使用 TinyXML（在 c++ 中链接库）

Question

+嗨... 我是一个新手...我不知道如何在 C++ 中包含外部库。 这太难了。

我想使用 TinyXML。 所以我做了这个：

example2.cpp

#include <iostream>
#include "tinyxml.h"


void write_app_settings_doc( )  
{  
    TiXmlDocument doc;  
    TiXmlElement* msg;
    TiXmlDeclaration* decl = new TiXmlDeclaration( "1.0", "", "" );  
    doc.LinkEndChild( decl );  

    TiXmlElement * root = new TiXmlElement( "MyApp" );  
    doc.LinkEndChild( root );  

    TiXmlComment * comment = new TiXmlComment();
    comment->SetValue(" Settings for MyApp " );  
    root->LinkEndChild( comment );  

    TiXmlElement * msgs = new TiXmlElement( "Messages" );  
    root->LinkEndChild( msgs );  

    msg = new TiXmlElement( "Welcome" );  
    msg->LinkEndChild( new TiXmlText( "Welcome to MyApp" ));  
    msgs->LinkEndChild( msg );  

    msg = new TiXmlElement( "Farewell" );  
    msg->LinkEndChild( new TiXmlText( "Thank you for using MyApp" ));  
    msgs->LinkEndChild( msg );  

    TiXmlElement * windows = new TiXmlElement( "Windows" );  
    root->LinkEndChild( windows );  

    TiXmlElement * window;
    window = new TiXmlElement( "Window" );  
    windows->LinkEndChild( window );  
    window->SetAttribute("name", "MainFrame");
    window->SetAttribute("x", 5);
    window->SetAttribute("y", 15);
    window->SetAttribute("w", 400);
    window->SetAttribute("h", 250);

    TiXmlElement * cxn = new TiXmlElement( "Connection" );  
    root->LinkEndChild( cxn );  
    cxn->SetAttribute("ip", "192.168.0.1");
    cxn->SetDoubleAttribute("timeout", 123.456); // floating point attrib

    doc.SaveFile( "appsettings.xml" );  
} 


int main()
{
    write_app_settings_doc( );
  return 0;
}

只是一个示例文件。 所以..当我用以下命令编译它时：

g++ 示例2.cpp

我收到以下错误消息：

/tmp/cc6npUsW.o: In function `write_app_settings_doc()':
example2.cpp:(.text+0x13): undefined reference to `TiXmlDocument::TiXmlDocument()'
example2.cpp:(.text+0x43): undefined reference to `TiXmlDeclaration::TiXmlDeclaration(char const*, char const*, char const*)'
example2.cpp:(.text+0x58): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x8f): undefined reference to `TiXmlElement::TiXmlElement(char const*)'
example2.cpp:(.text+0xa4): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x112): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x132): undefined reference to `TiXmlElement::TiXmlElement(char const*)'
example2.cpp:(.text+0x147): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x17e): undefined reference to `TiXmlElement::TiXmlElement(char const*)'
example2.cpp:(.text+0x1cb): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x1f4): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x214): undefined reference to `TiXmlElement::TiXmlElement(char const*)'
example2.cpp:(.text+0x261): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x28a): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x2aa): undefined reference to `TiXmlElement::TiXmlElement(char const*)'
example2.cpp:(.text+0x2bf): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x2f6): undefined reference to `TiXmlElement::TiXmlElement(char const*)'
example2.cpp:(.text+0x30b): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x33d): undefined reference to `TiXmlElement::SetAttribute(char const*, char const*)'
example2.cpp:(.text+0x358): undefined reference to `TiXmlElement::SetAttribute(char const*, int)'
example2.cpp:(.text+0x373): undefined reference to `TiXmlElement::SetAttribute(char const*, int)'
example2.cpp:(.text+0x38e): undefined reference to `TiXmlElement::SetAttribute(char const*, int)'
example2.cpp:(.text+0x3a9): undefined reference to `TiXmlElement::SetAttribute(char const*, int)'
example2.cpp:(.text+0x3c9): undefined reference to `TiXmlElement::TiXmlElement(char const*)'
example2.cpp:(.text+0x3de): undefined reference to `TiXmlNode::LinkEndChild(TiXmlNode*)'
example2.cpp:(.text+0x40d): undefined reference to `TiXmlElement::SetAttribute(char const*, char const*)'
example2.cpp:(.text+0x42a): undefined reference to `TiXmlElement::SetDoubleAttribute(char const*, double)'
example2.cpp:(.text+0x43d): undefined reference to `TiXmlDocument::SaveFile(char const*) const'
/tmp/cc6npUsW.o: In function `TiXmlString::operator=(char const*)':
example2.cpp:(.text._ZN11TiXmlStringaSEPKc[TiXmlString::operator=(char const*)]+0x23): undefined reference to `TiXmlString::assign(char const*, unsigned int)'
/tmp/cc6npUsW.o: In function `TiXmlString::quit()':
example2.cpp:(.text._ZN11TiXmlString4quitEv[TiXmlString::quit()]+0xc): undefined reference to `TiXmlString::nullrep_'
/tmp/cc6npUsW.o: In function `TiXmlComment::TiXmlComment()':
example2.cpp:(.text._ZN12TiXmlCommentC1Ev[TiXmlComment::TiXmlComment()]+0x15): undefined reference to `TiXmlNode::TiXmlNode(TiXmlNode::NodeType)'
example2.cpp:(.text._ZN12TiXmlCommentC1Ev[TiXmlComment::TiXmlComment()]+0x1e): undefined reference to `vtable for TiXmlComment'
/tmp/cc6npUsW.o: In function `TiXmlText::TiXmlText(char const*)':
example2.cpp:(.text._ZN9TiXmlTextC1EPKc[TiXmlText::TiXmlText(char const*)]+0x17): undefined reference to `TiXmlNode::TiXmlNode(TiXmlNode::NodeType)'
example2.cpp:(.text._ZN9TiXmlTextC1EPKc[TiXmlText::TiXmlText(char const*)]+0x20): undefined reference to `vtable for TiXmlText'
example2.cpp:(.text._ZN9TiXmlTextC1EPKc[TiXmlText::TiXmlText(char const*)]+0x4f): undefined reference to `TiXmlNode::~TiXmlNode()'
/tmp/cc6npUsW.o: In function `TiXmlDocument::~TiXmlDocument()':
example2.cpp:(.text._ZN13TiXmlDocumentD1Ev[TiXmlDocument::~TiXmlDocument()]+0xb): undefined reference to `vtable for TiXmlDocument'
example2.cpp:(.text._ZN13TiXmlDocumentD1Ev[TiXmlDocument::~TiXmlDocument()]+0x24): undefined reference to `TiXmlNode::~TiXmlNode()'
collect2: ld returned 1 exit status

我主要是一名 java 开发人员，并且在 c++ 中使用外部库时遇到很多问题。 不知道什么时候发链接。何时包含。当我必须制作 -I/myincludepath/ 时，

这些文件位于同一文件夹中：

example.cpptinyxml.htinyxml.cpp tinystr.htinystr.cpp

有人可以帮助我吗？

Answer 1

首先，这些都不是库：

example.cpp tinyxml.h tinyxml.cpp tinystr.h tinystr.cpp

您需要找到tinyxml 库。这个位置应该在包的文档中描述，但假设它在 /foo 中（它不会）并且被称为 libtinyxml.a （它可能不会）。您可以像这样链接它：

g++ example2.cpp -L/foo -ltinyxml

它将 /foo 添加到链接路径并在其上查找 libtinyxml.a 。或者您可以简单地提供库的完整路径：

g++ example2.cpp /foo/libtinyxml.a

Answer 2

尝试类似的方法：

g++ example2.cpp tinyxml.cpp tinystr.cpp

Answer 3

你为什么不尝试学习Make呢？
其实很简单。从第 0 列开始的每一行都是一个目标及其先决条件。以选项卡开头的一行描述了构建目标的一个步骤。例如：

example2: example2.cpp example2.h
    g++ example2.cpp tinyxml.cpp tinystr.cpp -oexample2

或者，如果您有库：

example2: example2.cpp example2.h
    g++ example2.cpp -Ltinyxml -oexample2

实际上，您不必指定您正在使用的编译器。也许您在这里使用一个，而在另一个平台上使用另一个不同的。所以你可以使用适当的 make 变量：

example2: example2.cpp example2.h
    $(CXX) example2.cpp -Ltinyxml -oexample2

就是这样。将其保存为名为“Makefile”的文件，并且为了编译您的项目，只需键入：

$ make

如果需要，它将编译它。
进一步阅读：

http://www.gnu.org/software/make /manual/html_node/index.html

Answer 4

您应该编译 g++ main.cpp tinyxml.cpp tinystr.cpp tinyxmlparser.cpp tinyxmlerror.cpp

和这些文件(main.cpp tinyxml.cpp tinystr.cpp tinyxmlparser.cpp tinyxmlerror.cpp 和 tinyxml.h tinystr.h) 在编译时必须位于同一个目录下。

Answer 5

其实我昨天也遇到了这个问题。你可以尝试：g++ *.cpp