#얻는법 | Explore Tumblr posts and blogs

jacob-cs · 5 years ago

Text

android kotlin 개발 팁 정리 (wasent 개발시 정리)

alt + enter 자동완성

ctrl + space 자동완성 basic code completion

cotrol + r run app

alt x mark 클릭 모든 코드창 닫기

현재 year 가져오기 Calendar.getInstance().get(Calendar.YEAR)

UI를 위한 변수를 자동생성 해주기 위해 필요

import kotlinx.android.sythetic.main.activity_main.*

android toast message

Toast.makeText().show()

kotlin random integer

Random.nextInt()

android drawable

<item>

<shape>

<solid>

android ImageView

resource 로 부터 이미지 가져오기

ImageView.setImageResource()

android ListView

BaseAdapter , getItem, getCount, getItemId, getView

ListView.adapter = BaseAdapter를implement한obj

android view layout

context객체.getSystemService()

android LayoutInflator 객체 얻는법

layoutInflator객체.inflate(Context.LAYOUT_INFLATER_SERVICE)

android activity

다른 actvity로 이동

Intent, intent객체.putExtra(), startActivity()

android Bundle activity Intent

intent에서 bundle data가져오기

intent객체.extras 는 Bundle 객체를 return. bundle객체.getString(”키이름”)

android ListView change delete update adapter

adapter객체.notifyDataSetChanged()

kotlin inner class access property

inner modifier

https://stackoverflow.com/a/45418262/3151712

android image drawable mipmap

한번에 다양한 크기의 같은 이미지 생성 프로그램

final_android_resizer

android GridView

ListView와 제작방법이 거의 동일하다.BaseAdapter , getItem, getCount, getItemId, getView. 단 GridView에 numColumns, columnWidth, horizontalSpacing 속성을 추가로 설정해야 한다.

GridView.adapter = BaseAdapter를implement한obj

android internet permission http

<uses-permission android:name = “android.permission.INTERNET”/>

android kotlin thread background

AsyncTask<> , doInBackground, onProgressUpdate, onPreExecute, onPostExecute

kotlin try catch

try{

}catch (ex:Exception){

}

android kotlin url connection

Url(url스트링) 하면 url객체를 얻을 수 있다.

url객체.openConnection()하면 urlconnection객체를 얻을수있고 이를 HttpUrlConnection 객체나 HttpsUrlConnection객체로 타입전환할수 있다. HttpUrlConnection객체.connectTimeout() 을 통해 제한시간 설정가능

HttpUrlConnection.inputStream 을 통해 외부로부터 data를 받을수 있게 된다.

InputStream, InputStreamReader, BufferedReader 를 사용 한줄 한줄 읽어 온다.

android json

JSONObect(스트링) , getJSONObect() 또는 getJSONArray()를 통해 한단계씩 들어가서 데이터를 가져온다.

android drawable background

상태에 따른 스타일 바꾸기

android firebase authentication analytics

Udemy kotlin android 강좌

google firebase 사용방법 121 analytics ,122 authentication 매우 간단하고 이해하기 쉽다.

124 analytics

127 datastore database

130 3:00 addValueEventListener

android notification

NotificationCompat.builder()

setDefault() setSmallIcon() setContentTitle() setContentText() setNumber()

context.getSystemService(context.NOTIFICATION_SERVICE)

Udemy kotlin android 강좌 132

android notification channel

NotificationChannel()

android image 사용 external storage camera permission

ActivityCompat.checkSelfPermission()

requestPermissions()

onRequestPermissionsResult()

udemy 136 3:00

android image file 디바이스에 있는 image file 가져오기

intent intent.ACTION_PICK android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI startActivityForResult()

android image file content provider 사용자가 선택한 화일 가져오기

android filebase storage imageview에 있는 이미지를 압축해서 firebase storage에 올리기

FirebaseStorage FirebaseStorage객체.getRefenceFromUrl()

udemy 137

android google firebase authentication

FirebaseAuth createUserWithEmailAndPassword() addOnCompleteListener()

FirebaseUser

android picasso imageview image

udemy 140 9:00

android cloud messaging firebase

앱을 사용하는 다수의 사용자에게 message 보낼때사용. udemy 144

FirebaseMessaging.getInstance().subscribeToTopic()

manifest에 service추가 , meta-data 추가

Service class 작성 onMessageReceived()

android kotlin variable element

참고) kotlin에서는 findById()과정없이 바로 element id통해 접근가능하다.

아래와 같이 사용해도 된다.

위와 같이 activity 안에 요소를 위한 variable을 만들고 view type을 명시적으로 해준경우 아래와 같이 <Button>을 해줘도 되고 안해도 된다.

그러나 아래와 같이 activity 안 어느 함수안에서 variable이 정의된경우 photoGalleryButton처럼 명시해주어야 한다.

android kotlin clicklistener listener lambda button

android kotlin photo picture intent

android photo gallery pick intent

android kotlin element id variable

kotlin에서는 findById()과정없이 바로 element id통해 접근가능하다.

android kotlin inputStream url http read buffer BufferedReader InputStreamReader

참고) BuffredReader에 대하여 https://www.baeldung.com/java-buffered-reader

android kotlin Toolbar ActionBar

아래에서는 toolbar는 activity_main layout에 있는 toolbar 의 id 이다.

android kotlin network

network에 연결되었는지 확인하는 경우

android kotlin AlertDialog

android kotlin bitmap url http

android kotlin progress bar

android kotlin button drawable background

gradientdrawable을 xml이 아닌 코드상에서 만드는 방법

android kotlin dp float drawable

gradientdrawable을 xml이 아닌 코드상에서 만들때 코너를 둥글게 만드는 경우 dp 사이즈를 설정해 주는데 이때 필요한 dp 값을 구하는 방법이다.

kotlin inner class nested

https://stackoverflow.com/a/46730214/3151712

android kotlin listener anonymous class lambda sam

https://antonioleiva.com/lambdas-kotlin-android/

android kotlin listener anonymous class lambda sam

https://antonioleiva.com/listeners-several-functions-kotlin/

https://antonioleiva.com/lambdas-kotlin/

android kotlin draw onDraw

https://stackoverflow.com/questions/13640541/view-ondrawcanvas-c-versus-drawcanvas-c-in-android

android kotlin TextUtils isEmpty EditText가 비었는지 확인 축약형

https://stackoverflow.com/a/6290637/3151712

android kotlin bundle 만들기 축약형

https://medium.com/@programmerr47/creating-bundles-nicely-with-kotlin-1526fc173d01

옛날방법 https://stackoverflow.com/a/59957980/3151712

android kotlin invoke operator overload

https://stackoverflow.com/questions/45173677/invoke-operator-operator-overloading-in-kotlin

android studio json to kotlin plugin

json 내용을 보고 그에 맞는 kotlin classes를 자동으로 만들어 준다.

android studio - > preferences -> plugin -> json to kotlin 검색

kotlin reference member class ::

https://stackoverflow.com/a/51813211/3151712

kotlin by keyword delegate delegation

https://stackoverflow.com/a/57637851/3151712

kotlin elivis operator null safety

fun elvisSample(arg : String?) { val value = arg ?: "" }

//같은내용 fun elvisSample(arg : String?) { val value = if (arg != null) arg else "" }

android room annotation

https://medium.com/@tonyowen/room-entity-annotations-379150e1ca82

@Entity

data class Person()

@Entity(tableName = "people") data class Person()

@PrimaryKey(autoGenerate = true)

val id: Long

@ColumnInfo(name = "first_name") val firstName: String = ""

@Ignore

val bitmap: Bitmap

@Entity data class Person( @PrimaryKey(autoGenerate = true) val uid: Long, val firstName: String = "", val lastName: String = "", val email: String = "" ) @Entity(foreignKeys = arrayOf(ForeignKey(entity = Person::class, parentColumns = arrayOf("uid"), childColumns = arrayOf("ownerId"), onDelete = ForeignKey.CASCADE))) data class Pet( @PrimaryKey(autoGenerate = true) val id: Long, val ownerId: Long, val name: String )

http://androidsbs.blogspot.com/2013/11/androidnextfocusdown-set-next-focus-to.html

Defines the next view to give focus to when the next focus is FOCUS_Down.

phone number edittext mask

https://stackoverflow.com/a/34907607/3151712

screen orientation

android:screenOrientation="portrait"

https://stackoverflow.com/a/13526816/3151712

android soft keyboard

https://stackoverflow.com/a/5617130/3151712

android dependency androidx jetpack

https://developer.android.com/kotlin/ktx

android navigation jetpack

https://developer.android.com/guide/navigation/navigation-getting-started

android data binding jetpack

https://stackoverflow.com/a/34719627/3151712

The data binding implementation must be in the onCreateView method of the fragment

public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { MartianDataBinding binding = DataBindingUtil.inflate( inflater, R.layout.martian_data, container, false); View view = binding.getRoot(); //here data must be an instance of the class MarsDataProvider binding.setMarsdata(data); return view; }

android tablelayout table

https://youtu.be/x0X19LJJGjc

android tablelayout table

https://youtu.be/2q7R3Pt-NCw

android tag

https://stackoverflow.com/a/45841698/3151712

android edittext text settext

https://stackoverflow.com/a/45841698/3151712

android viewmodel share activity fragment

https://medium.com/mindorks/how-to-communicate-between-fragments-and-activity-using-viewmodel-ca733233a51c

android viewmodel by error unresolve problem

https://stackoverflow.com/a/49934785/3151712

https://stackoverflow.com/a/60830396/3151712

android snackbar snack

https://www.androidhive.info/2015/09/android-material-design-snackbar-example/

android switch get data value

https://stackoverflow.com/a/47894048/3151712

android seekbar seek value listener get

https://abhiandroid.com/ui/seekbar

android seekbar value

https://stackoverflow.com/a/19227945/3151712

kotlin elvis ?:

https://kotlinlang.org/docs/reference/null-safety.html#elvis-operator

android layout half screen

https://stackoverflow.com/a/26379458/3151712

android weight weightsum

https://stackoverflow.com/questions/7452741/what-is-androidweightsum-in-android-and-how-does-it-work

android auto size text autosize textview font

official docs

https://developer.android.com/guide/topics/ui/look-and-feel/autosizing-textview

android auto size text autosize textview font

youtube 6분 , 컨셉이해

https://youtu.be/Dk3fI58RkPs

android editable text to string convert

https://stackoverflow.com/a/2216395/3151712

Kotlin - Apply, Let, Run, With, Also - Higher Order Standard Functions

youtube 11분 매우 명확

https://youtu.be/-Lha9n8VJf0

android navigation dialogfragment fragment dialog alert alertdialog

https://stackoverflow.com/a/55256858/3151712

android dialog dialogfragment alertdialog

https://blog.mindorks.com/implementing-dialog-fragment-in-android

android dialog dialogfragment alertdialog

youtube 7분 매우 간단

https://www.youtube.com/watch?v=alV6wxrbULs&t=2s

android callback function firebase addOnCompleteListener

https://stackoverflow.com/a/51595202/3151712

android SharedPreferences 와 Preferences 차이

https://stackoverflow.com/a/23223316/3151712

android SharedPreferences Preferences

https://youtu.be/M15PEeHXM64

30분 분량

https://youtu.be/SfeRakSWWbk

16분분량.

android action bar tool bar actionbar

https://www.journaldev.com/9357/android-actionbar-example-tutorial

android action bar tool bar actionbar

https://www.journaldev.com/9357/android-actionbar-example-tutorial

kotlin multiple constructor

https://stackoverflow.com/a/56277144/3151712

kotlin this nested class

https://agrawalsuneet.github.io/blogs/qualified-this-in-kotlin/

context requiredcontext

https://stackoverflow.com/a/60402600/3151712

android alert dialog view

https://stackoverflow.com/a/55685054/3151712

https://stackoverflow.com/a/22655641/3151712

android currency textwatcher mask

https://stackoverflow.com/a/24621325/3151712

https://stackoverflow.com/a/5233488/3151712 -> max length와 함께쓰면 문제 있었음

kotlin string replace

https://stackoverflow.com/a/50946070/3151712

kotlin data class inherit extend

https://stackoverflow.com/a/55701197/3151712

android spinner entries array value

https://www.mysamplecode.com/2012/03/android-spinner-arrayadapter.html

android string charsequences character

https://stackoverflow.com/a/1049244/3151712

android spannable

This is the interface for text to which markup objects can be attached and detached. Not all Spannable classes have mutable text; see Editable for that.

https://developer.android.com/reference/android/text/Spannable

android spinner get value getselecteditem select

https://stackoverflow.com/a/7486969/3151712

kotlin vararg array<string> variadic parameter argument

https://discuss.kotlinlang.org/t/vararg-vs-array-parameter/4068

kotlin remove character string

https://stackoverflow.com/a/49344240/3151712

android firebase child email key name @ at

https://stackoverflow.com/a/43863803/3151712

android androidx prefereces

https://developer.android.com/reference/androidx/preference/Preference

android alert dialog preference sharedpreference button click

https://stackoverflow.com/a/49444754/3151712

kotlin if express inline

https://stackoverflow.com/a/16336507/3151712

kotlin ?.let null null safety elvis ?.

https://www.reddit.com/r/Kotlin/comments/8k1885/why_cant_the_else_part_of_let_take_a_block/

muthuraj57 answer is best

android resource string viewmodel

https://stackoverflow.com/a/51279662/3151712

android firebase realtime database child event ChildEventListener

https://firebase.google.com/docs/reference/android/com/google/firebase/database/ChildEventListener

android firebase realtime database iterate traverse child

https://stackoverflow.com/a/44935464/3151712

kotlin collection

https://www.geeksforgeeks.org/kotlin-collections/

android kotlin firebase data class constructor

https://stackoverflow.com/a/51134246/3151712

android jetpack livedata observe collection

https://stackoverflow.com/a/52075248/3151712

android firebase child event listener remove ChildEventListener

https://stackoverflow.com/questions/46140289/removing-childeventlistener

android longclicklistener long click listener return true OnLongClickListener

https://stackoverflow.com/a/13470431/3151712

android string resource getstring

https://stackoverflow.com/a/44901859/3151712

kotlin string format

https://stonesoupprogramming.com/2017/11/17/kotlin-string-formatting/

livedata initialization initial

livedata는 기본적으로 null을 가지고 있다.

예를 들어 아래에서 liveItems.value 는 null이다. 그러나 보통은 val example = liveItems 하고 example의 값을 확인해보는게 정상적인 접근 방법이며 이경우에도 기본 최초값은 null이다.

val liveItems : LiveData<MutableMap<String, Item>> get() = _liveItems

livedata access

livedata의 값을 알고 싶을 때는 livedata.value를 사용하지 말고 일단 다른 var에 할당하고 확인한다.

kotlin collection

데이터타입 MutableMap<String, Item>을 생성하는 경우 아래와 같이

val items = mutableMapOf<String,Item>()

var stars: MutableMap<String, Boolean> = HashMap() var stars = HashMap<String,Boolean>()

데이터타입 MutableList<String>을 생성하는 경우 아래와 같이

val items = mutableListOf<String>()

val list: MutableList<String> = ArrayList<String>()

아래는 immutable list가 된다.

val list: List<String> = ArrayList()

ref) https://stackoverflow.com/a/50893555/3151712

https://www.geeksforgeeks.org/kotlin-collections/

https://www.geeksforgeeks.org/kotlin-mutablemapof/

kotlin dictionary contain key map hashmap

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/-map/contains-key.html

kotlin collection map list convert

https://grokonez.com/kotlin/kotlin-tutorial-convert-kotlin-map-list

kotlin map add item

https://stackoverflow.com/a/42627451/3151712

firebase android getvlaue generic collection list map dictionary

https://firebase.google.com/docs/reference/android/com/google/firebase/database/GenericTypeIndicator

https://stackoverflow.com/a/52684990/3151712

setOnClickListener onClickListener와 onClick in xml을 하나의 view에 동시사용할수는 없었다.

data binding에서 다른 viewid이름.text 값을 @{()-> } 통해 외부로 전달하려했지만 실패했다. 그냥 view obj자체를 전달할수는 있었다.

setOnFocusChangeListener 를 사용해서 focus에 따른 UI변화를 구현하다 알수 없는 bug에 고생함. 문제는 android가 xml load시에 자동으로 focus를 지정하는 문제가 있었다.

https://stackoverflow.com/a/59072414/3151712 로 문제 해결

firebase exist child

https://stackoverflow.com/a/39676175/3151712

listadapter android recyclerview

https://stackoverflow.com/a/55602833/3151712

adapter viewholder bind create

bind는 매번 viewholder에 데이터를 연결할때 마다 호출되므로 부하가 많이 걸릴수 있다.

https://stackoverflow.com/a/39271313/3151712

android data binding view id

다른 view의 id를 통해 접근, 속성값이용할수 있다.

https://stackoverflow.com/a/38126859/3151712

android databinding error problem 해결 모음

https://stackoverflow.com/questions/35126670/android-data-binding-error-cannot-find-symbol-class

android tag view

https://stackoverflow.com/a/5291891/3151712

kotlin NumberFormatter sign

https://stackoverflow.com/a/49907824/3151712

kotlin decimal zero point format

https://stackoverflow.com/questions/3973763/format-double-to-2-decimal-places-with-leading-0s

android auto focus remove

https://stackoverflow.com/a/59072414/3151712

android share activity fragment

https://medium.com/mindorks/how-to-communicate-between-fragments-and-activity-using-viewmodel-ca733233a51c

android gridlayoutmanager manager grid recyclerview

https://abhiandroid.com/materialdesign/recyclerview-gridview.html

android radio button check default

https://stackoverflow.com/questions/9175635/how-to-set-radio-button-checked-as-default-in-radiogroup

android radio button group check change

https://stackoverflow.com/questions/6780981/android-radiogroup-how-to-configure-the-event-listener

android radio button onclicklistener ontouchlistener

https://stackoverflow.com/questions/15836789/android-radio-button-uncheck

android onCheckedChanged radio button group

https://stackoverflow.com/questions/39427178/how-to-bind-method-on-radiogroup-on-checkchanged-event-with-data-binding

Android MVVM — Do’s and Don’ts tip head up

https://android.jlelse.eu/mvvm-dos-and-don-ts-5950d6f347d4

kotlin mat list convert

https://www.programiz.com/kotlin-programming/examples/convert-map-list

kotlin currency string mask format

https://kodejava.org/how-do-i-format-a-number-as-currency-string/

android edittext currency string mask format

https://stackoverflow.com/questions/5107901/better-way-to-format-currency-input-edittext/24621325#24621325

kotlin delegation property interface by

https://youtu.be/zfiohSIZtbo

https://youtu.be/JolUNygXu3s

https://kotlinlang.org/docs/reference/delegated-properties.html

android alert dialog alertdialog size window

https://stackoverflow.com/questions/18473989/custom-alertdialog-size-is-too-small

firebase child exist check children

https://stackoverflow.com/a/39676175/3151712

android radio button radiobutton data binding

https://stackoverflow.com/questions/49194398/how-to-use-two-way-data-binding-with-radio-button-in-android

android shared preference arraylist custom object class

https://stackoverflow.com/questions/14981233/android-arraylist-of-custom-objects-save-to-sharedpreferences-serializable

android hex decimal color string

https://stackoverflow.com/questions/5248583/how-to-get-a-color-from-hexadecimal-color-string

android color background programmatically

https://stackoverflow.com/a/41451718/3151712

android toggle button check change listener

https://stackoverflow.com/a/27911988/3151712

android data binding check switch change

https://stackoverflow.com/a/37288929/3151712

android leading zero decimal format number

https://stackoverflow.com/a/3973886/3151712

android alertdiaolog alert dialog

https://stackoverflow.com/a/54072166/3151712

android radio button group check change listener

https://stackoverflow.com/a/26618592/3151712

android bluetooth print blue tooth

https://stackoverflow.com/questions/9838822/android-bluetooth-printing

android textview scroll scrollable

https://stackoverflow.com/questions/1748977/making-textview-scrollable-on-android

android firebase transaction

https://stackoverflow.com/a/28915836/3151712

https://firebase.google.com/docs/database/android/read-and-write#save_data_as_transactions

firebase transaction twice call

https://stackoverflow.com/a/27177480/3151712

android datepicker picker calendar

https://stackoverflow.com/a/27177480/3151712

android datepicker date diable past

https://stackoverflow.com/a/23762355/3151712

android button click programmatically

https://stackoverflow.com/a/23762355/3151712

android date am pm calendar

Calendar c = Calendar.getInstance(); int seconds = c.get(Calendar.SECOND); int minutes = c.get(Calendar.MINUTE); int hours = c.get(Calendar.HOUR); int years = c.get(Calendar.YEAR); int months = 1 + c.get(Calendar.MONTH); int days = c.get(Calendar.DAY_OF_MONTH); int AM_orPM = c.get(Calendar.AM_PM);

android date format string simpledateformat

https://stackoverflow.com/a/38220579/3151712

android string builder

https://stackoverflow.com/a/8167156/3151712

android start activity

https://developer.android.com/training/basics/firstapp/starting-activity#BuildIntent

firebase sql like query search match

https://stackoverflow.com/a/61515511/3151712

kotlin check string number

https://www.programiz.com/kotlin-programming/examples/check-string-numeric#:~:text=To%20check%20if%20string%20contains,Else%2C%20it's%20a%20number.

firebase queyy filter retrieve

https://firebase.google.com/docs/database/android/lists-of-data#filtering_data

kotlin initialization init mutable map

val items = mutableMapOf("Box" to 12, "Books" to 18, "Table" to 13)

kotlin split string

val parts = str.split(delimiter)

firebase limit

https://stackoverflow.com/a/45324335/3151712

android paging library pagination recycler view

https://developer.android.com/topic/libraries/architecture/paging

https://www.zoftino.com/pagination-in-android-using-paging-library

https://proandroiddev.com/8-steps-to-implement-paging-library-in-android-d02500f7fffe

https://developer.android.com/reference/androidx/paging/PageKeyedDataSource

kotlin timestamp

https://stackoverflow.com/a/6993420/3151712

https://stackoverflow.com/a/6993393/3151712

android color background

https://stackoverflow.com/a/18033320/3151712

android programmatically navigation start activity

https://stackoverflow.com/a/53922244/3151712

https://stackoverflow.com/a/54613997/3151712

android pass serializable parcelable bundle argument

https://stackoverflow.com/a/59881330/3151712

kotlin convert array arraylist

https://www.programiz.com/kotlin-programming/examples/convert-list-array

kotlin mutable list initialization

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/mutable-list-of.html

mutableListOf(1, 2, 3)

android child get recyclerview viewholder view

https://stackoverflow.com/a/35603710/3151712

https://stackoverflow.com/a/38745107/3151712

kotlin for integer int

https://kotlinlang.org/docs/tutorials/kotlin-for-py/loops.html

for (x in 0 until 10)

kotlin hashmap merge combine add

https://stackoverflow.com/a/4299742/3151712

android activity clear remove stack history

https://stackoverflow.com/a/57079661/3151712

https://stackoverflow.com/questions/3473168/clear-the-entire-history-stack-and-start-a-new-activity-on-android

android encryption sharedpreferences shared preference

https://developer.android.com/reference/kotlin/androidx/security/crypto/EncryptedSharedPreferences.html

android androix version api

api 28

android encryption sharedpreferences shared preference encrypted

https://proandroiddev.com/encrypted-preferences-in-android-af57a89af7c8

https://medium.com/@Naibeck/android-security-encryptedsharedpreferences-ea239e717e5f

https://garageprojects.tech/encryptedsharedpreferences-example/

android email mask validation format

https://stackoverflow.com/a/44260895/3151712

android password validation special character capictal

https://stackoverflow.com/a/36574313/3151712

위의 것은 특수문자 하나 소문자 하나 대문자 하나를 최소기준으로 요구하는 코드이다.

android edit edittext focus listener

https://stackoverflow.com/a/10627231/3151712

android edit edittext focus listener data binding

https://stackoverflow.com/a/62015360/3151712

firebase email key

https://stackoverflow.com/a/50518018/3151712

android programmatically keyboard edittext edit text focus

https://stackoverflow.com/questions/8991522/how-can-i-set-the-focus-and-display-the-keyboard-on-my-edittext-programmatical

android required edittext edit

https://stackoverflow.com/a/53994791/3151712

android shared preference not allow double sharedpreferences

https://stackoverflow.com/questions/16319237/cant-put-double-sharedpreferences

android action bar tool bar

https://www.vogella.com/tutorials/AndroidActionBar/article.html

android finish end activity

finish()

android OnLongClickListener return

https://stackoverflow.com/a/49712696/3151712

android Refresh Fragment from other activity when Dialog fragment is dismissed

https://stackoverflow.com/questions/42868007/refresh-fragment-from-other-activity-when-dialog-fragment-is-dismissed

https://stackoverflow.com/a/9853895/3151712

android get key by value

https://stackoverflow.com/questions/12713321/can-i-get-the-key-from-sharedpreferences-if-a-know-the-associated-value

android programmatically keyboard soft hidden

https://stackoverflow.com/a/47826869/3151712

https://developer.android.com/reference/android/view/inputmethod/InputMethodManager.html#HIDE_NOT_ALWAYS

https://stackoverflow.com/q/10508363

android color primary primary dark accent

https://stackoverflow.com/a/47826869/3151712

android portrait

https://stackoverflow.com/a/3723830/3151712

android imeoption ime

https://stackoverflow.com/a/59758037/3151712

android cardview background card

https://stackoverflow.com/a/59758037/3151712

android dialog dialogfragment size window

https://stackoverflow.com/a/24213921/3151712

android recyclerview recycler scroll

https://stackoverflow.com/a/47260842/3151712

android sharedpreferences shared remove

https://stackoverflow.com/a/45620778/3151712

android focus programmatically edittext

https://stackoverflow.com/a/8991563/3151712

android data binding lifecycle lifecycle owner

https://stackoverflow.com/a/54542260/3151712

android negative button click date picker

https://stackoverflow.com/a/4981308/3151712

android toast custom

https://stackoverflow.com/a/31175631/3151712

android next focus edittext tab

https://developer.android.com/training/keyboard-input/navigation#Tab

firebase between startat endat

https://stackoverflow.com/a/29778220/3151712

kotlin sort collection reverse

https://stackoverflow.com/a/29778220/3151712

https://gold.gitbook.io/kotlin/collections/ordering-operations/sortedbydescending

android getcolor deprecated color backgound

https://stackoverflow.com/a/32202256/3151712

android kotlin singleton

https://antonioleiva.com/objects-kotlin/

kotlin calendar add month year day

https://www.tutorialspoint.com/add-months-to-current-date-using-calendar-add-method-in-java

android navigation component back go back findNavController navigateUp

https://stackoverflow.com/a/55174563/3151712

android spinner

https://www.geeksforgeeks.org/spinner-in-kotlin/

kotlin copy collection

https://stackoverflow.com/a/49053542/3151712

kotlin copy value list collection clone

https://stackoverflow.com/a/49053542/3151712

list.filter { true }

list.toList()

list.toMutableList()

kotlin pass value reference copy

https://stackoverflow.com/a/44516388/3151712

Every time I hear about the "pass-by-value" vs "pass-by-reference" Java debate I always think the same. The answer I give: "Java passes a copy (pass-by-value) of the reference (pass-by-reference)". So everyone is happy. I would say Kotlin does the same as it is JVM based language.

kotlin get property object list collection extension

https://medium.com/@hayi/kotlin-get-list-of-some-property-values-of-object-from-list-of-object-8da9419c2e77

inline fun <reified T, Y> MutableList<T>.listOfField(property: KMutableProperty1<T, Y?>):MutableList<Y> { val yy = ArrayList<Y>() this.forEach { t: T -> yy.add(property.get(t) as Y) } return yy }

kotlin collection property filter find

https://stackoverflow.com/a/51010611/3151712

val user: User? = myList.find { it.userId == id }

val user: User? = myList.last { it.userId == id }

android radio button toggle unselect uncheck check

https://stackoverflow.com/questions/43731189/how-to-uncheck-radiobutton-if-already-checked-in-radiogroup

https://stackoverflow.com/questions/15836789/android-radio-button-uncheck/22262182

kotlin break continue loop for

https://stackoverflow.com/questions/15836789/android-radio-button-uncheck/22262182

git restart renew start remove new

https://stackoverflow.com/a/31991358/3151712

kotlin data class copy value reference

https://kotlinlang.org/docs/reference/data-classes.html#copying

android soft keyboard InputMethodManager

https://developer.android.com/reference/android/view/inputmethod/InputMethodManager.

android soft keyboard programmatically hide

https://stackoverflow.com/a/54583382/3151712

android edittext capital first

https://stackoverflow.com/questions/4808705/first-letter-capitalization-for-edittext

android soft keyboard adjustpan adjustResize

https://stackoverflow.com/a/17410528/3151712

android navigation pass data start destination setGraph

https://developer.android.com/guide/navigation/navigation-pass-data#start

android navigation argument error exception illegalargumentexception currentDestination

https://stackoverflow.com/a/53737537/3151712.

android fragment change title action bar

https://stackoverflow.com/a/61323325/3151712

android studio kill restart adb start stop

https://stackoverflow.com/a/29826345/3151712

adb kill-server

adb start-server

android fragment pass result popup poputto previous

https://developer.android.com/guide/navigation/navigation-programmatic#returning_a_result

https://stackoverflow.com/a/60757744/3151712

android progress bar kotlin

https://www.tutorialkart.com/kotlin-android/android-indeterminate-progressbar-kotlin-example/

android spinner

https://www.geeksforgeeks.org/spinner-in-kotlin/

android spinner line space

https://stackoverflow.com/questions/15591768/add-more-space-between-items-in-android-spinner-without-custom-style

android kotlin programmatically text style

https://stackoverflow.com/a/52568928/3151712

android edittext remove focus

https://stackoverflow.com/a/6120141/3151712

android resource id get programmatically

https://stackoverflow.com/a/3476447/3151712

https://stackoverflow.com/a/15488321/3151712

android get package name

https://stackoverflow.com/questions/6589797/how-to-get-package-name-from-anywhere

android radio button two way data binding

https://stackoverflow.com/a/54262153/3151712

android animation navigation

https://stackoverflow.com/a/23081187/3151712

android radio button user programmatically check change

https://stackoverflow.com/a/63229190/3151712

android list filter

https://stackoverflow.com/a/44098722/3151712

android livedata radio button observe observer

livedata를 observe하는 경우 처음 activity나 fragment가 생성되서 코드를 읽어 내려가는 순간 최초로 한번 Observe 안의 코드가 한번 실행 된다. 그리고 observe하는 livedata가 변화되면 Observe 안의 코드가 또 실행된다.

radio button의 경우 사용자가 radio button 을 선택 클릭하면 OnCheckedChangeListener 가 두번 실행된다. 기존상황으로 한번 변화된 상황으로 한번실행된다.

kotlin byte bytearray java

ByteArray equals byte[] in Java Array<Byte> equals Byte[] in Java.

kotlin array

https://www.geeksforgeeks.org/kotlin-array/

android external library 3rd party jar

https://www.tutorialkart.com/kotlin-android/add-external-jar-to-library-in-android-studio/

kotlin byte

https://stackoverflow.com/a/44604635

android usb

https://developer.android.com/guide/topics/connectivity/usb/host#using-intents

kotlin java date datetime format day

https://stackoverflow.com/questions/5121976/is-there-a-date-format-to-display-the-day-of-the-week-in-java

android spinner

https://stackoverflow.com/questions/11072576/set-selected-item-of-spinner-programmatically

https://stackoverflow.com/questions/1947933/how-to-get-spinner-value

android recyclerview scroll

https://stackoverflow.com/a/48862743

android navigation google doc

https://developer.android.com/guide/navigation/navigation-getting-started

https://developer.android.com/guide/navigation/navigation-navigate

https://developer.android.com/reference/androidx/navigation/NavDestination

https://developer.android.com/guide/navigation/navigation-migrate

https://developer.android.com/guide/navigation/navigation-getting-started

android activity stack backstack navigation empty last isTaskRoot()

https://stackoverflow.com/a/44338195

android navigation component pass starting

https://stackoverflow.com/a/50457707

android edittext maxlength programmatically

https://stackoverflow.com/a/63722946

android cardview elevation animation

https://stackoverflow.com/questions/41110936/elevation-animation-on-click-on-cardview

https://kotlinlang.org/docs/reference/collection-filtering.html#filtering-by-predicate

filter collection

Filtering by predicate

The basic filtering function is filter(). When called with a predicate, filter() returns the collection elements that match it. For both List and Set, the resulting collection is a List, for Map it's a Map as well.

val numbers = listOf("one", "two", "three", "four")

val longerThan3 = numbers.filter { it.length > 3 }

println(longerThan3)

val numbersMap = mapOf("key1" to 1, "key2" to 2, "key3" to 3, "key11" to 11)

val filteredMap = numbersMap.filter { (key, value) -> key.endsWith("1") && value > 10}

println(filteredMap)

kotlin list group by

https://stackoverflow.com/a/47200815

https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/group-by.html

let

https://stackoverflow.com/a/52539259

a?.let { 첫번째 } ?: 두번째

a가 null이면 두번째실행하고 null이 아니면 첫번째실행

#android #tip #tips #팁 #kotlin #android studio

0 notes