libcurl 编译和链接器错误

发布于 2024-11-27 07:19:37 字数 4596 浏览 1 评论 0原文

我尝试在 Visual Studio C++ 中使用 libcurl 和 c++-cli 编写应用程序。它给了我这个错误

error C3867: "fr::Form1::write_data": Dem Funktionsaufruf fehlt die Argumentliste. Verwenden Sie "&fr::Form1::write_data", um einen Zeiger auf den Member zu erstellen. c:\users\ttg\documents\visual studio 2008\projects\fr\fr\Form1.h

,这意味着我应该将一些参数传递给 write_data。我不知道如何传递这些数据,在 libcurl 的文档中它显示了与我完全相同的代码,我只是复制并粘贴了它。我不知道我需要添加什么

此外,当我在表单之外声明此 write_data 函数时,我没有收到此错误,但收到链接器错误,例如:

Fehler  53  error LNK2031: p/invoke konnte nicht für ""extern "C" void __clrcall curl_easy_cleanup(void *)" (?curl_easy_cleanup@@$$J0YMXPAX@Z)" generiert werden. In den Metadaten fehlt die Aufrufkonvention.  fr.obj

意思是,元数据中缺少调用约定

这是我的代码:

#pragma once
#include <stdio.h>
#include <stdlib.h>
//#include <unistd.h>
#include <assert.h>
#include <string>
#include <curl/curl.h>
#include <sstream>
#include <curl/easy.h>
#include <iostream>
using namespace std;

namespace fr {

    using namespace System;
    using namespace System::ComponentModel;
    using namespace System::Collections;
    using namespace System::Windows::Forms;
    using namespace System::Data;
    using namespace System::Drawing;

    /// <summary>
    /// Zusammenfassung für Form1
    ///
    /// Warnung: Wenn Sie den Namen dieser Klasse ändern, müssen Sie auch
    ///          die Ressourcendateiname-Eigenschaft für das Tool zur Kompilierung verwalteter Ressourcen ändern,
    ///          das allen RESX-Dateien zugewiesen ist, von denen diese Klasse abhängt.
    ///          Anderenfalls können die Designer nicht korrekt mit den lokalisierten Ressourcen
    ///          arbeiten, die diesem Formular zugewiesen sind.
    /// </summary>
    public ref class Form1 : public System::Windows::Forms::Form
    {
    public:
        Form1(void)
        {
            InitializeComponent();
            //
            //TODO: Konstruktorcode hier hinzufügen.
            //
        }

    protected:
        /// <summary>
        /// Verwendete Ressourcen bereinigen.
        /// </summary>
        ~Form1()
        {
            if (components)
            {
                delete components;
            }
        }

    protected: 

    private:
        /// <summary>
        /// Erforderliche Designervariable.
        /// </summary>
        System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
        /// <summary>
        /// Erforderliche Methode für die Designerunterstützung.
        /// Der Inhalt der Methode darf nicht mit dem Code-Editor geändert werden.
        /// </summary>
        void InitializeComponent(void)
        {
            this->SuspendLayout();
            // 
            // Form1
            // 
            this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
            this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
            this->ClientSize = System::Drawing::Size(284, 262);
            this->Name = L"Form1";
            this->Text = L"Form1";
            this->ResumeLayout(false);

        }
#pragma endregion
    public:
 size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
        {
           // assert(bodyfile == (FILE*) stream); //this assertion fails, but when i comment it, code works. Why?
            int written = fwrite(ptr, size, nmemb, (FILE *)stream);
            return written;
        }
void proc(){
    CURL *curl_handle;
    const char *headerfilename = "head.out";
    FILE *headerfile;
    const char *bodyfilename = "body.html";
    FILE *bodyfile;
    curl_global_init(CURL_GLOBAL_ALL);
    curl_handle = curl_easy_init();
    curl_easy_setopt(curl_handle, CURLOPT_URL, "http://url");
    curl_easy_setopt(curl_handle, CURLOPT_NOPROGRESS, 1L);

    /*this causes error*/curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);

    headerfile = fopen(headerfilename,"w");
    if (headerfile == NULL) {
        curl_easy_cleanup(curl_handle);
        return;
    }
    bodyfile = fopen(bodyfilename,"w");
    if (bodyfile == NULL) {
        curl_easy_cleanup(curl_handle);
        return;
    }
    curl_easy_setopt(curl_handle,   CURLOPT_WRITEHEADER, headerfile);
    curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, bodyfile);
    curl_easy_perform(curl_handle);
    fclose(headerfile);
    fclose(bodyfile);
    curl_easy_cleanup(curl_handle);
    }//()proc 

    };
}

I try to code an app with libcurl and c++-cli in visual studio c++. It gives me this error

error C3867: "fr::Form1::write_data": Dem Funktionsaufruf fehlt die Argumentliste. Verwenden Sie "&fr::Form1::write_data", um einen Zeiger auf den Member zu erstellen. c:\users\ttg\documents\visual studio 2008\projects\fr\fr\Form1.h

which means that I should pass some arguments to write_data. I don't know how to pass these data, and in the documentation of libcurl it shows exactly the same code that I have,which I just copy and pasted. I don't know what I need to add

Furthermore when I declare this write_data function outside of the Form I don't get this error but I get linker errors like:

Fehler  53  error LNK2031: p/invoke konnte nicht für ""extern "C" void __clrcall curl_easy_cleanup(void *)" (?curl_easy_cleanup@@$J0YMXPAX@Z)" generiert werden. In den Metadaten fehlt die Aufrufkonvention.  fr.obj

meaning, missing call convetion in the metadata

This is my code:

#pragma once
#include <stdio.h>
#include <stdlib.h>
//#include <unistd.h>
#include <assert.h>
#include <string>
#include <curl/curl.h>
#include <sstream>
#include <curl/easy.h>
#include <iostream>
using namespace std;

namespace fr {

    using namespace System;
    using namespace System::ComponentModel;
    using namespace System::Collections;
    using namespace System::Windows::Forms;
    using namespace System::Data;
    using namespace System::Drawing;

    /// <summary>
    /// Zusammenfassung für Form1
    ///
    /// Warnung: Wenn Sie den Namen dieser Klasse ändern, müssen Sie auch
    ///          die Ressourcendateiname-Eigenschaft für das Tool zur Kompilierung verwalteter Ressourcen ändern,
    ///          das allen RESX-Dateien zugewiesen ist, von denen diese Klasse abhängt.
    ///          Anderenfalls können die Designer nicht korrekt mit den lokalisierten Ressourcen
    ///          arbeiten, die diesem Formular zugewiesen sind.
    /// </summary>
    public ref class Form1 : public System::Windows::Forms::Form
    {
    public:
        Form1(void)
        {
            InitializeComponent();
            //
            //TODO: Konstruktorcode hier hinzufügen.
            //
        }

    protected:
        /// <summary>
        /// Verwendete Ressourcen bereinigen.
        /// </summary>
        ~Form1()
        {
            if (components)
            {
                delete components;
            }
        }

    protected: 

    private:
        /// <summary>
        /// Erforderliche Designervariable.
        /// </summary>
        System::ComponentModel::Container ^components;

#pragma region Windows Form Designer generated code
        /// <summary>
        /// Erforderliche Methode für die Designerunterstützung.
        /// Der Inhalt der Methode darf nicht mit dem Code-Editor geändert werden.
        /// </summary>
        void InitializeComponent(void)
        {
            this->SuspendLayout();
            // 
            // Form1
            // 
            this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
            this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
            this->ClientSize = System::Drawing::Size(284, 262);
            this->Name = L"Form1";
            this->Text = L"Form1";
            this->ResumeLayout(false);

        }
#pragma endregion
    public:
 size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
        {
           // assert(bodyfile == (FILE*) stream); //this assertion fails, but when i comment it, code works. Why?
            int written = fwrite(ptr, size, nmemb, (FILE *)stream);
            return written;
        }
void proc(){
    CURL *curl_handle;
    const char *headerfilename = "head.out";
    FILE *headerfile;
    const char *bodyfilename = "body.html";
    FILE *bodyfile;
    curl_global_init(CURL_GLOBAL_ALL);
    curl_handle = curl_easy_init();
    curl_easy_setopt(curl_handle, CURLOPT_URL, "http://url");
    curl_easy_setopt(curl_handle, CURLOPT_NOPROGRESS, 1L);

    /*this causes error*/curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, write_data);

    headerfile = fopen(headerfilename,"w");
    if (headerfile == NULL) {
        curl_easy_cleanup(curl_handle);
        return;
    }
    bodyfile = fopen(bodyfilename,"w");
    if (bodyfile == NULL) {
        curl_easy_cleanup(curl_handle);
        return;
    }
    curl_easy_setopt(curl_handle,   CURLOPT_WRITEHEADER, headerfile);
    curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, bodyfile);
    curl_easy_perform(curl_handle);
    fclose(headerfile);
    fclose(bodyfile);
    curl_easy_cleanup(curl_handle);
    }//()proc 

    };
}

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评论(1

满意归宿 2024-12-04 07:19:37

我认为 write_data 方法应该是静态的...或者像你一样在 Form 类之外...关于链接器错误:摘录自 msdn 文章 尝试将本机函数导入纯映像时,请记住本机编译和纯编译之间的隐式调用约定有所不同。

I think write_data method should be made static... or outside Form class as you did... And about linker error: excerpt from msdn article When attempting to import a native function into a pure image, remember that the implicit calling conventions differ between native and pure compilations.

~没有更多了~
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