客体C枚举类型在重新分配对象变化

Question

我已经搜索并找不到断言。我知道这是我在这里想念的一件基本的事情。

我有一个枚举：

typedef enum { 
    NINETYBEND, NINETYBEND_FAST, NINETYBEND_SLOW, STRAIGHT 
} BlockTypeEnum; 

我想在我创造这样的对象来使用这些值：发生

BlockTypeEnum blockType = STRAIGHT; 
XMLLevelPiece* piece = [[XMLLevelPiece alloc] init]; 
[piece initPiece:blockType]; 

我的问题，当我尝试使用同一个变量两次。如果我使用枚举创建一个对象，更改枚举，然后使用它创建第二个对象，则第一个对象中的枚举将更改为第二枚举值。这不是我想要的。实施例下面：

BlockTypeEnum blockType = STRAIGHT; 

XMLLevelPiece* piece = [[XMLLevelPiece alloc] init]; 
[piece initPiece:blockType]; 

blockType = NINETYBEND_FAST; 

XMLLevelPiece* piece2 = [[XMLLevelPiece alloc] init]; 
[piece2 initPiece:blockType]; 

NSLog([NSString stringWithFormat:@"%d", [piece getBlockType]]); 
NSLog([NSString stringWithFormat:@"%d", [piece2 getBlockType]]); 

//BOTH BLOCK TYPES ARE NOW NINETYBEND_FAST, NOT WHAT I WANTED!! 

据我理解，枚举只是一个美化了INT，而不是一个指针，我加入到所述第一对象之后重新分配该变量。请有人能告诉我我错过了什么！谢谢，西蒙。

这是我的XMLPiece代码，谢谢！

#import "XMLLevelPiece.h" 
#import "BlockType.h" 
#import "GridCord.h" 
#import "BlockColor.h" 

@implementation XMLLevelPiece 

BlockTypeEnum mBlockType; 
BlockColorEnum mBlockColor; 
int mRotation; 
GridCord* mGridCords; 
BlockColorEnum mLeftColor; 
BlockColorEnum mTopColor; 
BlockColorEnum mRightColor; 
Boolean mRotatable; 
Boolean mMoveable; 
int mGroupID; 

-(id) init 
{ 
    if((self=[super init])) { 

    } 
    return self; 
} 

-(void)initPiece:(BlockTypeEnum)pBlockType pBlockColor:(BlockColorEnum)pBlockColor pRotation:(int)pRotation pGridCords:(GridCord*)pGridCords pLeftColor:(BlockColorEnum) pLeftColor pTopColor:(BlockColorEnum) pTopColor pRightColor:(BlockColorEnum) pRightColor pRotatable:(Boolean) pRotatable pMoveable:(Boolean) pMoveable pGroupID:(int) pGroupID 
{ 
    mBlockType = pBlockType; 
    mBlockColor = pBlockColor; 
    mRotation = pRotation; 
    mGridCords = pGridCords; 
    mLeftColor = pLeftColor; 
    mTopColor = pTopColor; 
    mRightColor = pRightColor; 
    mRotatable = pRotatable; 
    mMoveable = pMoveable; 
    mGroupID = pGroupID; 
} 

-(void)initPiece2 
{ 
    NSLog(@"poo"); 
} 

-(Boolean)getRotatable 
{ 
    return mRotatable; 
} 

-(Boolean)getMoveable 
{ 
    return mMoveable; 
} 

-(int) getGroupID 
{ 
    return mGroupID; 
} 

-(BlockColorEnum) getLeftColor 
{ 
    return mLeftColor; 
} 

-(BlockColorEnum) getTopColor 
{ 
    return mTopColor; 
} 

-(BlockColorEnum) getRightColor 
{ 
    return mRightColor; 
} 

-(BlockTypeEnum) getBlockType 
{ 
    return mBlockType; 
} 

-(BlockColorEnum) getBlockColor 
{ 
    return mBlockColor; 
} 

-(int) getRotation 
{ 
    return mRotation; 
} 

-(id) getGridCords 
{ 
    return mGridCords; 
} 

-(void) setRotatable:(Boolean) pRotatable 
{ 
    mRotatable = pRotatable; 
} 

-(void) setMoveable:(Boolean) pMoveable 
{ 
    mMoveable = pMoveable; 
} 

@end 

Answer 1

TL; DR

答案是 - 这不是你如何定义在Objective-C的ivars。我甚至不知道这应该如何表现，但我可以重现错误，如果我把它编码一样，你有。

我会对有更多知识的人感兴趣，以解释这些变量的行为/范围应该如何定义。

---

有在该代码

很多缺陷的你有没有实际显示的initPiece:。

带有所有参数的长init...可能是一个坏主意。通常只需要将一些东西添加到init中，以方便使用，或者如果没有它，对象就无法正常工作。

使用的get是不是真的正确在Objective-C

类应该可能更像

XMLLevelPiece.h

// You will need to import the header with the BlockTypeEnum defined 

@interface XMLLevelPiece : NSObject 

@property (nonatomic, assign) BlockTypeEnum blockType; 
// .. Other properties 

- (id)initWithPiece:(BlockTypeEnum)blockType; // I'm not so sure you need this 

@end 

XMLLevelPiece.m

定义

#import "XMLLevelPiece.h" 
#import "BlockType.h" 
#import "GridCord.h" 
#import "BlockColor.h" 

@implementation XMLLevelPiece 

@synthesize blockType = mBlockType; 

- (id)initWithPiece:(BlockTypeEnum)blockType; 
{ 
    self = [super init]; 
    if (self) { 
     mBlockType = blockType; 
    } 
    return self; 
} 

@end 

然后你可以使用它像

BlockTypeEnum blockType = STRAIGHT; 

XMLLevelPiece *p1 = [[XMLLevelPiece alloc] initWithPiece:blockType]; 

blockType = NINETYBEND_FAST; 

XMLLevelPiece *p2 = [[XMLLevelPiece alloc] initWithPiece:blockType]; 

NSLog(@"%d", p1.blockType); 
NSLog(@"%d", p2.blockType); 

我结果，其中：

2012-01-08 15:29:31.782 Untitled[1297:707] 3 
2012-01-08 15:29:31.791 Untitled[1297:707] 1 

---

可选观察

如果你可以用专用的初始化做掉，用法看起来更像：

BlockTypeEnum blockType = STRAIGHT; 

XMLLevelPiece *p1 = [[XMLLevelPiece alloc] init]; 
p1.blockType = blockType; 
// all other assignments 

blockType = NINETYBEND_FAST; 

XMLLevelPiece *p2 = [[XMLLevelPiece alloc] init]; 
p2.blockType = blockType; 
// all other assignments 

NSLog(@"%d", p1.blockType); 
NSLog(@"%d", p2.blockType); 

---

要删除几个superflous线，你可以删除本地blockType变量和值分配直奔对象：

XMLLevelPiece *p1 = [[XMLLevelPiece alloc] init]; 
p1.blockType = STRAIGHT; 

Answer 2

您的方法调用initWithPiece与定义不符。

电话：

[piece initPiece:blockType]; 

定义：

-(void)initPiece:(BlockTypeEnum)pBlockType pBlockColor:(BlockColorEnum)pBlockColor pRotation:(int)pRotation pGridCords:(GridCord*)pGridCords pLeftColor:(BlockColorEnum) pLeftColor pTopColor:(BlockColorEnum) pTopColor pRightColor:(BlockColorEnum) pRightColor pRotatable:(Boolean) pRotatable pMoveable:(Boolean) pMoveable pGroupID:(int) pGroupID 

评论：

一般方法与以上几个参数，最好在一个贫穷的想法调用。在这种情况下可能更好的是使用单个设置器。

Objective-C中按照Apple的惯例是命名不带“get”前缀的getter。实际上，get前缀表示通过引用参数返回的值，而不是返回结果。这种用法会混淆分析仪，如果使用ARC会导致问题。