我的应用程序包含一个初始的启动画面,后面是一个列表视图(主活动)。单击
我的要求是,如果我们从任何内部活动(单击
因此,如果我两次从我的
这是退出应用程序的代码。 我在我的主
listview
中的每一行将打开每个活动。我的要求是,如果我们从任何内部活动(单击
listview
行时打开的活动)单击返回按钮,则必须导航到我的主listview
,然后再次从listview
单击一次以关闭应用程序。因此,如果我两次从我的
listview
按下返回按钮,它将正确退出应用程序。我的主要问题是,如果我从任何内部活动两次按下返回按钮,我的应用程序不会关闭。我需要按三次,而不是从任何内部活动关闭应用程序。请问有人可以帮助我吗?这是退出应用程序的代码。 我在我的主
listview
类中添加了这段代码。private static final int TIME_INTERVAL = 3000; // # milliseconds, desired time passed between two back presses.
private long mBackPressed;
@Override
public void onBackPressed()
{
if (mBackPressed + TIME_INTERVAL > System.currentTimeMillis())
{
super.onBackPressed();
return;
}
else { Toast.makeText(getBaseContext(), "Tap back button in order to exit", Toast.LENGTH_SHORT).show(); }
mBackPressed = System.currentTimeMillis();
}
}
我的manifest.xml
<application
android:allowBackup="true"
android:label="@string/app_name"
android:theme="@style/AppTheme">
<meta-data android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version"/>
<activity
android:name="learnersseries.mathematics.complexnumbers.Firstintro"
android:screenOrientation="portrait"
android:launchMode="singleTop"
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="Myintegralpage"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="myimagine"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="Myintroductionpage"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="MainActivity"
android:noHistory="false"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="Complexnumbers"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="Equality"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="Additionofcomplex"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="Subtraction"
android:screenOrientation="portrait"
>
<intent-filter></intent-filter>
</activity>
<activity android:name="multiplication"
android:screenOrientation="portrait" >
<intent-filter></intent-filter>
</activity>
<activity android:name="Division"
android:screenOrientation="portrait" >
<intent-filter></intent-filter>
</activity>
<activity android:name="Conjugate"
android:screenOrientation="portrait" >
<intent-filter></intent-filter>
</activity>
<activity android:name="Modulus"
android:screenOrientation="portrait" >
<intent-filter></intent-filter>
</activity>
<activity android:name="Reciprocal"
android:screenOrientation="portrait" >
<intent-filter></intent-filter>
</activity>
<activity android:name="Square"
android:screenOrientation="portrait">
</activity>
<activity android:name="Representation"
android:screenOrientation="portrait" >
<intent-filter></intent-filter>
</activity>
<activity android:name="Argument"
android:screenOrientation="portrait" >