在类型y的对象上找不到属性x [英] property x not found on object of type y

问题描述

这里的新手，正在使用可编程计算器.

Newbie here, working on a programmable calculator.

在模型类CalculatorBrain的接口中，我声明

In the interface of the model class CalculatorBrain, I declare

@property (nonatomic, strong) NSMutableArray *whatHappenedSinceLastClear;  

然后在实现中我还要声明

Then in the implementation I also declare

-(NSMutableArray *)whatHappenedSinceLastClear
{
if(!_whatHappenedSinceLastClear) _whatHappenedSinceLastClear = [[NSMutableArray alloc] init];
return _whatHappenedSinceLastClear;
}

然后

-(double)runProgram:(id)whatHappenedSinceLastClear
{
NSMutableArray *mutableCopyOfWhatHappenedSinceLastClear;
if ([program isKindOfClass:[NSArray class]]) {
    mutableCopyOfWhatHappenedSinceLastClear = [whatHappenedSinceLastClear mutableCopy];
}
return [self popOffProgramStack:mutableCopyOfWhatHappenedSinceLastClear];
}

但是在ViewController中，当我声明

But in the ViewController, when I declare

-(IBAction)testPressed:(id)sender
{
CalculatorBrain *brain = self.brain;   
brain = [[CalculatorBrain alloc] init];
NSMutableArray *program = brain.whatHappenedSinceLastClear;
[brain runProgram:program];
}

在行NSMutableArray *program = brain.whatHappenedSinceLastClear;中，我收到一条消息，指出在'CalculatorBrain *'类型的对象上找不到属性'whatHappenedSinceLastClear'.

in the line NSMutableArray *program = brain.whatHappenedSinceLastClear; I get a message that says "property 'whatHappenedSinceLastClear' not found on object of type 'CalculatorBrain *'.

我在做什么错了?

推荐答案

尝试一下: 替换:

NSMutableArray *program = brain.whatHappenedSinceLastClear;

作者

NSMutableArray *program = [brain whatHappenedSinceLastClear];

和在大脑中.h

-(NSMutableArray *)whatHappenedSinceLastClear;

这应该有效.

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