UnityでのLINQ活用例

2015/02/20(金)の勉強会の資料です。

※元々はSlideShareで公開していた資料です。

1. UnityͰͷLINQ׆༻ྫ ࣨ੕྄ଠ 2015/02/20(ۚ)
2. ࣭໰Ͱ͢
3. UnityͰήʔϜΛ࡞੒͍ͯ͠Δํʁ
4. LINQ஌͍ͬͯΔํʁ
5. LINQ࢖͍ͬͯΔํʁ
6. LINQ͕ͬͭΓ࢖͍ͬͯΔํʁ
7. ͋Γ͕ͱ͏͍͟͝·ͨ͠
8. UnityͰͷLINQͷ׆༻ࣄྫΛ௨͠ɺ LINQͷྑ͞΍ར༻ํ๏Λ঺հ͠·͢ɻ
9. ࠓ೔ͷ໨ඪ Έͳ͞Μʹ • LINQΛ࢖͏ͱίʔυ͕ಡΈ΍͘͢ͳΔ͜ͱΛ஌ͬͯ΋Β͏ • LINQΛ׆༻Ͱ͖Δγʔϯ͕ଟ͍͜ͱΛ஌ͬͯ΋Β͏ • LINQΛ࢖ͬͯΈΑ͏ɾษڧͯ͠ΈΑ͏ͱࢥͬͯ΋Β͏ • LINQʹ͜Μͳศརͳϝιου͋ͬͨΜͩͱ஌ͬͯ΋Β͏
10. UnityͰͷྫΛ௨ͯ͠ʂ
11. ͱ͜ΖͰ
12. ήʔϜ։ൃͰେ੾ͳ΋ͷ ͨ͘͞Μ͋Γ·͢ΑͶ
13. ͦͷதͷͻͱͭ
14. ؆ܿͰಡΈ΍͍͢ίʔυ
15. ͳ͔ͥͬͯʁ ಈ͚͹ಉ͡͡Όͳ͍͔ͬͯʁ
16. ࢓༷ɺมΘΓ·͢ΑͶʁ ϦϦʔεޙ΋Ξϓσ͠·͢ΑͶʁ
17. ʮԚ͍ίʔυͰͱΓ͋͑ͣಈ͘෺ʯ ୹ظతʹ͸ૣ͍͔΋͠Εͳ͍ ×"୹ظతͳ։ൃ଎౓ ̋!தɾ௕ظతͳ։ൃ଎౓
18. ࢓༷͸։ൃ్தͰมΘΓ·͢ΑͶʁ ؆ܿͰಡΈ΍͘͢حྷͳίʔυ ͜Εʹൺ΂ͯԚ͘௕͍ίʔυͷ ࢓༷มߋ͸ͱͯ΋େมʂ
19. ༡ͼͳ͕Βࢼߦࡨޡ͠໘ന͍෺Λ࡞Δ ͦΕʹ͸؆ܿͰಡΈ͍҆ίʔυ͕ඞཁʂ ͋ͱԚ͘௕͍ίʔυɺ·͡Ξϓσ͠ΜͲ͍ʂ
20. ಡΈ΍͍͢ίʔυ͸େ੾ ࢍ੒͍͚ͯͨͩ͠·͔͢ʁ
21. ͱ͜ΖͰࠓ೔ͷςʔϚ͸ LINQͰ͢
22. LINQΛ࢖͏ͱɺ ϦετͳͲͷίϨΫγϣϯΛѻ͏ίʔυ͕ɺ ؆ܿʹಡΈ΍͘͢ͳΓ·͢Αʂ
23. ͯ͞ɺLINQͱ͸
24. LINQͱ͸ ౷߹ݴޠΫΤϦ!(LINQ)!͸ɺڧྗͳΫΤϦػೳΛ!C#!ݴޠ͓Αͼ! Visual!Basic!ݴޠͷߏจ΁ͱ֦ு͢ΔɺVisual!Studio!2008!Ͱಋೖ ͞ΕͨػೳͷηοτͰ͢ɻ! MSDN%LINQΑΓh*ps:/ /msdn.microso7.com/ja:jp/library/bb397926.aspx
25. ΠϝʔδΘ͖·͢ʁ
26. ഑ྻͱ͔Ϧετͱ͔σΟΫγϣφϦͱ͔ γʔέϯε(↑ͷΑ͏ͳΦϒδΣͷू·Γ)Λ Λѻ͏ίʔυ͕LINQΛ࢖͏ͱ៉ྷʹॻ͚Δ ͬͯ͜ͱ͚ͩͱΓ͋͑ͣࠓ͸Πϝʔδ͍ͯͩ͘͠͞(ద౰Ͱ͍͢·ͤΜ) ࠓ೔͓࿩͢͠Δͷ͸ɺLINQ%to%ObjectsͰ͢ ࠓ೔ͷ࿩ͰʮLINQ͕࢖͑ΔΑ͏ʹͳΔʯͱ͸ͳΓ·ͤΜɻΈͳ͞Μʹศར͞Λ঺հ͠Α͏ͱࢥ͍·͢ɻ
27. ࣗݾ঺հ • ໊લ:ࣨ੕྄ଠ • ॴଐ:Fuller,)Inc. • ࢓ࣄ:UnityΛ༻͍ͨήʔϜ։ൃ • ౤ߘઌ:h3p:/ /qiita.com/RyotaMurohoshi • Twi3er:@RyotaMurohoshi • ίϛϡχςΟ:AndroidͷձUnity෦
28. ϥΠϒϥϦUniLinq࡞ͬͨΓ UniBookͰLINQʹ͍ͭͯॻ͍ͨΓ
29. LINQେ޷͖Ͱ͢ʂ ʮLINQͷͳ͍C#ͳΜͯC#͡Όͳ͍ʯ ͬͯݴ͏ํ΋͍·͕͢ɺࢲ΋ͦ͏ࢥ͍·͢ʂ
30. ͦΜͳࢲ͕ ͜͏͍͏෩ʹ࢖͑Δɺ͜Μͳঢ়گͰ࢖͑Δ ͱ͍͏ྫΛΨϯΨϯ঺հ͍͖ͯ͠·͢
31. ୈҰ෦ ࠓ͙͢ʹ࢖ͬͯཉ͍͠ϝιου3બ CountɾAllɾAny
32. ͜ΜͳΫϥε͕͋ͬͯ public class Monster { public int Id { get; set; } public string Name { get; set; } public int Hp { get; set; } /* தུ */ }
33. List<Monster>ͷதͰHp͕0ҎԼͷཁૉΛ਺͑Δ ͷΑ͏ͳϦετ಺ͷࢦఆͷ৚݅Λຬͨͨ͠ཁૉΛ਺͑Δ ͬͯ͜ͱ΍Γ·ͤΜʁ
34. Count ಛఆͷ৚݅Λຬͨͨ͠ཁૉΛ਺͑Δ
35. Hp͕0ҎԼͷཁૉɺͭ·ΓࢮΜͰ͍Δ Ϟϯελʔ(Monster)ͷ਺Λ਺͍͑ͨ
36. Α͋͘Δforeachɺifͷίʔυ List<Monster> monsterList = LoadMonsterList (); // LINQΛ࢖Θͳ͍ͱ int deadMonsterCount = 0; foreach (Monster monster in monsterList) { if(monster.Hp <= 0) { deadMonsterCount++; } }
37. Count ࢦఆͷ৚݅Λຬͨͨ͠ཁૉΛ਺͑Δ List<Monster> monsterList = LoadMonsterList (); // Hp͕0ҎԼͷཁૉͷ਺ʹ int deadMonsterCount = monsterList.Count ((Monster monster) => monster.Hp <= 0);
38. ͖ͬ͞ͷ2ͭͷίʔυ Ͳ͏ಡΊ·͢ʁ
39. ͜ͷίʔυɺͲ͏ಡΈ·͢ʁ List<Monster> monsterList = LoadMonsterList (); // LINQΛ࢖Θͳ͍ͱ int deadMonsterCount = 0; foreach (Monster monster in monsterList) { if(monster.Hp <= 0) { deadMonsterCount++; } }
40. intܕͷdeadMonsterCountΛ0ͰॳظԽ foreachจͰmonsterListΛ·Θ͢ ΋͠ཁૉͷmonsterͷHp͕0ҎԼͳΒ͹ deadMonsterCountΛΠϯΫϦϝϯτ
41. ͋ɺͭ·Γʂ HP͕0ҎԼͷϞϯελʔΛ਺͑Δͷ͔ʂ ͱ͍͏1ճ಄ͷதͰͷม׵͕ඞཁ
42. ҰํLINQ͸ʁͲ͏ಡΈ·͢ʁ // LINQΛ࢖͏ͱ List<Monster> monsterList = LoadMonsterList (); // Hp͕0ҎԼͷཁૉͷ਺ʹ int deadMonsterCount = monsterList.Count ((Monster monster) => monster.Hp <= 0);
43. intܕͷdeadMonsterCountΛ࣍ͷ஋ͰॳظԽ monsterList಺ͷ࣍ͷ৚݅Λຬͨ͢ཁૉ਺ͩʂ ৚݅͸ཁૉͷHP͕0ҎԼͩʂ
44. ΄΅ҙຯతʹɺ ʮHp͕0ҎԼͷϞϯελʔΛ਺͑Ζʂʯ ࠨ͔Βӈʹૉ௚ʹಡΊΔʂ
45. foreachจɺifจͷ͸ ʮͲ͏ॲཧ͍ͯ͠Δ͔ʯ͕ॻ͔Ε͍ͯΔ LINQͰ͸ ʮԿ͕͍͔ͨ͠ʯ͕ॻ͔Ε͍ͯΔ
46. ͔ͩΒLINQͷίʔυ͸ಡΈ΍͍͢ ͔͠΋؆ܿ
47. ͔͜͜Β͸جຊɺLINQ൛ͷΈͰ͘͘͞͞ߦ͖·͢
48. Any ಛఆͷ৚݅Λຬͨ͢ཁૉ͕ ଘࡏ͢Δ͔ௐ΂Δ
49. Any ಛఆͷ৚݅Λຬͨ͢ཁૉ͕ଘࡏ͢Δ͔ௐ΂Δ List<Monster> monsterList = LoadMonsterList (); // Hp͕0ҎԼͷϞϯελʔ͕ଘࡏ͢Ε͹true bool isExistDeadMonster = monsterList.Any((Monster monster) => monster.Hp <= 0);
50. All શͯͷཁૉ͕ࢦఆͷ৚݅Λ ຬ͔ͨ͢ௐ΂Δ
51. All શͯͷཁૉ͕ࢦఆͷ৚݅Λຬ͔ͨ͢ௐ΂Δ List<Monster> monsterList = LoadMonsterList (); // શͯͷϞϯελʔͷHp͕0ҎԼͳΒ͹true bool isAllMonsterDead = monsterList.All((Monster monster) => monster.Hp <= 0);
52. ࣍͸UnityͬΆ͍ͷͰ ͔ͭ ׂͱϚΠφʔͳ΍ͭΛ
53. ୈೋ෦ Editor֦ுͰ΋׆༂ OfType
54. OfType ࢦఆͷܕͷཁૉͷΈʹϑΟϧλϦϯά͠ɺ ࢦఆͷܕͷγʔέϯεʹม׵
55. Project΢Οϯυ΢தͰબ୒தͷ෺ͷதͰɺ ςΫενϟ(TextureΫϥε)ͷΈΛॲཧ͢Δ (UnityEditor֦ு)
56. • UnityEditor.Selec0onΫϥεͷobjectsϓϩύςΟΛར༻ • Selec0on.objects͸ݱࡏબ୒͍ͯ͠Δ΋ͷΛऔಘ • ܕ͸UnityEngine.Object[]Ͱऔಘ • ͜Εʹ͸౰વςΫενϟ(TextureΫϥε)Ҏ֎ͷ΋ͷ΋ؚ·ΕΔ • ͚ͲTextureͷΈΛର৅ʹ͍ͨ͠
57. ϑΟϧλϦϯάͱ͍͑͹Where ͜ΕΛisԋࢉࢠͱ͋Θͤͯ foreach (UnityEngine.Object target in Selection.objects.Where (o => o is Texture)){ // Ωϟετ͢Δ or asԋࢉࢠར༻͕ΊΜͲ͍ Texture texture = target as Texture; // ͜͜ͰTextureʹԿ͔͠Βͷॲཧ }
58. CastϝιουͰΩϟετ΋Ͱ͖·͕͢ foreach (Texture texture in Selection.objects .Where (o => o is Texture) .Cast<Texture>()){ // ͜͜ͰTextureʹԿ͔͠Βͷॲཧ }
59. ͦ͜ͰOfTypeͰ͢Αʂ
60. OfType ࢦఆͷܕͷཁૉͷΈʹϑΟϧλϦϯά͠ɺࢦఆͷܕͷγʔέϯεʹม׵ // Selection.objectsͷதͷཁૉΛTextureܕͷΈʹϑΟϧλϦϯά͠ɺ // IEnumerable<Texture>ʹม׵ foreach (Texture texture in Selection.objects.OfType<Texture> ()){ // ͜͜ͰTextureʹԿ͔͠Βͷॲཧ }
61. UnityͷEditor֦ுͰɺSelec.on͸ར༻γʔϯ͕ଟ͍ʂ (MenuItemͱ߹Θͤͯಋೖָ͕ʂ) ʮSelec%on.objects.OfType<Texture>7()ʯɺͥͻʂ ࣮ࡍʹ࢖ͬͨྫ͕ͪ͜Βʂ!h#p:/ /qiita.com/RyotaMurohoshi/items/b01e3cdb91fea96f4574
62. OfTypeϝιου ଞͰ͸NUnitLiteͱ͍͏ϥΠϒϥϦΛ࢖ͬͨࡍ System.Object͔Βಛఆͷܕ΁ͷม׵Ͱ΋࢖͍·ͨ͠
63. Editor֦ுͰͷLINQ׆༻ LINQɺ࣮͸iOSͰ໰୊͕͋Γ·͢ ͚ΕͲUnityEditor಺Ͱ͋Ε͹େৎ෉ʂ Editor֦ு͔Βར༻࢝͠ΊΔͷ͸Φεεϝʂ
64. ୈࡾ෦ ࢦఆͷ৚݅Λຬͨ͢ઌ಄ͷཁૉΛऔಘ͢Δ FirstɺFirstOrDefault
65. List<Monster>ͷதͰHp͕0ҎԼͷཁૉ͕Ұͭཉ͍͠ ͷΑ͏ͳϦετ಺ͷࢦఆͷ৚݅Λຬͨ͢ཁૉΛҰͭऔಘ͢Δ ͬͯ͜ͱ΍Γ·ͤΜʁ
66. First ࢦఆͷ৚݅Λຬͨ͢ઌ಄ͷཁૉΛऔಘ͢Δ ৚݅Λຬͨͨ͠ཁૉ͕ͳ͍৔߹͸ྫ֎ൃੜ
67. First ࢦఆͷ৚݅Λຬͨ͢ઌ಄ͷཁૉΛऔಘ͢Δɻ৚݅Λຬͨͨ͠ཁૉ͕ͳ͍৔߹͸ྫ֎ൃੜ List<Monster> monsterList = LoadMonsterList (); // ͻͱͭ΋Hp͕0ҎԼͷཁૉ͕ଘࡏ͠ͳ͍ͳΒྫ֎ൃੜ Monster deadMonster = monsterList .First ((Monster monster) => monster.Hp <= 0);
68. Firstϝιου͸ ৚݅Λຬͨ͢ཁૉ͕ͳ͍৔߹ྫ֎͕ൃੜʂ ͡Ό͋ྫ֎Λൃੜͨ͘ͳ͍৔߹ʁ AnyͰଘࡏνΣοΫͯ͋ͬͨ͠৔߹ͷΈɺ΋͘͠͸ɽɽɽ
69. FirstOrDefault ࢦఆͷ৚݅Λຬͨ͢ઌ಄ͷཁૉΛऔಘ͢Δ ৚݅Λຬͨͨ͠ཁૉ͕ͳ͍৔߹͸ ͦͷܕͷنఆ஋Λฦ͢
70. ৚݅Λຬͨͨ͠ཁૉ͕ͳ͍৔߹ɺ ʮنఆ஋Λฦ͢=nullΛฦ͢ʯ͡Όͳ͍ʂ ͜͜ཁ஫ҙʂ஋ܕͷنఆ஋͸null͡Όͳ͍ʂ
71. نఆ஋ • Ϋϥεܕͷ৔߹ɺnull • intͷ৔߹ɺ0 • floatͷ৔߹ɺ0.0F • boolͷ৔߹ɺfalse • Vector3ͷ৔߹ɺxɺyɺz͕શͯ0.0F
72. FirstOrDefault ࢦఆͷ৚݅Λຬͨ͢ઌ಄ͷཁૉΛऔಘ͢Δɻ৚݅Λຬͨͨ͠ཁૉ͕ͳ͍৔߹͸ͦͷܕͷنఆ஋Λฦ͢ List<Monster> monsterList = LoadMonsterList (); // ͻͱͭ΋Hp͕0ҎԼͷཁૉ͕ଘࡏ͠ͳ͍ͳΒMonsterΫϥεͷنఆ஋nullʹ Monster deadMonster = monsterList .FirstOrDefault ((Monster monster) => monster.Hp <= 0);
73. ͜͜Ͱ͞Βʹ΋͏Ұͭʂ
74. DefaultIfEmpty γʔέϯε͕ۭͳΒ͹Ҿ਺Ͱ౉ͨ͠΋ͷΛ །Ұͷཁૉͱ͢Δγʔέϯεʹม׵
75. Firstͱ૊Έ߹Θͤͯ͜Μͳ͜ͱ͕Ͱ͖Δ
76. DefaultIfEmpty γʔέϯε͕ۭͳΒ͹Ҿ਺Ͱ౉ͨ͠΋ͷΛ།Ұͷཁૉͱ͢Δγʔέϯεʹม׵ List<Monster> monsterList = LoadMonsterList (); Monster defaultMonster = GetDefaultMonster (); int targetId = GetTargetId (); // ࢦఆIDͷϞϯελʔΛ୳͢ɻͳ͔ͬͨΒdefaultMonsterʹɻ Monster targetMonster = monsterList .Where ((Monster monster) => monster.Id == targetId) .DefaultIfEmpty (defaultMonster) .First (); // ͜ͷΦʔόʔϩʔυ͸୯७ʹઌ಄ཁૉऔಘ
77. ͱ͜ΖͰ
78. σϦήʔτͱϥϜμࣜ • ʮ(Monster*monster)*=>*monster.Hp*<=*0ʯ͸ϥϜμࣜ • ʮϥϜμࣜʯͰ͸ͳ͘ʮσϦήʔτʯΛҾ਺ʹͱΔ • LINQͷଟ͘ͷϝιου͕Func<T,*TResult>ΛऔΔ • ϥϜμࣜͷ༻్ͷҰͭ͸σϦήʔτͷੜ੒ ৄ͘͠͸ʂɹh"p:/ /qiita.com/RyotaMurohoshi/items/740151bd772889cf07deɹʹ·ͱΊ·ͨ͠
79. ୈ࢛෦ ࢉज़ܭࢉܥ MaxɺMinɺSumɺAverage
80. ͜ΜͳΫϥεΛ࢖͍·͢ public class PlayLog { public int StageId { get; set; } public int Score { get; set; } public DateTime PlayedAt { get; set; } public TimeSpan PlayTime { get; set; } }
81. List<PlayLog>ͷཁૉͷதͰҰ൪େ͖͍ScoreΛٻΊΔ ͷΑ͏ͳϦετ಺ཁૉΛม׵ͯ͠ɺͦͷҰ൪େ͖͍஋ΛٻΊΔ ͬͯ͜ͱ΍Γ·ͤΜʁ
82. Max ֤ཁૉʹม׵Λࢪͦ͠ͷ࠷େ஋Λܭࢉ͢Δ
83. Max ֤ཁૉʹม׵Λࢪͦ͠ͷ࠷େ஋Λܭࢉ͢Δ List<PlayLog> playLogList = LoadPlayLogList (); // PlayLogListͷScoreͷ࠷େ஋ int maxScore = playLogList.Max ((PlayLog playLog) => playLog.Score);
84. Min ֤ཁૉʹม׵Λࢪͦ͠ͷ࠷খ஋Λܭࢉ͢Δ
85. Min ֤ཁૉʹม׵Λࢪͦ͠ͷ࠷খ஋Λܭࢉ͢Δ List<PlayLog> playLogList = LoadPlayLogList (); // PlayLogListͷScoreͷ࠷খ஋ int minScore = playLogList.Min ((PlayLog playLog) => playLog.Score);
86. Sum ֤ཁૉʹม׵Λࢪͦ͠ͷ߹ܭ஋Λܭࢉ͢Δ
87. Sum ֤ཁૉʹม׵Λࢪͦ͠ͷ߹ܭ஋Λܭࢉ͢Δ List<PlayLog> playLogList = LoadPlayLogList (); // PlayLogListͷScoreͷ߹ܭ஋ int sumOfScore = playLogList.Sum ((PlayLog playLog) => playLog.Score);
88. Average ֤ཁૉʹม׵Λࢪͦ͠ͷฏۉ஋Λܭࢉ͢Δ
89. Average ֤ཁૉʹม׵Λࢪͦ͠ͷฏۉ஋Λܭࢉ͢Δ List<PlayLog> playLogList = LoadPlayLogList (); // PlayLogListͷScoreͷฏۉ஋ double averageOfScore = playLogList.Average ((PlayLog playLog) => playLog.Score);
90. ͱ͜ΖͰ
91. LINQͱiOS(1) • Unity+iOSͩͱ࣮ػ࣮ߦ࣌ΤϥʔʹͳΔ͜ͱ͕͋Δ • ཧ༝͸AOTίϯύΠϧ͕͏·͍͍ͬͯ͘ͳ͍Έ͍ͨ • ͦΕΛղܾ͢ΔͨΊʹUniLinq͍ͬͯ͏΍ͭΛ࡞ͬͨ
92. LINQͱiOS(2) • IL2CPPొ৔ • IL2CPPͰେৎ෉͔ࢼͨ͠Βɺςετ͢Δ΍͕࣮ͭػͰΤϥʔʹ • AssemblyΫϥεͷCodePathϓϩύςΟ͕nullͳͷ͕ݪҼ • ࠓޙ΋ਖ਼͘͠ಈ͔͘Ͳ͏͔ͳͲɺܧଓͯ͠ௐ΂͍͖ͯ·͢ʂ
93. ୈޒ෦ ฒͼସ͑ OrderByɺOrderByDescending ThenByɺThenByDescending
94. List<PlayLog>ΛScroreͷ߱ॱͰฒͼม͑Δ ͷΑ͏ͳ੔ྻૢ࡞ ͬͯ΍Γ·ͤΜʁ
95. OrderBy ֤ཁૉʹม׵Λࢪ͠ ͦͷ݁ՌͰฒͼସ͑
96. OrderBy ֤ཁૉʹม׵Λࢪͦ͠ͷ݁ՌͰฒͼସ͑ List<PlayLog> playLogList = LoadPlayLogList (); // είΞͷ߱ॱͰฒͼସ͑ IEnumerable<PlayLog> orderedPlayLog = playLogList .OrderByDescending ((PlayLog playLog) => playLog.Score); OrderBy͸ঢॱͰฒͼସ͑ɺOrderByDescending͸߱ॱͰฒͼସ͑ ݩͷσʔλΛฒͼม͑ΔͷͰͳ͘ɺ৽ͨʹฒͼସ͑ͨγʔέϯεΛͭ͘Δ
97. ΋͠ಉ͡ScoreͳΒͲ͏͠Α͏ʁ ಉScoreͳΒ͹PlayTime͕୹͍ॱʹ͍ͨ͠৔߹͸ʁ
98. ΋͏Ұ౓OrderByΛݺͿͷ͸ؒҧ͍ʂ
99. ThenBy OrderByͰฒͼସ͑ͨ΋ͷͰɺ ಉධՁͩͬͨ΋ͷΛฒͼସ͑
100. ThenBy OrderByͰฒͼସ͑ͨ΋ͷͰɺಉධՁͩͬͨ΋ͷΛฒͼସ͑ List<PlayLog> playLogList = LoadPlayLogList (); // είΞͷ߱ॱͰฒͼସ͑ͯɺಉ఺ͳΒ͕࣌ؒ୹͍ํΛઌʹ IEnumerable<PlayLog> orderedPlayLog =ɹplayLogList .OrderByDescending ((PlayLog playLog) => playLog.Score) .ThenBy ((PlayLog playLog) => playLog.PlayTime);
101. ୈ࿡෦ εΩοϓͱऔಘ SkipɺTakeɺSkipWhileɺTakeWhile
102. σʔλΛը໘ʹ10ݸͣͭදࣔ ΠϯσοΫε0ͷ1ϖʔδ໨ɺ0൪໨͔Β9൪໨ ΠϯσοΫε1ͷ2ϖʔδ໨ɺ10൪໨͔Β19൪໨ ΠϯσοΫε2ͷ3ϖʔδ໨ɺ20൪໨͔Β29൪໨ ͬͯ͜ͱ΍Γ·ͤΜ
103. Skip%+%Take
104. Skip ઌ಄͔ΒҾ਺Ͱ౉ͨ͠ݸ਺͚ͩ ཁૉΛඈ͹͢
105. Take ઌ಄͔ΒҾ਺Ͱ౉ͨ͠ݸ਺͚ͩ ཁૉΛฦ͢
106. Skip+Take σʔλΛը໘ʹ10ݸͣͭදࣔɺࠓճ͸3ϖʔδ໨(ΠϯσοΫε͸2) List<PlayLog> playLogList = LoadPlayLogList (); int numPerPage = 10; int pageIndex = 2; int skipNum = numPerPage * pageIndex; // 3ϖʔδ໨(ΠϯσοΫε͸2)ɺ20൪͔Β10ݸͷཁૉΛऔಘ IEnumerable<PlayLog> selectedPlayLogs =ɹplayLogList .Skip (skipNum) .Take (numPerPage);
107. ࠓɺDateTimeܕͷPlayedAtͷঢॱͰPlayLog͕ฒΜͰ͍Δ ͋Δ࣌ࠁ͔Βɺଞͷ͋Δ࣌ࠁ·ͰͷσʔλΛऔಘ͍ͨ͠
108. SkipWhile)+)TakeWhile
109. SkipWhile ઌ಄͔ΒҾ਺Ͱ౉ͨ͠৚͕݅ਅͷؒ ཁૉΛඈ͹͢
110. TakeWhile ઌ಄͔ΒҾ਺Ͱ౉ͨ͠৚͕݅ਅͷؒ ཁૉΛฦ͢
111. SkipWhile)+)TakeWhile List<PlayLog> playLogList = LoadPlayLogList (); DateTime start = GetStartTime (); DateTime end = GetEndTime (); // PlayedAt͕startΑΓޙorಉ࣌ࠁͰɺendΑΓલͳཁૉΛऔಘ IEnumerable<PlayLog> selectedPlayLogs =ɹplayLogList .SkipWhile ((PlayLog playLog) => playLog.PlayedAt < start) .TakeWhile ((PlayLog playLog) => playLog.PlayedAt < end);
112. ୈࣣ෦ ͦͷଞΦεεϝ
113. ElementAt γʔέϯεதͷ ࢦఆͷΠϯσοΫεͷཁૉΛऔಘ
114. ⚪൪ΠϯσοΫεͷཁૉ͕ཉ͍͠ ͜͏͍͏࣌ɺ͋Γ·͢ΑͶɻͲ͏͠·͢ʁ ͋·Γॻ͔ͳ͍͔΋͠Εͳ͍͚ͲɺϦϑΝΫλϦϯάͷ్தͰඞཁͳ͜ͱ΋͋Δʁ
115. ଟ͘ͷLINQϝιουͷฦ஋ܕͰ͋ΔɺIEnumerable<T>ܕ͸ ΠϯσΫαͰཁૉʹΞΫηεͰ͖ͳ͍ʂ
116. ToArray͸μϝઈରʂ // ToArrayͰ഑ྻʹ͔ͯ͠ΒΞΫηεʁ // ޮ཰ѱ͍ʂʂʂ // playLogs͸IEnumerable<PlayLog>ܕ PlayLog index5PlayLog = playLogs.ToArray ()[5];
117. ElementAt // ΠϯσΫα͸ͳ͍͚ΕͲ // ElementAtϝιουͰΠϯσοΫεʹΞΫηεͰ͖Δ PlayLog index5PlayLog = playLogs.ElementAt (5);
118. ToDic&onary γʔέϯε͔ΒࣙॻΛ࡞Δ ΩʔΛࢦఆ͢ΔɻόϦϡʔ΋ࢦఆͰ͖Δɻ
119. ͜ΜͳΫϥεΛ࢖͍·͢ public class Item { public int Id { get; set; } public string Name { get; set; } public ItemType ItemType { get; set; } } public enum ItemType { Weapon, ConsumptionItem, ValuableItem }
120. List<Item>*͔ΒItemͷIdΛΩʔͱ͢Δ Dic$onary<int,-Item>Λͭ͘Δ Έ͍ͨͳ͜ͱͨ͋͘͠Γ·ͤΜʁ ͦΕLINQͰҰߦͰ͔͚·͢ʂ
121. ToDic&onary γʔέϯε͔ΒࣙॻΛ࡞Δ!(ͦͷ1) List<Item> itemList = LoadItemList (); // IdϓϩύςΟΛΩʔͱ͢ΔσΟΫγϣφϦͷੜ੒ // ΋͠Ωʔͷॏෳ͕͋ͬͨΒྫ֎͕ൃੜ Dictionary<int, Item> itemDict = itemList .ToDictionary((Item item) => item.Id);
122. ToDic&onary γʔέϯε͔ΒࣙॻΛ࡞Δ!(ͦͷ2) List<Item> itemList = LoadItemList (); // IdϓϩύςΟΛΩʔɺNameϓϩύςΟόϦϡʔͱ͢Δ // σΟΫγϣφϦͷੜ੒ // ΋͠Ωʔͷॏෳ͕͋ͬͨΒྫ֎͕ൃੜ Dictionary<int, string> itemDict = itemList.ToDictionary( (Item item) => item.Id, (Item item) => item.Name);
123. ToLookup γʔέϯε͔ΒILookupΛ࡞Δ άϧʔϓԽͨ͠ίϨΫγϣϯΛੜ੒
124. List<Item>*itemList͕͋ͬͯ Dic$onary<ItemType,2List<Item>>͕ཉ͍͠ LINQʹ͸Dic(onary<ItemType,5List<Item>>ʹࣅ͍ͯΔ ILookup<ItemType,.Item>͕࡞ΕΔϝιου͕͋Δ
125. ToLookup γʔέϯε͔ΒILookupΛ࡞Δ(άϧʔϓԽͨ͠ίϨΫγϣϯΛੜ੒) List<Item> itemList = LoadItemList (); // ILookup<ItemType, Items>͸ // Dictionary<ItemType,List<Item>>ʹࣅ͍ͯΔ ILookup<ItemType, Item> itemLookup = itemList. ToLookup((Item item) => item.ItemType); // σΟΫγϣφϦͷΑ͏ʹ[]ͱΩʔͰͦͷάϧʔϓʹΞΫηεͰ͖Δ IEnumerable<Item> weapons = itemLookup[ItemType.Weapon];
126. SelectMany ϦετͷϦετͷฏ׈ԽΛߦ͏
127. SelectMany ϦετͷϦετͷฏ׈ԽΛߦ͏(ͦͷ1) // ϞϯελʔͷϦετͷϦετ List<List<Monster>> listOfMonsterList = LoadListOfMonsterList (); // Ϟϯελʔͷγʔέϯεʹ IEnumerable<Monster> monsters = listOfMonsterList .SelectMany ((List<Monster> list) => list);
128. SelectMany͸ϦετͷϦετ͚͕ͩର৅͡Όͳ͍ ݁ߏ࢖͑Δʂ
129. ͜ΜͳΫϥε͕͋ͬͯ public class MonsterParty { public string Name { get; set; } // MonsterͷϦετɺ͜ͷϓϩύςΟ͕ϛι public List<Monster> MonsterList { get; set; } }
130. SelectMany ϦετͷϦετͷฏ׈ԽΛߦ͏(ͦͷ2) // ύʔςΟʔͷϦετ List<MonsterParty> monsterPartyList = LoadMonsterPartyList (); // Ϟϯελʔͷγʔέϯεʹ IEnumerable<Monster> monsters = monsterPartyList .SelectMany ((MonsterParty party) => party.MonsterList);
131. Dis$nct ॏෳΛআ͘
132. Dis$nct ॏෳΛআ͘ // γϯϓϧͳྫ int[] ids = new int[]{0, 1, 1, 2, 2, 2, 3, 3, 4}; // ॏෳ͕আ͔Ε͍ͯΔ IEnumerable<int> distinctedIds = ids.Distinct ();
133. Dis$nct ॏෳΛআ͘ // ύʔςΟʔʹಉ͡Ϟϯελʔ͸͍ͳ͍͕ɺଞͷύʔςΟʔʹ͸ಉ͡Ϟϯελʔ͕͍Δ List<MonsterParty> monsterPartyList = LoadMonsterPartyList (); // ॏෳͷແ͠ϞϯελʔͷIdͷγʔέϯεΛ࡞Δ IEnumerable<int> monsterIds = monsterPartyList // Ϟϯελʔͷγʔέϯεʹͯ͠ .SelectMany (party => party.MonsterList) // Idͷγʔέϯεʹͯ͠ .Select (monster => monster.Id) // ॏෳΛഉআ͢Δ .Distinct ();
134. ͪͳΈʹLINQʹ͸࣍ͷΑ͏ͳू߹ԋࢉΛߦ͏΋ͷ΋͋Γ·͢ ࠩू߹ΛٻΊΔ!Except ࿨ू߹ΛٻΊΔ!Union ੵू߹ΛٻΊΔ!Intersect
135. Join ೋͭͷγʔέϯεΛΩʔͰಥ߹
136. PlayLogΫϥεͱStageDataΫϥε͔ΒɺPlayDataΛ࡞Γ͍ͨ public class PlayLog { // StageͷIdͷΈͰStageͷ৘ใ͸ͳ͍ public int StageId { get; set; } public int Score { get; set; } /* தུ */ } public class StageData { public int Id { get; set; } public string Name { get; set; } /* தུ */ }
137. PlayLogΫϥεͱStageDataΫϥε͔ΒɺPlayDataΛ࡞Γ͍ͨ public class PlayData { // StageDataΫϥεͷ໊લ͔Β public string StageName { get; set; } // PlayLogΫϥεͷScore͔Β public int Score { get; set; } /* தུ */ }
138. List<PlayLog>ͳplayLogListͱ List<StageData>ͳstageDataList͔Β PlayDataͷγʔέϯεΛ࡞Γ͍ͨ
139. foreachͳྫ // foreachͳྫɺ௕͍ List<PlayData> playDataList = new List<PlayData> (); foreach(PlayLog playLog in playLogList) { StageData targetStageData = null; foreach(StageData stageData in stageDataList) { if (playLog.StageId == stageData.Id) { targetStageData = stageData; break; // nullͳ΍ͭ͸ͳ͍ΑͶͱ͍͏ίʔυ } } playDataList.Add (new PlayData { StageName = targetStageData.Name, Score = playLog.Score, }); }
140. LINQར༻ͳྫ // LINQར༻ͳྫɺ·ͩ௕͍ List<PlayData> playDataList = new List<PlayData> (); foreach(PlayLog playLog in playLogList) { StageData stageData = stageDataList.First (stage => stage.Id == playLog.StageId); playDataList.Add (new PlayData { StageName = stageData.Name, Score = playLog.Score, }); }
141. Joinͷྫ IEnumerable<PlayData> playDatas = playLogList.Join ( stageDataList, (PlayLog playLog) => playLog.StageId, // PlayLogͷΩʔ (StageData stageData) => stageData.Id, // StageDataͷΩʔ // ೋͭͷΩʔ͕ἧͬͨPlayLogͱStageData͕དྷΔ (PlayLog playLog, StageData stageData) => new PlayData { StageName = stageData.Name, Score = playLog.Score, });
142. ͯ͞
143. LINQͱͷ͖͍ͭ͋ํ • ΤϥʔʹͳΒͳ͍ϥΠϒϥϦΛ࡞Δor࢖͏ • ΤϥʔʹͳΔϝιουor࢖͍ํͰ࢖Θͳ͍ • Editor֦ுͷΈͰ࢖͏ • ΤϥʔʹͳΔ໰୊͕௚Δ·Ͱ଴ͭ
144. Կ͔࣭໰͋Γ·͢ʁ
145. ͯ͞ɺࠓ೔ͷ໨ඪͷ͓͞Β͍Ͱ͢
146. ࠓ೔ͷ໨ඪ Έͳ͞Μʹ • LINQΛ࢖͏ͱίʔυ͕៉ྷʹͳΔ͜ͱΛ஌ͬͯ΋Β͏ • LINQΛ࢖͑Δ׆༻γʔϯ͕ଟ͍͜ͱΛ஌ͬͯ΋Β͏ • LINQΛ࢖ͬͯΈΑ͏ɾษڧͯ͠ΈΑ͏ͱࢥͬͯ΋Β͏ • LINQʹ͜Μͳศརͳϝιου͋ͬͨΜͩͱ஌ͬͯ΋Β͏
147. ͍͔͕ͩͬͨͰ͠ΐ͏͔ʁ LINQ࢖ͬͯΈͨ͘ͳΓ·͔ͨ͠ʁ
148. ͋Γ͕ͱ͏͍͟͝·ͨ͠ʂ @RyotaMurohoshi