objective-c - Xcode拒绝确认编写良好的代码

Question

这个问题已经在这里有了答案:




已关闭8年。

Possible Duplicate:
error: expected specifier-qualifier-list before…in Objective C?

老实说，我不知道这是怎么回事。这段代码以前工作过，并且所有相关文件都写得很好并且可以单独编译(甚至是各自的 .m文件)，但是在我的OC项目中只有一个 .h文件，其中Xcode不断抛出相同的编译错误。有时每行多次，有时仅一次，但始终在 useCommand变量上。以下是整个受影响的 .h文件的屏幕截图和复制/粘贴的代码，这是唯一无法编译的文件。当我注释掉对 useCommand的每个引用时，该程序运行完美，但是当我取消注释时，再次发生这种情况。我什至甚至创建了一个新项目，然后将所有代码复制/粘贴到新文件中，并且仍然出现此错误。当我将 useCommand引用移至新行时，Xcode的错误随之而来。 有人知道Xcode发生了什么吗？ 我很确定这不是我的错误，因为我对代码进行了四重检查以确保它们都正确无误，并且我已经清理了几次目标。

类(class)

我的世界

//
//  Minecraftia.h
//  TextCraft
//
//  Created by Supuhstar on 4/3/12.
//  Copyright 2012 Blue Husky Programming. All rights reserved.
//

#import <Cocoa/Cocoa.h>
#import "Command.h"
#import "HelpCommand.h"
#import "UseCommand.h"
#import "GetCommand.h"
#import "LookCommand.h"
#import "IO.h"

@interface Minecraftia : NSObject
{
    HelpCommand *helpCommand;
    UseCommand *useCommand;
    GetCommand *getCommand;
    LookCommand *lookCommand;
}
-(id)init;

/**
 * If none has already been created, creates a static instance of Minecraftia
 * 
 * Returns the same instance of Minecraftia each time
 */
+(Minecraftia *)sharedInstance;

/**
 * Turns the given string into a command
 * If no matching command is found, nil is returned
 */
-(Command *)toCommand:(NSString *)input;

/**
 * The main method of the game, wherein all interactions happen
 */
-(void)play;

/**
 * Returns a random message to be used as splash text when the program is started
 */
-(NSString *)getASplash;

/**
 * Returns an NSArray of all the available commands
 */
-(NSArray*)getRegisteredCommands;

@property (retain, nonatomic, readonly) HelpCommand *helpCommand;
@property (retain, nonatomic, readonly) UseCommand *useCommand;
@property (retain, nonatomic, readonly) GetCommand *getCommand;
@property (retain, nonatomic, readonly) LookCommand *lookCommand;
@end

HelpCommand.h

//
//  HelpCommand.h
//  TextCraft
//
//  Created by Student4 on 4/9/12.
//  Copyright 2012 Blue Husky Programming. All rights reserved.
//

#import <Cocoa/Cocoa.h>
#import "Command.h"
#import "Minecraftia.h"

@interface HelpCommand : Command {

}

@end

HelpCommand.m

//
//  HelpCommand.m
//  TextCraft
//
//  Created by Student4 on 4/9/12.
//  Copyright 2012 Blue Husky Programming. All rights reserved.
//

#import "HelpCommand.h"


@implementation HelpCommand
-(bool)execute:(NSArray *)info
{
    NSString *helpString = @"Here are all the available commands:\n";
    NSArray *commands = [[Minecraftia sharedInstance] getRegisteredCommands];
    for(int i=0, l=[commands count]; i < l; i++)
    {
        helpString = [NSString stringWithFormat:@"\t> %@", [helpString stringByAppendingString:[[[commands objectAtIndex:i] class] triggerText]]];
    }
    MyLog([NSString stringWithFormat:@"%@\n\n", helpString]);
    return true;
}



+(NSString *)triggerText
{
    static NSString *triggerText = @"HELP";
    return triggerText;
}
@end

Answer 1

除非绝对需要 header ，否则使用@class而不是import，然后将导入移动到.m文件。现在，您将编译器置于一个循环中，Minecraftia.h导入UseCommand.h，而UseCommand.h导入Minecraftia.h。

应该看起来像这样:

#import <Cocoa/Cocoa.h>
#import "IO.h"

@class Command, HelpCommand, UseCommand, GetCommand, LookCommmand;

@interface Minecraftia : NSObject
{
    HelpCommand *helpCommand;
    UseCommand *useCommand;
    GetCommand *getCommand;
    LookCommand *lookCommand;
}

/* .... */

@end