接收器类型***例如消息是前向声明 [英] receiver type *** for instance message is a forward declaration

问题描述

在我的iOS5应用程序中，我有 NSObject States class，并尝试初始化它：

  states = [states init]; 
  

此处 init <$ c>中的方法$ c> States ：

   - （id）init 
 {
 if（（self = [super init]））
 {
 pickedGlasses = 0; 
} 
 
返回自我; 
} 
  

但行 states = [ state init];

接收者类型States例如消息是前向声明

这是什么意思？我做错了什么？

解决方案

这基本上意味着你需要导入包含状态声明的.h文件。 / p>

然而，您的代码中存在其他错误的很多。

• 你是在没有 + alloc 的情况下发出一个对象。这将无法正常工作


• 您将对象声明为非指针类型，无法正常工作


• 您不是在 -init 中调用 [super init] 。


• 您已声明标题中使用 @class 的类，但从未导入该类。

In my iOS5 app, I have NSObject States class, and trying to init it:

states = [states init];

here is init method in States:

- (id) init
{
    if ((self = [super init]))
    {
        pickedGlasses = 0;
    }

    return self;
}

But there is error in the line states = [states init];

receiver type "States" for instance message is a forward declaration

What does it mean? What am I doing wrong?

解决方案

That basically means that you need to import the .h file containing the declaration of States.

However, there is a lot of other stuff wrong with your code.

• You're -init'ing an object without +alloc'ing it. That won't work
• You're declaring an object as a non-pointer type, that won't work either
• You're not calling [super init] in -init.
• You've declared the class using @class in the header, but never imported the class.

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