){ 
    return userLocalStore.getUserLoggedIn(); 
} 

public void displayUserDetails(){ 
    User user = userLocalStore.getLoggedInUser(); 
    etEmail.setText(user.Email); 
    etPhoneNumber.setText(user.PhoneNumber+""); 

} 

//code below this is not being used 
@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; 
} 

@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; 
    } 

    return super.onOptionsItemSelected(item); 
} 
} 

и это код QRScanner:

AndroidBarcodeQrExample.java

public class AndroidBarcodeQrExample extends Activity { 
/** Called when the activity is first created. */ 

static final String ACTION_SCAN = "com.google.zxing.client.android.SCAN"; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    scanQR(); 
} 

public void scanBar(View v) { 
    try { 
     Intent intent = new Intent(ACTION_SCAN); 
     intent.putExtra("SCAN_MODE", "PRODUCT_MODE"); 
     startActivityForResult(intent, 0); 
    } catch (ActivityNotFoundException anfe) { 
     showDialog(AndroidBarcodeQrExample.this, "No Scanner Found", "Download a scanner code activity?", "Yes", "No").show(); 
    } 
} 

public void scanQR() { 
    try { 
     Intent intent = new Intent(ACTION_SCAN); 
     intent.putExtra("SCAN_MODE", "QR_CODE_MODE"); 
     startActivityForResult(intent, 0); 
    } catch (ActivityNotFoundException anfe) { 
     showDialog(AndroidBarcodeQrExample.this, "No Scanner Found", "Download a scanner code activity?", "Yes", "No").show(); 
    } 
} 

private static AlertDialog showDialog(final Activity act, CharSequence title, CharSequence message, CharSequence buttonYes, CharSequence buttonNo) { 
    AlertDialog.Builder downloadDialog = new AlertDialog.Builder(act); 
    downloadDialog.setTitle(title); 
    downloadDialog.setMessage(message); 
    downloadDialog.setPositiveButton(buttonYes, new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialogInterface, int i) { 
      Uri uri = Uri.parse("market://search?q=pname:" + "com.google.zxing.client.android"); 
      Intent intent = new Intent(Intent.ACTION_VIEW, uri); 
      try { 
       act.startActivity(intent); 
      } catch (ActivityNotFoundException anfe) { 

      } 
     } 
    }); 
    downloadDialog.setNegativeButton(buttonNo, new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialogInterface, int i) { 
     } 
    }); 
    return downloadDialog.show(); 
} 

public void onActivityResult(int requestCode, int resultCode, Intent intent) { 
    if (requestCode == 0) { 
     if (resultCode == RESULT_OK) { 
      String contents = intent.getStringExtra("SCAN_RESULT"); 
      String format = intent.getStringExtra("SCAN_RESULT_FORMAT"); 

      Toast toast = Toast.makeText(this, "Content:" + contents + " Format:" + format, Toast.LENGTH_LONG); 
      toast.show(); 
     } 
    } 
} 
} 

Пожалуйста, помогите с несколькими ненужными проблемами открытия QR-сканера.

Заранее благодарен!

Answer 1

В AndroidBarcodeQrExample Oncreate вы запускаете намерение без каких-либо условий.

public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     scanQR(); // here everytime it starts an activity again and again. 
    } 

Основываясь на каком-то определенном состоянии, вы должны начать свое намерение.