android - Capturing an image through camera and storing it in internal storage

Question

https://developer.android.com/training/camera/photobasics I tried to follow this link for capturing an image through camera and storing it in the internal storage of mobile. But whenever I click on capture button, the application gets crash. I have changed manifest and made an xml file for path of file too. I am new to android development so please try to explain step by step if possible. I am attaching the code here:

class MainActivity : AppCompatActivity() {
    var REQUEST_IMAGE_CAPTURE = 1
    lateinit var image: ImageView
    lateinit var currentPhotoPath: String
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        image = findViewById(R.id.image)
    }

    fun onClickingCapture(view: View) {
        //createImageFile()

        dispatchTakePictureIntent(this)

    //    galleryAddPic()
    }


//    private fun dispatchTakePictureIntent() {
//
//        val takePictureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
//        try {
//            startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE)
//        } catch (e: ActivityNotFoundException) {
//            // display error state to the user
//        }
//    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
            val imageBitmap = data?.extras?.get("data") as Bitmap
            image.setImageBitmap(imageBitmap)
            //saveImage(this,imageBitmap,"Try","jpeg")
        }
    }

    private fun dispatchTakePictureIntent(mainActivity: MainActivity) {
        Intent(MediaStore.ACTION_IMAGE_CAPTURE).also { takePictureIntent ->
            // Ensure that there's a camera activity to handle the intent
            takePictureIntent.resolveActivity(mainActivity.packageManager)?.also {
                // Create the File where the photo should go
                val photoFile: File? = try {
                    createImageFile()
                } catch (ex: IOException) {

                    null
                }
                // Continue only if the File was successfully created
                photoFile?.also {
                    val photoURI: Uri = FileProvider.getUriForFile(
                            this,
                            "com.example.android.fileprovider",
                            it
                    )
                    takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI)
                    startActivityForResult(takePictureIntent, mainActivity.REQUEST_IMAGE_CAPTURE)
                }
            }
        }
    }


    @Throws(IOException::class)
    fun createImageFile(): File {
        // Create an image file name
        val timeStamp: String = SimpleDateFormat("yyyyMMdd_HHmmss").format(Date())
        val storageDir: File? = getExternalFilesDir(Environment.DIRECTORY_PICTURES)
        return File.createTempFile(
                "JPEG_${timeStamp}_",
                ".jpg",
                storageDir
        ).apply {
            // Save a file: path for use with ACTION_VIEW intents
            currentPhotoPath = absolutePath
        }
    }
//    private fun galleryAddPic() {
//        Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE).also { mediaScanIntent ->
//            val f = File(currentPhotoPath)
//            mediaScanIntent.data = Uri.fromFile(f)
//            sendBroadcast(mediaScanIntent)
//        }
//    }

    fun saveImage(context: Context, bitmap: Bitmap, name: String, extension: String) {
        var name = name
        name = "$name.$extension"
        val fileOutputStream: FileOutputStream
        try {
            fileOutputStream = context.openFileOutput(name, Context.MODE_PRIVATE)
            bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fileOutputStream)
            fileOutputStream.close()
        } catch (e: Exception) {
            e.printStackTrace()
        }
    }

}

This is manifest:

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

<uses-feature android:name="android.hardware.camera"
    android:required="true" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/Theme.JpegToPdf">

    <provider
        android:name="androidx.core.content.FileProvider"
        android:authorities="com.example.android.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths"/>
    </provider>

    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

This is file_path.xml

    <?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-files-path name="my_images" path="Android/data/com.example.jpegtopdf/files/Pictures" />
</paths>

This is the exception shown in my logcat when I capture the image and expected to go back to the main activity.

Process: com.example.jpegtopdf, PID: 25424
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=null} to activity {com.example.jpegtopdf/com.example.jpegtopdf.MainActivity}: java.lang.NullPointerException: null cannot be cast to non-null type android.graphics.Bitmap
    at android.app.ActivityThread.deliverResults(ActivityThread.java:5202)
    at android.app.ActivityThread.handleSendResult(ActivityThread.java:5243)
    at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:51)
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:140)
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:100)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2239)
    at android.os.Handler.dispatchMessage(Handler.java:107)
    at android.os.Looper.loop(Looper.java:227)
    at android.app.ActivityThread.main(ActivityThread.java:7822)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1026)
 Caused by: java.lang.NullPointerException: null cannot be cast to non-null type android.graphics.Bitmap
    at com.example.jpegtopdf.MainActivity.onActivityResult(MainActivity.kt:53)
    at android.app.Activity.dispatchActivityResult(Activity.java:8303)
    at android.app.ActivityThread.deliverResults(ActivityThread.java:5195)
    at android.app.ActivityThread.handleSendResult(ActivityThread.java:5243)?
    at android.app.servertransaction.ActivityResultItem.execute(ActivityResultItem.java:51)?
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:140)?
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:100)?
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2239)?
    at android.os.Handler.dispatchMessage(Handler.java:107)?
    at android.os.Looper.loop(Looper.java:227)?
    at android.app.ActivityThread.main(ActivityThread.java:7822)?
    at java.lang.reflect.Method.invoke(Native Method)?
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)?
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1026)

Answer 1

等待大神答复