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;

为每一个活动写这个到你的清单文件:

android:screenOrientation="portrait" 

在你的Manifest中输入:

<activity
    android:screenOrientation="portrait"
    <!--- Rest of your application information ---!>
</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"

你可以在你的manifest文件中设置这个。

android:name=".your launching activity name"
android:screenOrientation="portrait"

你也可以通过在你的类文件中写这样的代码来达到同样的目的:

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

在kotlin——>

在你的Extends Application类中使用这个onCreate()…

registerActivityLifecycleCallbacks(object : ActivityLifecycleCallbacks {
        override fun onActivityCreated(p0: Activity, p1: Bundle?) {
            p0.requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE;
        }

        override fun onActivityStarted(p0: Activity) {
        }

        override fun onActivityResumed(p0: Activity) {
        }

        override fun onActivityPaused(p0: Activity) {
        }

        override fun onActivityStopped(p0: Activity) {
        }

        override fun onActivitySaveInstanceState(p0: Activity, p1: Bundle) {
        }

        override fun onActivityDestroyed(p0: Activity) {
        }
    }

    )}