尝试setText时，空指针异常（Android studio）

Question

我一直有一个奇怪的问题，我尝试创建一个与以往完全相同的textView，但现在当我初始化textView和setText时，我得到一个空指针异常，并且无法弄清楚我做错了什么。

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

TextView test = (TextView) findViewById(R.id.randomID);
test.setText("sample text");
}

XML

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/Constraint"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:openDrawer="start">

<RelativeLayout
    android:id="@+id/relativeLayout"
    android:layout_width="364dp"
    android:layout_height="223dp"
    android:layout_marginBottom="8dp"
    android:layout_marginEnd="8dp"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="@+id/cityID"
    app:layout_constraintVertical_bias="0.006">

    <ImageView
        android:id="@+id/weatherImage"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginBottom="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toLeftOf="@+id/celsius"
        app:layout_constraintTop_toBottomOf="@+id/loadingLocation"
        app:layout_constraintVertical_bias="0.555"
        app:srcCompat="@drawable/thunder_cloud_rain"/>
</RelativeLayout>

<android.support.v7.widget.Toolbar
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/settingsToolbar"
    android:titleTextColor="@color/white"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginBottom="8dp"
    android:background="@color/colorPrimary"
    android:minHeight="?android:attr/actionBarSize"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.0"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.0"
    app:theme="@style/ToolBarStyle"/>

<TextView
    android:id="@+id/celsius"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginBottom="8dp"
    android:layout_marginEnd="8dp"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="45sp"
    android:textStyle="bold"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.0"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/settingsToolbar"
    app:layout_constraintVertical_bias="0.035"
    tools:text="96"/>

<TextView
    android:id="@+id/skyForecast"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginBottom="7dp"
    android:gravity="center"
    android:includeFontPadding="false"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="14sp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    tools:text="Scattered Clouds"
    app:layout_constraintHorizontal_bias="1.0"
    android:layout_marginTop="8dp"
    app:layout_constraintTop_toBottomOf="@+id/celsius"
    app:layout_constraintVertical_bias="0.0"/>

<TextView
    android:id="@+id/cityID"

    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginTop="4dp"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="16sp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.502"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/skyForecast"
    app:layout_constraintVertical_bias="0.005"
    tools:text="Redmond, Washington"
    android:layout_marginStart="8dp"
    android:layout_marginEnd="8dp"/>

<TextView
    android:id="@+id/currentTime"

    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginEnd="8dp"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="4dp"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="16sp"
    android:textStyle="bold"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.0"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/skyForecast"
    app:layout_constraintVertical_bias="0.554"
    tools:text="Monday, 10:30 am"/>

<TextView
    android:id="@+id/sunrise"

    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginEnd="8dp"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="4dp"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="18sp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.057"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/skyForecast"
    app:layout_constraintVertical_bias="0.854"
    tools:text="6:30 am"/>

<TextView
    android:id="@+id/windSpeed"

    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="18sp"
    app:layout_constraintVertical_bias="0.856"
    tools:text="10 m/s"
    app:layout_constraintTop_toTopOf="@+id/sunrise"
    tools:layout_editor_absoluteX="159dp"/>

<TextView
    android:id="@+id/randomID"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="18sp"
    tools:text="10 m/s"
    android:layout_marginTop="8dp"
    app:layout_constraintTop_toBottomOf="@+id/currentTime"
    app:layout_constraintBottom_toBottomOf="parent"
    android:layout_marginBottom="8dp"
    android:layout_marginRight="8dp"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintLeft_toRightOf="@+id/windSpeed"
    android:layout_marginLeft="8dp"
    app:layout_constraintHorizontal_bias="0.284"
    app:layout_constraintVertical_bias="0.649"/>

<TextView
    android:id="@+id/sunset"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginEnd="8dp"
    android:layout_marginLeft="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginStart="8dp"
    android:textAlignment="center"
    android:textColor="@color/white"
    android:textSize="18sp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.059"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/sunrise"
    app:layout_constraintVertical_bias="0.0"
    tools:text="7:30 pm"/>

<ProgressBar
    android:id="@+id/loadingLocation"
    style="?android:attr/progressBarStyle"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/settingsToolbar"
    app:layout_constraintVertical_bias="0.438"
    tools:visibility="visible"
    android:layout_marginLeft="8dp"
    app:layout_constraintLeft_toLeftOf="parent"
    android:layout_marginRight="8dp"
    app:layout_constraintRight_toRightOf="parent"
    android:layout_marginStart="8dp"
    android:layout_marginEnd="8dp"/>

<View
    android:id="@+id/view"
    android:layout_width="wrap_content"
    android:layout_height="1dp"
    android:layout_marginBottom="8dp"
    android:background="@color/colorPrimaryDark"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintHorizontal_bias="0.0"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/settingsToolbar"
    app:layout_constraintVertical_bias="0.0"/>

<ImageView
    android:id="@+id/imageView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginRight="8dp"
    app:layout_constraintRight_toRightOf="parent"
    app:srcCompat="@drawable/ic_wb_sunny_black_24dp"
    android:layout_marginLeft="8dp"
    app:layout_constraintLeft_toLeftOf="parent"
    android:layout_marginTop="8dp"
    app:layout_constraintTop_toBottomOf="@+id/currentTime"
    app:layout_constraintBottom_toBottomOf="parent"
    android:layout_marginBottom="8dp"
    app:layout_constraintHorizontal_bias="0.107"
    app:layout_constraintVertical_bias="0.397"
    android:layout_marginStart="8dp"
    android:layout_marginEnd="8dp"/>

<ImageView
    android:id="@+id/imageView2"
    android:layout_width="28dp"
    android:layout_height="28dp"
    android:layout_marginBottom="8dp"
    android:layout_marginTop="8dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/currentTime"
    app:layout_constraintVertical_bias="0.375"
    app:srcCompat="@drawable/wind_512"
    tools:layout_editor_absoluteX="173dp"/>

我尝试重建项目，取消应用程序，清理项目，构建APK，并且对我做错了很困惑。

Answer 1

感谢米哈伊尔，我发现了这个问题。事实证明，我有一个v23 version我的activity_main，使其可以在其他版本的android上运行，并使其成为错误的activity_main。