c++ - Qt5-Windows : inconsistent dll linkage error and definition of dllimport static data member not allowed

Question

我正在尝试使用 Windows 10 构建项目和 Qt5.12 .小程序使用的是smtp协议(protocol)可用 here .我可以在我的 Windows 上确认我有 OpenSSL 1.1.1c 28 May 2019 .在我的 Ubuntu 19.04完全相同的程序会照常编译和运行，但不会在 Windows 上运行.

我在下面附上错误的打印屏幕；然而，这些主要有两种类型:

1) inconsistent dll linkage

2) definition of dllimport static data member not allowed

正在关注 this link似乎Windows需要它的“自己的”包含(即 #include <windows.... )但是在我的例子中是 smtp上述链接中的图书馆没有任何 #include <windows>并且不知道是否必须生成它们。从我找到的帖子看来他们没有

此外，我正在阅读 this post too因为我认为我可能有用，但没有任何信息可以帮助我解决问题

我挖了更多，实际上去了windows includes的地方是，以下是我能够找到的路径，但不知道这是否有用:

从我红色的所有帖子来看，问题似乎是，在这种特定情况下 Windows关于如何 .pro文件被写入。在我的下方.pro文件。请注意，我将此存储库克隆到我的 windows 10 中.

.pro

QT += quick quickcontrols2 concurrent network core gui

CONFIG += c++11

# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Refer to the documentation for the
# deprecated API to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

TARGET = SMTPEmail
TEMPLATE = lib
DEFINES += SMTP_BUILD
win32:CONFIG += dll


# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
        main.cpp \
        progressbardialog.cpp \
        robot.cpp \
        robotmanager.cpp \
        settings/emailaddress.cpp \
        settings/mimeattachment.cpp \
        settings/mimecontentformatter.cpp \
        settings/mimefile.cpp \
        settings/mimehtml.cpp \
        settings/mimeinlinefile.cpp \
        settings/mimemessage.cpp \
        settings/mimemultipart.cpp \
        settings/mimepart.cpp \
        settings/mimetext.cpp \
        settings/quotedprintable.cpp \
        settings/smtpclient.cpp \
        user.cpp \
        usermanager.cpp

RESOURCES += qml.qrc

# Additional import path used to resolve QML modules in Qt Creator's code model
QML_IMPORT_PATH =

# Additional import path used to resolve QML modules just for Qt Quick Designer
QML_DESIGNER_IMPORT_PATH =

HEADERS += \
    progressbardialog.h \
    robot.h \
    robotmanager.h \
    settings/SmtpMime \
    settings/emailaddress.h \
    settings/mimeattachment.h \
    settings/mimecontentformatter.h \
    settings/mimefile.h \
    settings/mimehtml.h \
    settings/mimeinlinefile.h \
    settings/mimemessage.h \
    settings/mimemultipart.h \
    settings/mimepart.h \
    settings/mimetext.h \
    settings/quotedprintable.h \
    settings/smtpclient.h \
    settings/smtpexports.h \
    user.h \
    usermanager.h

编辑

更具体地说，似乎每个标题都有问题，如下所示:

class SMTP_EXPORT EmailAddress : public QObject // <-- SMTP_EXPORT

这导致了我在下面复制的 smtpexports.h:

#ifndef SMTPEXPORTS_H
#define SMTPEXPORTS_H

#ifdef SMTP_BUILD
#define SMTP_EXPORT Q_DECL_EXPORT
#else
#define SMTP_EXPORT Q_DECL_IMPORT
#endif

#endif // SMTPEXPORTS_H

额外编辑

添加DEFINES += SMTP_BUILD后几乎所有错误都解决了但我还有两个错误，我在下面添加了一个打印屏幕:

非常感谢您指出正确的方向来解决这个问题。

Answer 1

这些文件被设计为使用添加源的定义 SMTP_BUILD 集进行编译，可以是库或可执行文件。你必须添加

DEFINES += SMTP_BUILD

到您的 pro 文件。