将 java 代码转换为 kotlin 后的 IllegalStateException

Question

将java代码转换为kotlin后，我得到了IllegalStateException.我用过kotlin extension.在java中，我的应用程序没有这样的问题，现在它随着具有相同IllegalStateException的每个活动而崩溃。我已经尝试清理，重建和使缓存失效并重新启动，但没有一个能够解决我的问题。这是我的活动课，

class SettingsActivity : BaseActivity() {
private val SHOW = "SHOW"
private val CLEAR = "CLEAR"
private var context: Context? = null
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_settings)
    context = this
    //at this line I am getting error
    versionInfo.text = BuildConfig.VERSION_NAME
    val cacheStr = "Clear " + clearCache(SHOW) + " MB"
    cache.text = cacheStr
}
private fun clearCache(ACTION: String): Long {
    return null
}
}

这是我的 xml 文件

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/background">
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="General"
        android:paddingStart="16dp"
        android:paddingTop="8dp"
        android:paddingBottom="4dp"
        android:textSize="16sp"
        android:textStyle="bold"
        android:textColor="@android:color/white"/>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Version"
            android:paddingStart="16dp"
            android:paddingTop="8dp"
            android:textSize="15sp"
            android:textColor="@android:color/white"/>
        <TextView
            android:id="@+id/versionInfo"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="1.1.1"
            android:paddingStart="16dp"
            android:paddingBottom="8dp"
            android:textSize="15sp"
            android:textColor="@android:color/white"/>
    </LinearLayout>
</LinearLayout>

这是我的堆栈跟踪

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.littleapps.wallpaper/com.littleapps.wallpaper.activity.SettingsActivity}: java.lang.IllegalStateException: versionInfo must not be null
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2779)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2857)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1590)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6499)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:442)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
 Caused by: java.lang.IllegalStateException: versionInfo must not be null
    at com.littleapps.wallpaper.activity.SettingsActivity.onCreate(SettingsActivity.kt:30)
    at android.app.Activity.performCreate(Activity.java:7044)
    at android.app.Activity.performCreate(Activity.java:7035)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2732)

这是我的清单文件

<?xml version="1.0" encoding="utf-8"?>

<application
    android:name=".application.MyApplication"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity
        android:name=".activity.MainActivity"
        android:label="@string/app_name"
        android:windowSoftInputMode="stateHidden" />
    <activity
        android:name=".activity.SplashActivity"
        android:configChanges="orientation|keyboardHidden|screenSize"
        android:label="@string/title_activity_splash"
        android:theme="@style/FullscreenTheme" />
    <activity android:name=".activity.SettingsActivity" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <!-- <__________________FIREBASE MESSAGING SERVICES______________________> -->
    <service
        android:name=".services.MyFirebaseInstanceIdService"
        android:permission="android.permission.BIND_JOB_SERVICE">
        <intent-filter>
            <action android:name="com.google.firebase.INSTANCE_ID_EVENT" />
        </intent-filter>
    </service>
    <service
        android:name=".services.MyFirebaseMessagingService"
        android:permission="android.permission.BIND_JOB_SERVICE">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT" />
        </intent-filter>
    </service>
</application>

Answer 1

确保使用正确的布局和/或文本视图。也许您在不同的布局中具有相同的id，这会导致问题。

您可以在引用上使用 ctrl + left mouse button click 组合来检查这是否是您要更新的正确控件。