開発 4 年目のアプリへの Kotlin 導入

2017/07/12 Kotlin 開発 Tech Talks

Transcript

1. Ꟛ涪䎃湡ך،فٔפך,PUMJO㼪Ⰵ
   

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2. 㹧♴畆㣐龤
   $IBU8PSL吳䒭⠓爡
   ،فٔ؛٦ءّٝꟚ涪鿇ث٦ئ٦ت٦
   !SZVHPP@
   

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3. $IBU8PSLחאְג
   

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4. $IBU8PSL
   㕂欵ךؽآطأثٍحز؟٦ؽأ
   䎃剢ַ׵䲿⣘Ꟛ㨣
   㼪Ⰵ爡侧 爡
   䎃剢劣傈儗挿
   䎃劣ח4DBMB׾㼪Ⰵ
   1)1׮⢘欽׃גְֹתׅ
   

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5. ؒٝآص،⹫꧊⚥
   J04"OESPJEؒٝآص،⹫꧊⚥
   匌❨ؔؿ؍أ㣐ꢻؔؿ؍أ
   匌❨ؔؿ؍أכ剢ח匌❨ةٙ٦׉לח獳鯄
   IUUQDPSQDIBUXPSLDPNKBSFDSVJUFOHJOFFS
   

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6. $IBU8PSLךٌغ؎ٕ،فٔ
   剑ⴱכ5JUBOJVN醡
   +BWB4DSJQUדط؎ذ؍ـ6*׾䭯א،فָٔ⡲׸׷
   3FBDU/BUJWF׫׋ְזװאך饥׶
   "OESPJE晛
   䎃剢ַ׵ط؎ذ؍ـ⻉
   J04晛
   䎃剢ַ׵ط؎ذ؍ـ⻉
   

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7. 䎃剢
   ➂ד"OESPJEط؎ذ؍ـ晛ךꟚ涪׾Ꟛ㨣
   䎃剢
   ,PUMJO⹈䓼⠓ח겣׾⳿ׅ
   䎃剢
   "OESPJEط؎ذ؍ـ晛׾ٔٔ٦أ
   䎃
   せ̔せ⡤ⵖח
   䎃剢
   ,PUMJO醡ך傈㜠،فٔ׾爡ⰻ麊欽Ꟛ㨣
   䎃剢
   ,PUMJO׾فٗتؙءّٝח㼪Ⰵ
   

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8. ז׈,PUMJO׾㼪Ⰵׅ׷ךַ
   

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9. ,PUMJO㼪Ⰵ׾䚈ּ䗳銲כ֮׷ַ
   䚈ָזֽ׸לז׵זְ椚歋כזְ
   ,PUMJOׄׯזְה"OESPJE،فָٔ⡲׸זֻז׷

   ˘˘׻ֽדכזְ
   ֻ֮תד׮Ⱅ䒭؟ه٦ز鎉铂ָ㟓ִ׋׌ֽ
   ؟ه٦زָ竰竲ׁ׸׷㸜䗰䠬׾䩛חⰅ׸׋
   

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10. ׉׸ד׮,PUMJO׾㼪Ⰵׅ׷椚歋
    ؒٝآص،涸ז嚂׃ׁ
    倜׃ְ׮ךח鍗׸׵׸׷ٌثك٦ءّٝ
    ؒٝسِ٦ؠ٦ךًٔحزח׮ז׷鎉铂堣腉
    Ꟛ涪ח꧊⚥׃װְׅ
    ن؎ٓ٦فٖ٦ز׾㼰זֻדֹ׷
    膷ⰻךⳢ椚؎ً٦آ׾؝٦سח⿾僥׃װְׅ
    "OESPJEꟚ涪鎉铂ה׃גⰕ䒭ח؟ه٦ز
    Ꟛ涪ך䩛ָ姺ת׏ג׃תֲ〳腉䚍ָ嶊ִ׋
    

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11. ,PUMJOך㴍׃ְהֿ׹
    

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12. ن؎ٓ٦فٖ٦ز׾幾׵ֿׅהָדֹ׷
    -BNCEB䒭
    ًاحس׾א׌ֽ䭯א؎ٝة٦ؿؑ٦أ
    4JOHMF"CTUSBDU.FUIPE5ZQF
    -BNCEB䒭׾⢪׏גⱔꞿז鎸鶢ָ♶銲חז׷
    +BWBך׮ךה嫰鯰׃ג
    䒷侧ָאד♶銲ז㜥さכ剅ַזֻג׮葺ְ
    ⢪׻זְ䒷侧כˑ@˒ד邌植
    وآحؙؗ٦ٙ٦سˑJU˒
    

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13. Button b = (Button) findViewById(R.id.button);
    b.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
    // Your business logic
    }
    });
    "OESPJE+BWB %FGBVMU
    
    ⼡せؙٓأ׾⢪׏גٔأش٦׾إحزׅ׷ךדن؎ٓ٦فٖ٦زָ㢳ְ
    

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14. Button b = (Button) findViewById(R.id.button);
    b.setOnClickListener(view —> {
    // Your business logic
    });
    "OESPJE+BWB -BNCEB
    
    4JOHMF"CTUSBDU.FUIPEכ-BNCEB䒭׾⢪ֲֿהדأحؗٔה剅ֽ׷
    

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15. val b = findViewById(R.id.button) as Button
    b.setOnClickListener { view ->
    // Your business logic
    }
    b.setOnClickListener { _ ->
    // No use args
    }
    b.setOnClickListener {
    //“it” is View
    }
    ,PUMJO
    ,PUMJOד׮ずׄ״ֲח剅ֽ׷
    ⢪׻זְ䒷侧כ@ד邌ׅ
    䒷侧ָאז׵ל
    ˑJU˒ؗ٦ٙ٦سד⿫撑
    ׅ׷ֿה׮דֹ׷
    

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16. 䙼罋׾⿾僥׃װְׅ鎉铂堣腉
    أ؝٦فꟼ侧
    知患ז鎸鶢ך䩛⸔ֽ׾׃גֻ׸׷
    ؎ً٦آ鸐׶ך؎ٝأةٝأך欰䧭ח⤑ⵃ
    䭁䓸ꟼ侧
    ְא׮ךⳢ椚׾ًاحسך״ֲח䪔ִ׷
    傀㶷ךؙٓأח،سنحؙחًاحس׾鷄⸇
    JG䒭 USZ䒭 XIFO䒭
    ⦼׾鵤ֿׅהָדֹ׷
    

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17. public static MyFragment newInstance(String str) {
    MyFragment fragment = new MyFragment();
    Bundle args = fragment.getArguments();
    if (args == null) {
    args = new Bundle();
    }
    args.putString(KEY_TEXT, str);
    fragment.setArguments(args);
    return fragment;
    }
    +BWB
    葺ֻ֮׷ؿ؋ؙزٔػة٦ٝ
    

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18. ,PUMJO أ؝٦فꟼ侧
    
    fun newInstance(str: String) = MyFragment().apply {
    arguments = (arguments ?: Bundle()).apply {
    putString(KEY_TEXT, str)
    }
    }
    ˑBQQMZ˒כٖء٦غ׾「ֽ《׏גٖء٦غ׾鵤ׅ
    ➭ח׮MFU SVO XJUI BMTPָ֮׷׉׸׊׸䕵ⶴָ殯ז׷
    
    

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19. ,PUMJO أ؝٦فꟼ侧
    
    var test: String? = null
    var result: String = text ?: run {
    // Some processing
    "Hello, world"
    }
    ٕؒؽأ怴皾㶨ה穈׫さ׻ׇג䊩鴟ָOVMMך㜥さך⦼׾
    ⡦׵ַךⳢ椚ה穈׫さ׻ׇג《䖤דֹ׷
    ˟+BWB4DSJQUך⽯儗ꟼ侧䠬鋙
    

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20. +BWB
    public class StringUtils {
    public static boolean isNothing(String text) {
    return text == null || text.isEmpty();
    }
    }
    OVMMת׋כ瑞俑㶵⴨ַוֲַ׾ثؑحؙ׃׋ְ
    

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21. ,PUMJO DMBTT PCKFDU
    
    class StringUtils {
    companion object {
    fun isNothing(text: String?): Boolean {
    return text == null || text.isEmpty()
    }
    }
    }
    object StringUtils {
    fun isNothing(text: String?): Boolean {
    return text == null || text.isEmpty()
    }
    }
    TUBUJDًاحسך״ֲח鋅ׇ׷
    ˑPCKFDU˒׾⢪׏גءؚٕٝزٝד㹀纏ׅ׷
    

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22. ,PUMJO 䭁䓸ꟼ侧
    
    fun String.isNothing(): Boolean =
    this == null || this.isEmpty()
    var test: String? = null
    test.isNothing() // true
    㢌侧ך⚥魦ָˑOVMM˒ד׮/1&搀׃חثؑحָؙדֹ׷
    

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23. ת׋כծؽٕز؎ׁٝ׸גְ׷׮ך׾⢪ֲ
    @kotlin.internal.InlineOnly
    public inline fun CharSequence?.isNullOrEmpty(): Boolean =
    this == null || this.length == 0
    俑㶵⴨ךOVMMת׋כˑ瑞˒俑㶵ثؑحָؙדֹ׷
    @kotlin.internal.InlineOnly
    public inline fun CharSequence?.isNullOrBlank(): Boolean =
    this == null || this.isBlank()
    俑㶵⴨ךOVMMת׋כˑ瑞涯˒俑㶵ثؑحָؙדֹ׷
    

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24. +BWB JG俑
    
    String text = "This is java";
    String result;
    if (text.length % 2 == 0) {
    result = "Even";
    } else {
    result = "Odd";
    }
    JGˑ俑˒
    㢌侧㹀纏ךة؎ىؚٝד
    ⦼׾然㹀דֹזְ
    

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25. ,PUMJO JG䒭
    
    val text = "This is Kotlin"
    val result = if (text.length % 2 == 0) {
    "Even"
    } else {
    "Odd"
    }
    JGˑ䒭˒ה׃ג⦼׾鵤⽱ׅ׷ֿהָדֹ׷ךד
    㢌侧㹑鎉儗ח⦼׾然㹀ׇׁ׵׸׷
    JGFMTFぐـٗحؙך剑䖓ך遤ָ鐰⣣ׁ׸׷
    

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26. +BWB TXJUDI俑
    
    public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case android.R.id.home:
    finish();
    return true;
    default:
    return super.onOptionsItemSelected();
    }
    }
    ⢽ִלًصُ٦鼅䫛儗ךⳢ椚כ+BWBדכTXJUDI俑ד剅ֻֿהָ㢳ְ
    TXJUDI俑דכ⦼׾鵤ֿׅהָדֹזְךד؝٦سָ撕꧟חז׶װְׅ
    

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27. ,PUMJO XIFO䒭
    
    fun onOptionsItemSelected(item: MenuItem?): Boolean =
    when(item?.itemId) {
    android.R.id.home -> {
    finish()
    true
    }
    else -> super.onOptionsItemSelected()
    }
    ,PUMJOחTXJUDI俑כזֻծ➿׻׶חXIFO䒭׾⢪ֲ

    XIFO䒭כ⽃秪ז瘝⣣嫰鯰⟃㢩ח׮侧⦼ךٖٝآ䭷㹀װ㘗ثؑحؙ׮〳腉
    

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28. 㴍׃ְהֿ׹ָˑث٦ي˒חוֲ⸬ְגֻ׷ַ
    ِ٦أ؛٦أ׾邌׃׋؝٦سחז׶װְׅ
    搀꼽ָזְךד؝٦سٖؽُ٦ָװ׶װְׅ
    然钠ה䭷䶯ך怩׸ָ㼰זֻז׷
    Ꟛ涪ה然钠ךٕ٦ف׾넝鸞⻉ׅ׷ֿהָדֹ׷
    ِ٦ؠ٦פך⣣⦼䲿⣘ח꧊⚥דֹ׷
    

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29. 孡׾אֽ׋ְהֿ׹
    

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30. ,PUMJOח׮蕱ְהֿ׹ָ֮׷
    ًاحس侧
    ًاحسקו㟓ִ׷
    Lًاحسⵖꣲחעאַ׷〳腉䚍ָ넝ת׷
    "OOPUBUJPO1SPDFTTPS
    BQQCVJMEHSBEMF
    BOOPUBUJPO1SPDFTTPS̔LBQUח㢌ִ׷
    LBQUָ欰䧭ׅ׷؝٦سח㉏겗ָ֮׷ֿה׮֮׷
    

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31. וֲ㼪Ⰵ׾鹌׭גְַֻ
    

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32. $IBU8PSL،فٔך植朐
    ،فٔך؝٦سك٦أכ䎃湡ח瑱Ⰵ
    ⢪׏גְ׷⚺זٓ؎ـٓٔ䪮遭
    3FUSPMBNCEB
    3Y+BWB
    -JHIUXFJHIU4USFBN"1*
    "OOPUBUJPO1SPDFTTPS
    .VMUJEFY
    

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33. וַֿ׵,PUMJO׾⢪ְ㨣׭׷ַ
    Ⰻגך؝٦س׾,PUMJOחׅ׷ךכ⯓ָ黅ְ
    鿇ⴓ涸ח,PUMJO⻉׃גְֻ
    $IBU8PSLדכאך%JBMPH'SBHNFOUַ׵
    הג׮⽃秪זت؎،ؚٗ
    如ח傀㶷ך؝٦س׾א,PUMJO⻉
    ثٍحزٕ٦يך⡲䧭٥刿倜ך"DUJWJUZ
    ׁ׵ח׉ך䖓ծ倜鋉堣腉؝٦س׾,PUMJOד鷄⸇
    醱꧟זٗآحؙ׮Ⰵ׏גְ׷
    

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34. וֲװ׏גث٦يח嵴鷲ׇׁגְַֻ
    ,PUMJOأة٦زـحؙ
    ˑ鸐獥饔ץֿ劤˒׾Ⰻ㆞飑Ⰵ׃ג䩛⯋ח縧ֻ
    爡ⰻך,PUMJOثٍحزד㉔褏崞⹛
    +BWBה,PUMJOד剅ְ׋㜥さך䊴׾䫎珲
    فؙٕٔؒأزח铡僇؝ًٝز׾♨㻝ח鎸鶢
    +BWBדְֲהֿ׹ך⡦ַ
    ,PUMJOך؎ر؍ؔيך铡僇
    ٖؽُ٦䖓ثٍحزד椚鍑דֹ׋ַ然钠
    

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37. ث٦ي㼪Ⰵך铬겗
    

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38. ث٦يך稆㖑ה׃ג
    כׄ׭ַ׵+BWBד؝٦س׾剅ְגְ׋
    -BNCEB䒭׾䫺䫑זֻ「ֽⰅ׸׷ֿהָדֹ׋
    -JHIUXFJHIU4USFBN"1*׾⢪׏גְ׋
    0QUJPOBMך罋ִ倯ָ㕼〴ח֮׏׋ךדծ

    /VMMBCMFUZQFT /PO/VMMUZQFT׾

    أحה麩ㄤ䠬זֻ《׶鴥׬ֿהָדֹ׋
    穠卓ה׃ג
    ,PUMJOך؝٦سٖؽُ٦כ㉏겗זַ׏׋
    

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39. ׉׸ד׮
    ث٦يⰋ㆞ָ,PUMJO׾غٔغٔ剅ֽגכְזְ
    植㖈䩛ָֽגְ׷鿇ⴓך麩ְ׮֮׷ֽו׮
    ⡦׾וֿתד,PUMJOד剅ַֻכ㹀ת׏גְזְ
    ꬊず劍Ⳣ椚דBTZODBXBJU׾⢪׏גְַֻהַ
    Ⰻ㆞ָ駈⚛׫׾䲧ִ׵׸׷ַוֲַ
    铩ַ➂׌ָֽ,PUMJOח枠鹌׃גְֻ朐屣ָ

    ث٦يחה׏גծמְגכِ٦ؠ٦ך⣣⦼חז׷ַ
    ,PUMJOך؝٦س׾頾⫈ח׃גכְֽזְ
    

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40. 䩛ָֽכׄ׭ה׃ג
    ,PUMJO㼪Ⰵך⵸ח+BWBַ׵㨣׭ג׮葺ְַ׮
    "OESPJE4UVEJPַ׵כ㢩鿇خ٦ָٕ♶銲חז׷
    "OESPJE(SBEMF1MVHJO
    EFTVHBSخ٦ٕثؑ٦ٝ
    -BNCEB䒭װًاحسٔؿ؋ٖٝأָ⢪ִ׷
    傀㶷فٗآؙؑزח,PUMJO׾㼪Ⰵׅ׷ז׵ל
    㼭ֻׁ㨣׭׷
    +BWBך؝٦سָ؎ً٦آדֹ׷ּ׵ְ㼭ׁז׮ך
    

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41. ֶ׃תְ
    

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