CODEWITHSUNDEEP
androidkotlin
Arun
Arun

Reputation: 45

Initialisation of ImageView in Kotlin

I am trying to display the bitmap in an ImageView.

The following XML code is the ImageView.

<ImageView
        android:id="@+id/image"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_centerInParent="true" />

I lateinit the image view in MainActivity class as:

private lateinit var image: ImageView

I have perfect bitmap, there is no error in bitmap. The bitmap is passed from the a view kotlin class to the MainActivity.kt's "show_result" function. The following function is in MainActivity.kt

fun show_result(bm: Bitmap){
    image = findViewById(R.id.image)
    image.setImageBitmap(bm)
    }

Then, I got the following error, when I called the show_result function. Error:

E/InputEventReceiver: Exception dispatching input event.
E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
E/MessageQueue-JNI: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
        at android.content.ContextWrapper.getApplicationInfo(ContextWrapper.java:152)
        at android.view.ContextThemeWrapper.getTheme(ContextThemeWrapper.java:157)
        at android.content.Context.obtainStyledAttributes(Context.java:655)
        at androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:839)
        at androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:806)
        at androidx.appcompat.app.AppCompatDelegateImpl.findViewById(AppCompatDelegateImpl.java:630)
        at androidx.appcompat.app.AppCompatActivity.findViewById(AppCompatActivity.java:223)
        at com.app.symbolrecogniser.MainActivity.show_result(MainActivity.kt:75)
        at com.app.symbolrecogniser.CanV.saveBitmap(CanV.kt:424)
        at com.app.symbolrecogniser.CanV.touchUp(CanV.kt:196)
        at com.app.symbolrecogniser.CanV.onTouchEvent(CanV.kt:117)
        at android.view.View.dispatchTouchEvent(View.java:11776)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:448)
        at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1829)
        at android.app.Activity.dispatchTouchEvent(Activity.java:3307)
        at androidx.appcompat.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69)
        at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:410)
        at android.view.View.dispatchPointerEvent(View.java:12015)
        at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4795)
        at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4609)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4147)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4200)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4166)
        at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4293)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4174)
        at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4350)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4147)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4200)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4166)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4174)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4147)
        at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6661)
        at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6635)
        at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6596)
        at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6764)
        at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:186)
        at android.os.MessageQueue.nativePollOnce(Native Method)
        at android.os.Mess
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.app.symbolrecogniser, PID: 8853
    java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
        at android.content.ContextWrapper.getApplicationInfo(ContextWrapper.java:152)
        at android.view.ContextThemeWrapper.getTheme(ContextThemeWrapper.java:157)
        at android.content.Context.obtainStyledAttributes(Context.java:655)
        at androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:839)
        at androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:806)
        at androidx.appcompat.app.AppCompatDelegateImpl.findViewById(AppCompatDelegateImpl.java:630)
        at androidx.appcompat.app.AppCompatActivity.findViewById(AppCompatActivity.java:223)
        at com.app.symbolrecogniser.MainActivity.show_result(MainActivity.kt:75)
        at com.app.symbolrecogniser.CanV.saveBitmap(CanV.kt:424)
        at com.app.symbolrecogniser.CanV.touchUp(CanV.kt:196)
        at com.app.symbolrecogniser.CanV.onTouchEvent(CanV.kt:117)
        at android.view.View.dispatchTouchEvent(View.java:11776)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2968)
        at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2657)
        at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:448)
        at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1829)
        at android.app.Activity.dispatchTouchEvent(Activity.java:3307)
        at androidx.appcompat.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:69)
        at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:410)
        at android.view.View.dispatchPointerEvent(View.java:12015)
        at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4795)
        at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4609)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4147)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4200)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4166)
        at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4293)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4174)
        at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4350)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4147)
        at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4200)
        at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4166)
        at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4174)
        at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4147)
        at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6661)
        at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6635)
        at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6596)
        at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6764)
E/AndroidRuntime:     at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:186)
        at android.os.MessageQueue.nativePollOnce(Native Method)
        at android.os.MessageQueue.next(MessageQueue.java:325)
        at android.os.Looper.loop(Looper.java:142)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

MainActivity.kt

class MainActivity : AppCompatActivity() {

    private lateinit var image: ImageView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
    }

    fun show_result(bm: Bitmap){
        image = findViewById(R.id.image)
        image.setImageBitmap(bm)
    }

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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/canv_fix"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity"
    tools:ignore="ContentDescription">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme" />


    <ImageView
        android:id="@+id/image"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_centerInParent="true" />

    <TextView
        android:id="@+id/label"
        style="@style/TextAppearance.AppCompat.Headline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/image"
        android:layout_centerHorizontal="true"
        android:layout_margin="10dp" />

    <TextView
        android:id="@+id/probability"
        style="@style/TextAppearance.AppCompat.Body1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/label"
        android:layout_centerHorizontal="true" />
</LinearLayout>

Upvotes: 0

Views: 263

Answers (1)

Shawn
Shawn

Reputation: 1372

This line in the log typically means that you are referencing a view that the activity or fragment hasn't loaded, so it returns null.

E/MessageQueue-JNI: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
        at android.content.ContextWrapper.getApplicationInfo(ContextWrapper.java:152)

This line is narrows down where the problem is in the code.

at com.app.symbolrecogniser.MainActivity.show_result(MainActivity.kt:75)

The problem is the image = findViewById(...), this view isn't loaded in the activity that's calling it.

Upvotes: 1

Related Questions