Btukfyl

In my doInBackground I declare and Initialize db, I got an error which say type mismatch. What should I put instead of putting this?

var dbHelper: MyDBHelper? = null

dbHelper = MyDBHelper(this)

What should I put, There say Required: Context!

And this is my async task code, That Problem at dbHelper = MyDBHelper(this).

private class UpgradeDB(textView: TextView?) : AsyncTask<String, String, String>() {

        var innerTextView: TextView? = textView



        override fun onPreExecute() {

            innerTextView!!.visibility = View.VISIBLE

        }



        override fun doInBackground(vararg params: String): String? {

            val filename = "eBOSSInv_Upgrade.sql"

            val sdcard = Environment.getExternalStorageDirectory()

            val file = File(sdcard, filename)



            if (!file.exists()) isCancelled



            try {

                var dbHelper: MyDBHelper? = null



                dbHelper = MyDBHelper(this)



                dbHelper!!.writableDatabase.use { db ->

                    var intTotalLine = 0

                    var intLine = 1

                    BufferedReader(FileReader(file)).useLines { _ -> intTotalLine++ }

                    BufferedReader(FileReader(file)).use { r ->

                        r.lineSequence().forEach {

                            if (it.isNotEmpty()) {

                                db!!.execSQL(it)

                                publishProgress(String.format("Updating %s/%s records", intLine, intTotalLine))

                                intLine++

                            }

                        }

                    }

                }

            } catch (e: Exception) {



            }

            return null

        }



        override fun onProgressUpdate(vararg text: String) {

            innerTextView!!.text = text[0]

        }



        override fun onPostExecute(result: String?) {

            innerTextView!!.text = ""

        }



        override fun onCancelled() {



        }

    }

You need to pass context into Async Task.

Example:

llUpdate.setOnClickListener { 

       UpgradeDB(txtUpdate!!, getApplication()).execute("", "", "") 

}

Then in UpgradeDB, initialize the context.

private class UpgradeDB(textView: TextView?, context: Context) : AsyncTask<String, String, String>() {

        var innerTextView: TextView? = textView

        var mContext:Context? = context // initialize context

    }

And finally

dbHelper = MyDBHelper(mContext)

It depends where you try to create this object. Unless you do it in a class that extends Context (like Activity) it is not supposed to work. You can try such construct:

There are two ways you gan go:

The simpler way: Declare your AsyncTask as inner class inside tour activity and reference context using label. To declare class as inner you need to place it inside another class and add inner keyowrd:

class A {



    inner class B



}

Now you can reference context from inside your async task like that:

dbHelper = DbHelper([ActivityName]@this)

Nevertheless, this is easy way to cause a memory leak, you can read more here: Android AsyncTask memory leaks

The better way is to extract AsyncTask to another class and pass an application context to it, instead of Activity.