为每一个活动写这个到你的清单文件:

android:screenOrientation="portrait" 

好吧, 我试了所有的答案，但在旧版本的安卓系统上都不行。 所以，最终的解决方案是将这段代码添加到setContentView上面的每个活动:

    setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

对于Xamarin用户:

如果你把你所有的活动扩展到一个BaseActivity，只需添加:

this.RequestedOrientation = ScreenOrientation.Portrait;

这样问题就解决了。如果你想要任何特定的活动在横向覆盖OnActivityCreated。为:

this.Activity.RequestedOrientation = ScreenOrientation.Landscape;

将android:screenOrientation="portrait"添加到AndroidManifest.xml中的活动中。例如:

<activity android:name=".SomeActivity"
    android:label="@string/app_name"
    android:screenOrientation="portrait">

来自Android开发者指南:

"orientation" The screen orientation has changed — the user has rotated the device. Note: If your application targets API level 13 or higher (as declared by the minSdkVersion and targetSdkVersion attributes), then you should also declare the "screenSize" configuration, because it also changes when a device switches between portrait and landscape orientations. "screenSize" The current available screen size has changed. This represents a change in the currently available size, relative to the current aspect ratio, so will change when the user switches between landscape and portrait. However, if your application targets API level 12 or lower, then your activity always handles this configuration change itself (this configuration change does not restart your activity, even when running on an Android 3.2 or higher device). Added in API level 13.

所以，在AndroidManifest.xml文件中，我们可以放:

<activity
            android:name=".activities.role_activity.GeneralViewPagerActivity"
            android:label="@string/title_activity_general_view_pager"
            android:screenOrientation="portrait"
            android:configChanges="orientation|keyboardHidden|screenSize"
            >
        </activity> 

如果有人想知道，如何为整个应用程序做到这一点，而不必让所有活动都扩展Kotlin中的公共基类， 请看下面的例子:

class InteractiveStoryApplication: Application() {
override fun onCreate() {
    super.onCreate()
    registerActivityLifecycleCallbacks(object: ActivityLifecycleCallbacks {
        override fun onActivityCreated(activity: Activity?, savedInstanceState: Bundle?) {
            activity?.requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_PORTRAIT
        }

        override fun onActivityPaused(activity: Activity?) {
        }

        override fun onActivityResumed(activity: Activity?) {
        }

        override fun onActivityDestroyed(activity: Activity?) {
        }

        override fun onActivitySaveInstanceState(activity: Activity?, outState: Bundle?) {
        }

        override fun onActivityStarted(activity: Activity?) {
        }

        override fun onActivityStopped(activity: Activity?) {
        }
    })
}
}

然后你必须像这样在AndroidManifest中添加你的公共基类:

<application android:allowBackup="true"
android:name=".InteractiveStoryApplication"