\uc774 \uac15\uc88c\uc5d0\uc11c\ub294 \ucf54\ud2c0\ub9b0\uc744 \uc0ac\uc6a9\ud558\uc5ec \uc548\ub4dc\ub85c\uc774\ub4dc \uc571 \uac1c\ubc1c \uc2dc \uc561\ud2f0\ube44\ud2f0\ub97c \uc81c\uc5b4\ud558\ub294 \ubc29\ubc95\uc5d0 \ub300\ud574 \uae4a\uc774 \uc788\ub294 \uc124\uba85\uacfc \uc2e4\uc2b5 \uc608\uc81c\ub97c \uc81c\uacf5\ud569\ub2c8\ub2e4.<\/p>\n<\/header>\n \uc561\ud2f0\ube44\ud2f0\ub294 \uc548\ub4dc\ub85c\uc774\ub4dc \uc571\uc758 UI\ub97c \uad6c\uc131\ud558\ub294 \uae30\ubcf8\uc801\uc778 \ucef4\ud3ec\ub10c\ud2b8\uc785\ub2c8\ub2e4. \uac01 \uc561\ud2f0\ube44\ud2f0\ub294 \uc0ac\uc6a9\uc790\uc640 \uc0c1\ud638\uc791\uc6a9\ud558\ub294 \ub2e8\uc77c \ud654\uba74\uc744 \ub098\ud0c0\ub0b4\uba70, \uc5ec\ub7ec \uc561\ud2f0\ube44\ud2f0\ub97c \uc0ac\uc6a9\ud558\uc5ec \uc571\uc758 \uae30\ub2a5\uc744 \uad6c\ud604\ud569\ub2c8\ub2e4.<\/p>\n \uc608\ub97c \ub4e4\uc5b4, \ub85c\uadf8\uc778 \ud654\uba74, \uba54\uc778 \ud654\uba74, \uc124\uc815 \ud654\uba74 \ub4f1\uc774 \uac01\uac01 \ub3c5\ub9bd\uc801\uc778 \uc561\ud2f0\ube44\ud2f0\ub85c \uad6c\uc131\ub420 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uac01 \uc561\ud2f0\ube44\ud2f0\ub294 \uc0dd\uba85\uc8fc\uae30(lifecycle)\ub97c \uac00\uc9c0\uba70, \uc774\ub294 \uc571\uc758 \uc0c1\ud0dc \ubcc0\ud654\ub97c \uad00\ub9ac\ud558\ub294 \ub370 \uc911\uc694\ud55c \uc5ed\ud560\uc744 \ud569\ub2c8\ub2e4.<\/p>\n<\/section>\n \uc561\ud2f0\ube44\ud2f0\uc758 \uc0dd\uba85\uc8fc\uae30\ub294 \ub2e4\uc74c\uacfc \uac19\uc740 \uc8fc\uc694 \uba54\uc11c\ub4dc\ub4e4\ub85c \uad6c\uc131\ub429\ub2c8\ub2e4:<\/p>\n \uc774 \uc0dd\uba85\uc8fc\uae30 \uba54\uc11c\ub4dc\ub4e4\uc744 \uc801\uc808\ud788 \ud65c\uc6a9\ud558\uba74, \uc571\uc758 \uc0c1\ud0dc\ub97c \ud6a8\uacfc\uc801\uc73c\ub85c \uad00\ub9ac\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n<\/section>\n \uc774\uc81c \uac04\ub2e8\ud55c \uc548\ub4dc\ub85c\uc774\ub4dc \uc571\uc744 \ub9cc\ub4e4\uc5b4 \ubcf4\uaca0\uc2b5\ub2c8\ub2e4. Kotlin\uc73c\ub85c \uae30\ubcf8 \uc561\ud2f0\ube44\ud2f0\ub97c \uc0dd\uc131\ud558\ub294 \ubc29\ubc95\uc744 \uc0b4\ud3b4\ubcf4\uaca0\uc2b5\ub2c8\ub2e4.<\/p>\n Android Studio\ub97c \uc5f4\uace0 \uc0c8\ub85c\uc6b4 \ud504\ub85c\uc81d\ud2b8\ub97c \uc0dd\uc131\ud569\ub2c8\ub2e4. \ud504\ub85c\uadf8\ub798\ubc0d \uc5b8\uc5b4\ub85c Kotlin<\/strong>\uc744 \uc120\ud0dd\ud558\uace0, \uae30\ubcf8 \ud15c\ud50c\ub9bf\uc778 Empty Activity<\/strong>\ub97c \uc120\ud0dd\ud569\ub2c8\ub2e4. \ud504\ub85c\uc81d\ud2b8 \uc774\ub984\uc740 HelloWorld<\/strong>\ub85c \uc124\uc815\ud558\uaca0\uc2b5\ub2c8\ub2e4.<\/p>\n \uc704\uc758 \ucf54\ub4dc\uc5d0\uc11c \uc6b0\ub9ac\ub294 MainActivity<\/strong> \ud074\ub798\uc2a4\ub97c \uc0dd\uc131\ud558\uace0, \ub2e4\uc591\ud55c \uc0dd\uba85\uc8fc\uae30 \uba54\uc11c\ub4dc\ub97c \uc624\ubc84\ub77c\uc774\ub4dc\ud558\uc5ec \uac01 \uc0c1\ud0dc\uc5d0\uc11c \uc218\ud589\ud560 \uc791\uc5c5\uc744 \uc815\uc758\ud588\uc2b5\ub2c8\ub2e4.<\/p>\n \uc774\uc81c UI\ub97c \uc815\uc758\ud558\uae30 \uc704\ud574 activity_main.xml<\/strong> \ud30c\uc77c\uc744 \uc218\uc815\ud574\ubcf4\uaca0\uc2b5\ub2c8\ub2e4.<\/p>\n \uc704\uc758 XML \ucf54\ub4dc\uc5d0\uc11c \uc6b0\ub9ac\ub294 TextView<\/strong>\ub97c \uc0ac\uc6a9\ud558\uc5ec “Hello World!”\ub77c\ub294 \ud14d\uc2a4\ud2b8\ub97c \ud654\uba74 \uc911\uc559\uc5d0 \ud45c\uc2dc\ud588\uc2b5\ub2c8\ub2e4.<\/p>\n<\/section>\n \uc548\ub4dc\ub85c\uc774\ub4dc \uc571\uc5d0\uc11c\ub294 \ubcf4\ud1b5 \uc5ec\ub7ec \uac1c\uc758 \uc561\ud2f0\ube44\ud2f0\ub97c \uc0ac\uc6a9\ud558\uc5ec \uc0ac\uc6a9\uc790 \uc778\ud130\ud398\uc774\uc2a4\ub97c \uad6c\uc131\ud558\ub294 \uacbd\uc6b0\uac00 \ub9ce\uc2b5\ub2c8\ub2e4. \uc774 \uc139\uc158\uc5d0\uc11c\ub294 \uc561\ud2f0\ube44\ud2f0 \uac04 \uc774\ub3d9\ud558\ub294 \ubc29\ubc95\uc744 \uc0b4\ud3b4\ubcf4\uaca0\uc2b5\ub2c8\ub2e4.<\/p>\n \uc0c8\ub85c\uc6b4 \uc561\ud2f0\ube44\ud2f0\ub97c \ucd94\uac00\ud558\uaca0\uc2b5\ub2c8\ub2e4. SecondActivity<\/strong>\ub77c\ub294 \uc774\ub984\uc758 \uc561\ud2f0\ube44\ud2f0\ub97c \uc0dd\uc131\ud558\uace0, \ub0b4\uc6a9\ubb3c\uc740 \ub2e4\uc74c\uacfc \uac19\uc774 \uc124\uc815\ud569\ub2c8\ub2e4.<\/p>\n \uadf8\uc5d0 \ub530\ub978 XML \ub808\uc774\uc544\uc6c3\uc778 activity_second.xml<\/strong> \ud30c\uc77c\ub3c4 \uc218\uc815\ud569\ub2c8\ub2e4.<\/p>\n \uc774\uc81c MainActivity<\/strong>\uc5d0\uc11c SecondActivity<\/strong>\ub85c \uc774\ub3d9\ud560 \uc218 \uc788\ub294 \ucf54\ub4dc\ub97c \ucd94\uac00\ud558\uaca0\uc2b5\ub2c8\ub2e4. \ubc84\ud2bc\uc744 \ub9cc\ub4e4\uace0 \ud074\ub9ad\ud588\uc744 \ub54c \uc0c8\ub85c\uc6b4 \uc561\ud2f0\ube44\ud2f0\ub85c \uc804\ud658\ub418\ub3c4\ub85d \uc124\uc815\ud569\ub2c8\ub2e4.<\/p>\n \ubc84\ud2bc\uc744 \ud074\ub9ad\ud558\uba74 SecondActivity<\/strong>\ub85c \uc804\ud658\ub429\ub2c8\ub2e4.<\/p>\n<\/section>\n \uc561\ud2f0\ube44\ud2f0 \uac04\uc5d0 \ub370\uc774\ud130\ub97c \uc804\ub2ec\ud558\ub294 \uac83\ub3c4 \uc911\uc694\ud55c \uae30\ub2a5 \uc911 \ud558\ub098\uc785\ub2c8\ub2e4. \uacb0\uacfc\ub97c \ubc18\ud658\ud558\ub294 \ubc29\ubc95\uc5d0 \ub300\ud574 \uc124\uba85\ud569\ub2c8\ub2e4.<\/p>\n \uba3c\uc800, SecondActivity<\/strong>\uc5d0\uc11c \uacb0\uacfc\ub97c \ubc18\ud658\ud558\ub3c4\ub85d \uc218\uc815\ud569\ub2c8\ub2e4.<\/p>\n \uc774\uc81c MainActivity<\/strong>\uc5d0\uc11c \uacb0\uacfc\ub97c \ubc1b\uc744 \uc218 \uc788\ub3c4\ub85d \uc218\uc815\ud569\ub2c8\ub2e4.<\/p>\n \uc774\uc81c MainActivity<\/strong>\ub294 SecondActivity<\/strong>\ub85c\ubd80\ud130 \uacb0\uacfc\ub97c \ubc1b\uc744 \uc218 \uc788\uc73c\uba70 \uc774\ub97c UI\uc5d0 \ubc18\uc601\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n<\/section>\n \uc548\ub4dc\ub85c\uc774\ub4dc\uc5d0\uc11c\ub294 \uc561\ud2f0\ube44\ud2f0\ub97c \uc2dc\uc791\ud560 \ub54c \uc778\ud150\ud2b8\uc758 \ud50c\ub798\uadf8\ub97c \uc124\uc815\ud558\uc5ec \uc561\ud2f0\ube44\ud2f0\uc758 \ub3d9\uc791 \ubc29\uc2dd\uc744 \uc81c\uc5b4\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n \uac00\uc7a5 \ub9ce\uc774 \uc0ac\uc6a9\ub418\ub294 \ud50c\ub798\uadf8 \uc911 \uc77c\ubd80\ub294 \ub2e4\uc74c\uacfc \uac19\uc2b5\ub2c8\ub2e4:<\/p>\n \uc704\uc758 \ucf54\ub4dc\uc5d0\uc11c FLAG_ACTIVITY_CLEAR_TOP<\/strong>\uc744 \uc0ac\uc6a9\ud558\uba74 SecondActivity<\/strong>\ub97c \uc2dc\uc791\ud560 \ub54c \uc2a4\ud0dd\uc5d0 \uc788\ub294 \uae30\uc874 \uc561\ud2f0\ube44\ud2f0\uac00 \uc81c\uac70\ub429\ub2c8\ub2e4.<\/p>\n<\/section>\n \uc561\ud2f0\ube44\ud2f0\uc5d0 \ub2e4\uc591\ud55c \ud14c\ub9c8\uc640 \uc2a4\ud0c0\uc77c\uc744 \uc801\uc6a9\ud558\uc5ec UI\ub97c \uc870\uc815\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc5ec\uae30\uc11c\ub294 \ucee4\uc2a4\ud140 \ud14c\ub9c8\ub97c \ub9cc\ub4e4\uc5b4 \uc801\uc6a9\ud558\ub294 \ubc29\ubc95\uc5d0 \ub300\ud574 \uc124\uba85\ud569\ub2c8\ub2e4.<\/p>\n res\/values\/styles.xml \ud30c\uc77c\uc744 \uc5f4\uace0 \uc0c8\ub85c\uc6b4 \ud14c\ub9c8\ub97c \ucd94\uac00\ud569\ub2c8\ub2e4.<\/p>\n AndroidManifest.xml \ud30c\uc77c\uc5d0\uc11c MainActivity<\/strong>\uc5d0 \uc0c8\ub85c\uc6b4 \ud14c\ub9c8\ub97c \uc801\uc6a9\ud569\ub2c8\ub2e4.<\/p>\n \uc704\uc758 \ucf54\ub4dc\uc5d0\uc11c CustomTheme<\/strong>\ub97c \uc124\uc815\ud558\uc5ec \uc561\ud2f0\ube44\ud2f0\uc5d0 \uc801\uc6a9\ud558\uc600\uc2b5\ub2c8\ub2e4.<\/p>\n<\/section>\n \uc561\ud2f0\ube44\ud2f0\ub97c \uc885\ub8cc\ud558\ub294 \ubc29\ubc95\uc5d0\ub294 \uc5ec\ub7ec \uac00\uc9c0\uac00 \uc788\uc2b5\ub2c8\ub2e4. \uae30\ubcf8\uc801\uc73c\ub85c finish()<\/strong> \uba54\uc11c\ub4dc\ub97c \ud638\ucd9c\ud558\uc5ec \ud604\uc7ac \uc561\ud2f0\ube44\ud2f0\ub97c \uc885\ub8cc\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4.<\/p>\n \uc0ac\uc6a9\uc790\uac00 \ub4a4\ub85c\uac00\uae30 \ubc84\ud2bc\uc744 \ub20c\ub800\uc744 \ub54c \uc561\ud2f0\ube44\ud2f0\uac00 \uc885\ub8cc\ub418\ub3c4\ub85d \uc790\ub3d9\uc73c\ub85c \ucc98\ub9ac\ub41c\ub2e4\ub294 \uc810\ub3c4 \uc720\uc758\ud574\uc57c \ud569\ub2c8\ub2e4.<\/p>\n \uc704\uc758 \ucf54\ub4dc\uc5d0\uc11c \ubc84\ud2bc\uc744 \ud074\ub9ad\ud558\uba74 \ud604\uc7ac \uc561\ud2f0\ube44\ud2f0\uac00 \uc885\ub8cc\ub429\ub2c8\ub2e4.<\/p>\n<\/section>\n1. \uc561\ud2f0\ube44\ud2f0(Activity)\ub780?<\/h2>\n
2. \uc561\ud2f0\ube44\ud2f0\uc758 \uc0dd\uba85\uc8fc\uae30<\/h2>\n
\n
3. \uae30\ubcf8 \uc561\ud2f0\ube44\ud2f0 \uc0dd\uc131\ud558\uae30<\/h2>\n
3.1 \ud504\ub85c\uc81d\ud2b8 \uc0dd\uc131\ud558\uae30<\/h3>\n
3.2 \uc561\ud2f0\ube44\ud2f0 \ucf54\ub4dc \uc791\uc131<\/h3>\n
\n package com.example.helloworld\n\n import android.os.Bundle\n import androidx.appcompat.app.AppCompatActivity\n\n class MainActivity : AppCompatActivity() {\n override fun onCreate(savedInstanceState: Bundle?) {\n super.onCreate(savedInstanceState)\n setContentView(R.layout.activity_main)\n }\n\n override fun onStart() {\n super.onStart()\n \/\/ \uc561\ud2f0\ube44\ud2f0\uac00 \uc2dc\uc791\ub420 \ub54c \uc218\ud589\ud560 \uc791\uc5c5\n }\n\n override fun onResume() {\n super.onResume()\n \/\/ \uc561\ud2f0\ube44\ud2f0\uac00 \ud3ec\uadf8\ub77c\uc6b4\ub4dc\uc5d0 \uc788\uc744 \ub54c \uc218\ud589\ud560 \uc791\uc5c5\n }\n\n override fun onPause() {\n super.onPause()\n \/\/ \uc561\ud2f0\ube44\ud2f0\uac00 \uc911\ub2e8\ub420 \ub54c \uc218\ud589\ud560 \uc791\uc5c5\n }\n\n override fun onStop() {\n super.onStop()\n \/\/ \uc561\ud2f0\ube44\ud2f0\uac00 \ub354 \uc774\uc0c1 \ubcf4\uc774\uc9c0 \uc54a\uc744 \ub54c \uc218\ud589\ud560 \uc791\uc5c5\n }\n\n override fun onDestroy() {\n super.onDestroy()\n \/\/ \uc561\ud2f0\ube44\ud2f0\uac00 \uc885\ub8cc\ub420 \ub54c \uc218\ud589\ud560 \uc791\uc5c5\n }\n }\n <\/code><\/pre>\n3.3 XML \ub808\uc774\uc544\uc6c3 \uc124\uc815<\/h3>\n
\n <?xml version=\"1.0\" encoding=\"utf-8\"?>\n <RelativeLayout xmlns:android=\"http:\/\/schemas.android.com\/apk\/res\/android\"\n android:layout_width=\"match_parent\"\n android:layout_height=\"match_parent\">\n\n <TextView\n android:id=\"@+id\/textView\"\n android:layout_width=\"wrap_content\"\n android:layout_height=\"wrap_content\"\n android:text=\"Hello World!\"\n android:layout_centerInParent=\"true\" \/>\n\n <\/RelativeLayout>\n <\/code><\/pre>\n4. \uc561\ud2f0\ube44\ud2f0 \uac04 \uc774\ub3d9<\/h2>\n
4.1 \uc0c8 \uc561\ud2f0\ube44\ud2f0 \uc0dd\uc131<\/h3>\n
\n package com.example.helloworld\n\n import android.os.Bundle\n import androidx.appcompat.app.AppCompatActivity\n\n class SecondActivity : AppCompatActivity() {\n override fun onCreate(savedInstanceState: Bundle?) {\n super.onCreate(savedInstanceState)\n setContentView(R.layout.activity_second)\n }\n }\n <\/code><\/pre>\n4.2 XML \ub808\uc774\uc544\uc6c3 \uc124\uc815<\/h3>\n
\n <?xml version=\"1.0\" encoding=\"utf-8\"?>\n <RelativeLayout xmlns:android=\"http:\/\/schemas.android.com\/apk\/res\/android\"\n android:layout_width=\"match_parent\"\n android:layout_height=\"match_parent\">\n\n <TextView\n android:layout_width=\"wrap_content\"\n android:layout_height=\"wrap_content\"\n android:text=\"This is the Second Activity\"\n android:layout_centerInParent=\"true\" \/>\n\n <\/RelativeLayout>\n <\/code><\/pre>\n4.3 \uc561\ud2f0\ube44\ud2f0 \uc804\ud658 \ucf54\ub4dc \ucd94\uac00<\/h3>\n
\n <Button\n android:id=\"@+id\/button\"\n android:layout_width=\"wrap_content\"\n android:layout_height=\"wrap_content\"\n android:text=\"Go to Second Activity\"\n android:layout_below=\"@id\/textView\"\n android:layout_centerHorizontal=\"true\"\/> \n <\/code><\/pre>\n\n \/\/ MainActivity \ucf54\ub4dc\uc758 onCreate \uba54\uc11c\ub4dc\uc5d0 \ucd94\uac00\n val button: Button = findViewById(R.id.button)\n button.setOnClickListener {\n val intent = Intent(this, SecondActivity::class.java)\n startActivity(intent)\n }\n <\/code><\/pre>\n5. \uc561\ud2f0\ube44\ud2f0 \uacb0\uacfc \uc804\ub2ec\ud558\uae30<\/h2>\n
5.1 \uacb0\uacfc\ub97c \ubc18\ud658\ubc1b\ub294 \uc561\ud2f0\ube44\ud2f0 \uc124\uc815<\/h3>\n
\n \/\/ SecondActivity \ucf54\ub4dc\n button.setOnClickListener {\n val resultIntent = Intent()\n resultIntent.putExtra(\"result\", \"Result from Second Activity\")\n setResult(RESULT_OK, resultIntent)\n finish()\n }\n <\/code><\/pre>\n5.2 \uacb0\uacfc\ub97c \ubc1b\ub294 \uc561\ud2f0\ube44\ud2f0 \uc124\uc815<\/h3>\n
\n \/\/ MainActivity \ucf54\ub4dc\uc5d0 \ucd94\uac00\n val startForResult = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->\n if (result.resultCode == Activity.RESULT_OK) {\n val data: Intent? = result.data\n val resultText = data?.getStringExtra(\"result\")\n \/\/ TextView\uc5d0 \uacb0\uacfc \uc124\uc815\n }\n }\n\n button.setOnClickListener {\n val intent = Intent(this, SecondActivity::class.java)\n startForResult.launch(intent)\n }\n <\/code><\/pre>\n6. \uc561\ud2f0\ube44\ud2f0\uc758 \ud50c\ub798\uadf8(flag) \uc124\uc815<\/h2>\n
\n
6.1 \ud50c\ub798\uadf8 \uc608\uc81c<\/h3>\n
\n val intent = Intent(this, SecondActivity::class.java)\n intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)\n startActivity(intent)\n <\/code><\/pre>\n7. \uc561\ud2f0\ube44\ud2f0 \ud14c\ub9c8 \ubc0f \uc2a4\ud0c0\uc77c \uc801\uc6a9\ud558\uae30<\/h2>\n
7.1 \ud14c\ub9c8 \uc124\uc815\ud558\uae30<\/h3>\n
\n <style name=\"CustomTheme\" parent=\"Theme.AppCompat.Light.NoActionBar\">\n <item name=\"colorPrimary\">#FF5722<\/item>\n <item name=\"colorPrimaryDark\">#E64A19<\/item>\n <item name=\"colorAccent\">#FFC107<\/item>\n <\/style>\n <\/code><\/pre>\n7.2 \ud14c\ub9c8 \uc801\uc6a9\ud558\uae30<\/h3>\n
\n <activity\n android:name=\".MainActivity\"\n android:theme=\"@style\/CustomTheme\">\n <\/activity>\n <\/code><\/pre>\n8. \uc561\ud2f0\ube44\ud2f0 \uc885\ub8cc<\/h2>\n
\n button.setOnClickListener {\n finish()\n }\n <\/code><\/pre>\n