Question

我仍然非常擅长用C语言编程，所以我使用Mingw在我的系统上编译。

我有以下程序，并提供了很多帮助。它将爆炸PKWare DCL压缩.vol存档（文件ID RESLIST）并将文件解压缩到指定的输出文件夹，为解压缩的文件提供原始.vol文件的修改日期。它应该用于Inno安装程序安装程序，我想看看我是否可以将其编译为.dll库我可以在我的.iss脚本中导入，即：

function VolEx( filename, outputpath: String ): Integer; external 'VolExA@volex.dll stdcall';

我通过http://www.mingw.org/wiki/sampleDLL阅读，但很难理解所有ifdefs和extern“C”的内容。

此外，我希望它能够更改我的安装程序中的WizardForm.FilenameLabel.Caption以匹配当前正在提取的文件（我知道这需要InnoTools InnoCallback http://www.sherlocksoftware.org/page.php?id=54;类似于FreeArc { {3}}）

Volex.c（包括blast.c和blast.h，来自这里：http://freearc.org/InnoSetup.aspx）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <sys/stat.h>
#include <time.h>
#include <utime.h>
#include "blast.h"

#define local static
#define VOLID "RESLIST"

struct inbuf {
    unsigned long left;
    unsigned char *buf;
    unsigned size;
    FILE *in;
};

struct stat statbuf;
time_t mtime;
time_t voltime;
struct utimbuf new_times;

local unsigned inf(void *how, unsigned char **buf)
{
    unsigned len;
    struct inbuf *inb = how;

    len = inb->size > inb->left ? inb->left : inb->size;
    len = fread(inb->buf, 1, len, inb->in);
    inb->left -= len;
    *buf = inb->buf;
    return len;
}

local int outf(void *how, unsigned char *buf, unsigned len)
{
    return fwrite(buf, 1, len, (FILE *)how) != len;
}

#define BUFSIZE 16384   /* must fit in unsigned */

local int extract(char *name, unsigned long len, FILE *in, char *path, time_t prevtime)
{
    int err;
    FILE *out;
    struct inbuf inb;
    unsigned char buf[BUFSIZE];

    inb.left = len;
    inb.buf = buf;
    inb.size = BUFSIZE;
    inb.in = in;
    mkdir(path);
    char outPath[strlen(path) + 20];
    strcpy(outPath, path);
    strcat(outPath, "\\");
    strcat(outPath, name);
    out = fopen(outPath, "wb");
    if (out == NULL)
        return 2;
    err = blast(inf, &inb, outf, out);
    fclose(out);
    if (stat(outPath, &statbuf) < 0) {
        perror(outPath);
        return 1;
    }
    mtime = statbuf.st_mtime; /* seconds since the epoch */

    new_times.actime = statbuf.st_atime; /* keep atime unchanged */
    new_times.modtime = prevtime;    /* set mtime to current time */
    if (utime(outPath, &new_times) < 0) {
        perror(outPath);
        return 1;
    }
    return err;
}

int main(int argc, char *argv[])
{
    if ( argc != 3 )
    {
        printf( "Usage: %s <vol> <output path>", argv[0] );
        return 1;
    }
    else
    {
        FILE *in = fopen(argv[1],"rb");
        unsigned long off, next;
        int err;
        unsigned char head[24];

        if (stat(argv[1], &statbuf) < 0) {
            perror(argv[1]);
            return 1;
        }
        voltime = statbuf.st_mtime; /* seconds since the epoch */

        if (fread(head, 1, 8, in) != 8 || memcmp(head, VOLID, 8)) {
            fprintf(stderr, "not the expected .vol format\n");
            return 1;
        }
        off = 8;
        while ((next = fread(head, 1, 24, in)) == 24) {
            off += 24;
            next = head[20] + (head[21] << 8) + ((unsigned long)(head[22]) << 16) +
               ((unsigned long)(head[23]) << 24);

            head[20] = 0;
            err = extract((char *)head, next - off, in, argv[2], voltime);
            if (err) {
                fprintf(stderr, "extraction error %d on %s\n", err, head);
                return 1;
            }
            off = next;
        }
        if (next)
            fprintf(stderr, "%lu bytes ignored at the end\n", next);
        return 0;
    }
}

Answer 1

假设您正在使用ANSI Inno Setup，请使用以下Inno签名：

function VolEx( filename, outputpath: String ): Integer; external 'VolExA@volex.dll stdcall';

将在您的DLL代码中需要以下C签名：

int __stdcall __declspec(dllexport) VolExA(const char *filename, const char *outputpath);

（如果您将DLL编译为C ++而不是C，则开头也需要extern "C"。）

您需要在DLL中声明此函数并将相应的代码从上面的“main”移动到其中，然后删除main函数并编译为DLL而不是控制台应用程序。

在担心通过回调反馈之前先让这部分工作 - 如果你遇到问题就提交一个单独的问题。

如何在Mingw中将C程序编译为dll，以便与Inno Setup＆amp;打回来

1 个答案: