Objective-C switch語句的奇怪行爲

Question

我有一個遊戲使用全局整數position來瀏覽選項菜單。當每個屏幕都按下後退按鈕時，它會調用功能[self options]重新加載原始「選項」屏幕。我有一種感覺，這是非常愚蠢的東西我搞砸了。

現在，調用確定背部按鈕是否是這個函數的代碼：

if ([self touchIsInNode:[self childNodeWithName:@"back"] touchPoint:touchPoint]) { 
        // stuff should happen here 
       } 

隨着touchIsInNode:是處理水龍頭返回BOOL值自己的自定義方法（YES如果是） 。

命名爲每個屏幕backa，backb，backc等的後退按鈕的按鈕是一個可行的解決辦法，但它仍然呼叫在每個開關情況下，代碼不管position值。

下面是我在switch發言中事：

switch (position) { 
      // case 0 thru 3 are unrelated to the question... 0 is for the main menu, 1 is for the original logic for the "options" screen, 2 is for the end of the game, and 3 is to skip to the end of the intro screen. 
      case 4: 
      { 
       NSLog(@"position: %i", position); 
       if ([self touchIsInNode:[self childNodeWithName:@"backa"] touchPoint:touchPoint]) { 
        NSLog(@"store back button was pressed and [self options] is being called..."); 
        [self options]; 
       } 
       // store UI 
      } 
      case 5: 
      { 
       NSLog(@"position: %i", position); 
       if ([self touchIsInNode:[self childNodeWithName:@"backb"] touchPoint:touchPoint]) { 
        NSLog(@"stats back button was pressed and [self options] is being called..."); 
        [self options]; 
       } 
       // stats UI 
      } 
      case 6: 
      { 
       NSLog(@"position: %i", position); 
       if ([self touchIsInNode:[self childNodeWithName:@"backc"] touchPoint:touchPoint]) { 
        NSLog(@"about back button was pressed and [self options] is being called..."); 
        [self options]; 
       } 
       // about UI 
      } 
      case 7: 
      { 
       NSLog(@"position: %i", position); 
       if ([self touchIsInNode:[self childNodeWithName:@"backe"] touchPoint:touchPoint]) { 
        NSLog(@"dev options back button was pressed and [self options] is being called..."); 
        [self options]; 
       } 
       // dev options UI 
      } 
      case 8: 
      { 
       NSLog(@"position: %i", position); 
       if ([self touchIsInNode:[self childNodeWithName:@"backd"] touchPoint:touchPoint]) { 
        NSLog(@"purchased options back button was pressed and [self options] is being pressed..."); 
        [self options]; 
       } 
       // purchased options UI 
      } 
      default: 
      { 
       NSLog(@"INVALID POSITION: %i", position); 
       break; 
      } 
     } 
} 

我options方法是這樣的：

for (SKNode* node in [self children]) { 
    // fade out and remove each node if it is not "optionsButton" 
    if (![node.name isEqual:@"optionsButton"]) { 
     [node runAction:[SKAction fadeAlphaTo:0 duration:1] completion:^{ 
      [node removeFromParent]; 
     }]; 
    } else { 
     // if it is "optionsButton", perform an animation. 
     [node runAction:[SKAction scaleTo:1.5 duration:1]]; 
     [node runAction:[SKAction moveTo:CGPointMake(self.size.width/2, self.size.height - ((node.frame.size.height * (4.0/3.0))/node.yScale)) duration:1] completion:^{ 
      // afterwards, call a method that logs each node's name. 
      [self logEveryNode]; 
     }]; 
    } 
} 
position = 1; 
NSLog(@"position: %i", position); 

// processing labels 

// add in each child 

NSLog(@"options called, with %i nodes in [self children]", [self children].count); 

// fade in all of the labels 

然後，在選項菜單中每個子菜單，它們看起來像這樣（使用「商店」作爲模型）：

position = 4; 
for (SKNode* node in [self children]) { 
    if ([node.name isEqual:@"optionsButton"]) { 
     [node runAction:[SKAction scaleTo:(2.0/3.0) duration:1]]; 
     [node runAction:[SKAction moveTo:CGPointMake(self.size.width/2, self.size.height - (node.frame.size.height * (1.0/3.0))) duration:1]]; 
    } else if ([node.name isEqual:@"store"]) { 
     [node runAction:[SKAction scaleTo:1.5 duration:1]]; 
     [node runAction:[SKAction moveTo:CGPointMake(self.size.width/2, self.size.height - node.frame.size.height * 3) duration:1]]; 
    } else { 
     [node runAction:[SKAction fadeAlphaTo:0 duration:1] completion:^{ 
      [node removeFromParent]; 
     }]; 
    } 
} 

// draw UI for the store and move the back button accordingly 

SKLabelNode *back = [SKLabelNode labelNodeWithFontNamed:@"Cochin"]; 
back.alpha = 0; 
back.fontColor = [UIColor blackColor]; 
back.text = @"back"; 
back.name = @"backa"; 
back.fontSize = 44; 
back.position = CGPointMake(self.size.width/2, self.size.height * 0.5); 

[self addChild:back]; 

[back runAction:[SKAction fadeAlphaTo:1 duration:1]]; 

此代碼的結果是，即使在position的值更改爲1以表示回到options菜單後，也會執行每種情況。此外，didBeginTouches奇怪地被稱爲5次，雖然我只在模擬器中「挖掘」了一次屏幕。這裏是什麼，我有一個日誌更多的相關部分：

2015-05-23 01:10:40.581 game[25258:1981445] position: 4 
2015-05-23 01:10:40.581 game[25258:1981445] store back button was pressed and [self options] is being called... 
2015-05-23 01:10:40.582 game[25258:1981445] position: 1 
2015-05-23 01:10:40.588 game[25258:1981445] options called, with 10 nodes in [self children] 
2015-05-23 01:10:40.588 game[25258:1981445] position: 1 
2015-05-23 01:10:40.588 game[25258:1981445] position: 1 
2015-05-23 01:10:40.588 game[25258:1981445] position: 1 
2015-05-23 01:10:40.589 game[25258:1981445] position: 1 
2015-05-23 01:10:40.589 game[25258:1981445] INVALID POSITION: 1 

爲什麼每case運行，甚至default情況？似乎只有position == 4應該運行case 4而類似position == 500會運行default的情況。如果有幫助，選項菜單中有5個子菜單。

Answer 1

您需要在每個大小寫塊的末尾添加一個break語句。