android - 从文件选择器中选择文件后返回主活动的活动

Question

就我而言，我打开文件选择器并选择一个文本文件以将数据导入数据库。现在我正在测试计数线。我得到了确切的行号，但问题是在选择文件并计算行数后，我的应用程序会自动返回主页。并且警报对话框也被关闭。我不知道发生了什么。这是我当前的代码。

    class Admin : AppCompatActivity() {

        internal lateinit var lbl: TextView
        internal lateinit var db: DataBaseHelper
        internal lateinit var btnimport: ImageView
        val requestcode=1
        internal lateinit var scan: Button


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

            val btn_pw = findViewById<Button>(R.id.btn_pwd)
            val btn_location = findViewById<Button>(R.id.btn_location)
            val btn_import = findViewById<Button>(R.id.btn_import)
            val btn_export = findViewById<Button>(R.id.btn_export)

            btn_pw.setOnClickListener{
                dialogLogin()
            }

            btn_location.setOnClickListener {
                val intent = Intent(this,Search::class.java)
                startActivity(intent)
            }

            btn_import.setOnClickListener {
                importDialog(R.style.DialogSlide,this)
            }


        }

        private fun dialogLogin(){
            val builder = AlertDialog.Builder(this)
            val inflater = this.layoutInflater
            val view = inflater.inflate(R.layout.activity_password,null)
            builder.setView(view)
            val dialog: AlertDialog = builder.create()
            dialog.window?.attributes?.windowAnimations = R.style.DialogSlide
            dialog.setMessage("Please Fill The Branch Name")
            dialog.show()

            val brn_save =view.findViewById<Button>(R.id.btn_save)
            val edt_pw = view.findViewById<EditText>(R.id.edt_pw)

            brn_save.setOnClickListener{
                branch = edt_pw.text.toString()


                if(edt_pw.text == null){
                    Toast.makeText(this,"Please fill the branch",Toast.LENGTH_SHORT).show()
                }
                else{
                    password = edt_pw.text.toString()
                    dialog.dismiss()
                    setpwd(password.toString())
                    real_pwd = password.toString()
                }
            }
        }

        private fun setpwd( v:String) {
            var editor=getSharedPreferences("yo", MODE_PRIVATE).edit()
            editor.putString("val", v)
            editor.apply()

        }

        /*import text file to database*/
        private fun importDialog(type: Int,context: Context) {
            val builder=AlertDialog.Builder(this)
            val inflater=this.layoutInflater
            val view=inflater.inflate(R.layout.import__dialog, null)
            builder.setView(view)
            val dialog: AlertDialog=builder.create()
            dialog.window?.attributes?.windowAnimations=type
            dialog.setMessage(context.getString(R.string.open_master))
            lbl=EditText(this)
            lbl=view.findViewById(R.id.edit_master)
            lbl.text=noti.toString()
            dialog.show()
            dialog.setCancelable(false)

            db=DataBaseHelper(this)

            btnimport=view.findViewById(R.id.img_import)

            btnimport.setOnClickListener {
                val fileintent=Intent(Intent.ACTION_GET_CONTENT)
                fileintent.type="txt/csv"
                try {
                    startActivityForResult(fileintent, requestcode)
                    dialog.show()
                } catch (e: ActivityNotFoundException) {
                    lbl.text="No activity can handle picking a file. Showing alternatives."
                }
            }


        }

        @SuppressLint("MissingSuperCall")
        override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
            if (data == null)
                return
            if (requestCode==requestcode) {
                val intent=Intent(this, MainActivity::class.java)
                startActivity(intent)
                val filepath=data.data
                val cursor=contentResolver.openInputStream(android.net.Uri.parse(filepath.toString()))
                lbl.text=filepath.toString()
                master_path=filepath.toString()
                noti=cursor.toString()
                val db=this.openOrCreateDatabase("database.db", Context.MODE_PRIVATE, null)
                val tableName="Master"
                db.execSQL("delete from $tableName")
                val text =  StringBuilder()
                try {
                    println("gg")
                    if (resultCode == Activity.RESULT_OK) {
                        try {
                            val file=InputStreamReader(cursor)
                            var lineCount = 0
                            val buffer=BufferedReader(file)
                            buffer.readLine()
                            val contentValues=ContentValues()
                            db.beginTransaction()

                            while(true) {
                                val line=buffer.readLine()

                                if (line == null) break
                                lineCount++

                            }
                            println(lineCount.toString())
                            db.setTransactionSuccessful()
                            db.endTransaction()
                        } catch (e: IOException) {
                            if (db.inTransaction())
                                db.endTransaction()
                            val d=Dialog(this)
                            d.setTitle(e.message.toString() + "first")
                            d.show()
                        }

                    } else {
                        if (db.inTransaction())
                            db.endTransaction()
                        val d=Dialog(this)
                        d.setTitle("Only CSV files allowed")
                        d.show()
                    }
                } catch (ex: Exception) {
                    if (db.inTransaction())
                        db.endTransaction()

                    val d=Dialog(this)
                    d.setTitle(ex.message.toString() + "second")
                    d.show()
                }

            }

        }


    }

标签： androidkotlin

Answer 1

看起来你是故意去那里的

if (requestCode==requestcode) {
    val intent=Intent(this, MainActivity::class.java)
    startActivity(intent)
    ...
    ...