在Visual Studio中编码时,我得到了一个未解决的外部符号错误 我不知道该怎么办我不知道怎么了。 你能帮我破译一下吗?我应该在哪里寻找什么样的错误?

1>Form.obj : error LNK2019: unresolved external symbol "public: class Field * __thiscall Field::addField(class Field *)" (?addField@Field@@QAEPAV1@PAV1@@Z) referenced in function "public: void __thiscall Form::parse(class std::basic_stringstream<char,struct std::char_traits<char>,class std::allocator<char> > &)" (?parse@Form@@QAEXAAV?$basic_stringstream@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)
1>Form.obj : error LNK2019: unresolved external symbol "public: virtual void __thiscall Field::parse(class std::basic_stringstream<char,struct std::char_traits<char>,class std::allocator<char> > &)" (?parse@Field@@UAEXAAV?$basic_stringstream@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "public: __thiscall InputField::InputField(class std::basic_stringstream<char,struct std::char_traits<char>,class std::allocator<char> > &)" (??0InputField@@QAE@AAV?$basic_stringstream@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z)
1>Form.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall Field::prompt(void)" (?prompt@Field@@UAEXXZ)
1>Form.obj : error LNK2001: unresolved external symbol "public: virtual class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall Field::getName(void)" (?getName@Field@@UAE?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@XZ)
1>Form.obj : error LNK2001: unresolved external symbol "public: virtual class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __thiscall Field::getType(void)" (?getType@Field@@UAE?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@XZ)
1>Form.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall Field::describe(void)" (?describe@Field@@UAEXXZ)
1>C:\Users\tomy\Documents\Visual Studio 2010\Projects\zapoctovkac++\Debug\zapoctovkac++.exe : fatal error LNK1120: 6 unresolved externals

当前回答

I believe most of the points regarding the causes and remedies have been covered by all contributors in this thread. I just want to point out for my 'unresolved external' problem, it was caused by a datatype defined as macro that gets substituted differently than expected, which results in that incorrect type being supplied to the function in question, and since the function with type is never defined, it couldn't have been resolved. In particular, under C/C++ -> Language, there is an attribute called 'Treat WChar_t As Built in Type, which should have been defined as 'No (/Zc:wchar_t-)' but did not in my case.

其他回答

它看起来缺少一个库或包含,你可以尝试找出你的库的什么类有getName, getType等…然后放到头文件中或者使用#include。

此外,如果这些碰巧来自外部库,请确保在项目文件中引用它们。例如,如果这个类属于abc。lib然后在你的Visual Studio

单击Project Properties。 进入配置属性,C/ c++, 生成,验证你指向abc。附加库位置 包括目录。在链接器,输入,确保你有 美国广播公司(abc)。附加依赖项下的lib。

检查是否包含了您所引用的解决方案中的所有源文件。

如果你没有在项目中包含Field类的源文件(以及实现),它将不会被构建,你将无法在编译期间进行链接。

或者,也许您正在使用静态或动态库,并且忘记告诉链接器有关.lib的信息?

确保你用

#ifndef YOUR_HEADER_H
#define YOUR_HEADER_H

// your header code here

#endif

如果你不这样做,就会发生不好的事情,包括这件事

我来这里寻找一个可能的解释,然后再仔细看看链接器错误之前的行。原来它是一个缺少全局声明的附加可执行文件!

指针

我有这个问题,并解决了它使用指针。我知道这不是你的问题,但我想我应该提一下,因为我真希望一小时前看到这个的时候它就在这里。我的问题是关于声明一个静态成员变量而没有定义它(定义需要在一些其他设置之后),当然指针不需要定义。同样基本的错误:P