Qt MinGW环境下使用CEF

环境

Clion ：2019.3.6

Qt ：5.12.12（MinGW 7.3.0）

CEF：cef_binary_87.1.14+ga29e9a3+chromium-87.0.4280.141_windows32

编译libcef_dll_wrapper

修改cmake 文件

修改根目录下的CMakeLists.txt

# 修改cmake 版本
cmake_minimum_required(VERSION 2.8.12.1...3.20.0)

# 设置c++标准
add_definitions("-std=c++11")

# 注释掉测试工程
#if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/tests")
#  add_subdirectory(tests/cefsimple)
#  add_subdirectory(tests/gtest)
#  add_subdirectory(tests/ceftests)
#endif()

#if(EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/tests/cefclient")
#  add_subdirectory(tests/cefclient)
#endif()

修改cef_variables.cmake

cef_variables.cmake文件在cmake目录下

主要是修改if(OS_WINDOWS)…endif()节点，因为是用MinGW编译，根据if(OS_LINUX)…endif()内容进行修改。修改原则：删除linux特有的内容，将if(OS_WINDOWS)…endif()节点下windows特有的属性合并进入。最后用修改后的的内容替换if(OS_WINDOWS)…endif()节点。

修改示例：

if(OS_WINDOWS)
  # Platform-specific compiler/linker flags.
  set(CEF_LIBTYPE STATIC)
  list(APPEND CEF_COMPILER_FLAGS
          -fno-strict-aliasing            # Avoid assumptions regarding non-aliasing of objects of different types
          -fPIC                           # Generate position-independent code for shared libraries
          -funwind-tables                 # Support stack unwinding for backtrace()
          -fvisibility=hidden             # Give hidden visibility to declarations that are not explicitly marked as visible
          --param=ssp-buffer-size=4       # Set the minimum buffer size protected by SSP (security feature, related to stack-protector)
          -pipe                           # Use pipes rather than temporary files for communication between build stages
          -pthread                        # Use the pthread library
          -Wall                           # Enable all warnings
          -Werror                         # Treat warnings as errors
          -Wno-missing-field-initializers # Don't warn about missing field initializers
          -Wno-unused-parameter           # Don't warn about unused parameters
          -Wno-error=comment              # Don't warn about code in comments
          -Wno-comment                    # Don't warn about code in comments
          )
  list(APPEND CEF_C_COMPILER_FLAGS
          -std=c99                        # Use the C99 language standard
          )
  list(APPEND CEF_CXX_COMPILER_FLAGS
          -fno-exceptions                 # Disable exceptions
          -fno-rtti                       # Disable real-time type information
          -fno-threadsafe-statics         # Don't generate thread-safe statics
          -fvisibility-inlines-hidden     # Give hidden visibility to inlined class member functions
          -std=gnu++11                    # Use the C++11 language standard including GNU extensions
          -Wsign-compare                  # Warn about mixed signed/unsigned type comparisons
          )
  list(APPEND CEF_COMPILER_FLAGS_DEBUG
          -O0                             # Disable optimizations
          -g                              # Generate debug information
          )
  list(APPEND CEF_COMPILER_FLAGS_RELEASE
          -O2                             # Optimize for maximum speed
          -fdata-sections                 # Enable linker optimizations to improve locality of reference for data sections
          -ffunction-sections             # Enable linker optimizations to improve locality of reference for function sections
          -fno-ident                      # Ignore the #ident directive
          -U_FORTIFY_SOURCE               # Undefine _FORTIFY_SOURCE in case it was previously defined
          -D_FORTIFY_SOURCE=2             # Add memory and string function protection (security feature, related to stack-protector)
          )
  list(APPEND CEF_LINKER_FLAGS
          -fPIC                           # Generate position-independent code for shared libraries
          -pthread                        # Use the pthread library
          -Wl,--disable-new-dtags         # Don't generate new-style dynamic tags in ELF
          -Wl,--fatal-warnings            # Treat warnings as errors
          -Wl,-rpath,.                    # Set rpath so that libraries can be placed next to the executable
          -Wl,-z,noexecstack              # Mark the stack as non-executable (security feature)
          -Wl,-z,now                      # Resolve symbols on program start instead of on first use (security feature)
          -Wl,-z,relro                    # Mark relocation sections as read-only (security feature)
          )
  list(APPEND CEF_LINKER_FLAGS_RELEASE
          -Wl,-O1                         # Enable linker optimizations
          -Wl,--as-needed                 # Only link libraries that export symbols used by the binary
          -Wl,--gc-sections               # Remove unused code resulting from -fdata-sections and -function-sections
          )
  list(APPEND CEF_COMPILER_DEFINES
          _FILE_OFFSET_BITS=64            # Allow the Large File Support (LFS) interface to replace the old interface
          )
  list(APPEND CEF_COMPILER_DEFINES_RELEASE
          NDEBUG                          # Not a debug build
          )

  include(CheckCCompilerFlag)
  include(CheckCXXCompilerFlag)

  CHECK_CXX_COMPILER_FLAG(-Wno-undefined-var-template COMPILER_SUPPORTS_NO_UNDEFINED_VAR_TEMPLATE)
  if(COMPILER_SUPPORTS_NO_UNDEFINED_VAR_TEMPLATE)
    list(APPEND CEF_CXX_COMPILER_FLAGS
            -Wno-undefined-var-template   # Don't warn about potentially uninstantiated static members
            )
  endif()

  CHECK_C_COMPILER_FLAG(-Wno-unused-local-typedefs COMPILER_SUPPORTS_NO_UNUSED_LOCAL_TYPEDEFS)
  if(COMPILER_SUPPORTS_NO_UNUSED_LOCAL_TYPEDEFS)
    list(APPEND CEF_C_COMPILER_FLAGS
            -Wno-unused-local-typedefs  # Don't warn about unused local typedefs
            )
  endif()

  CHECK_CXX_COMPILER_FLAG(-Wno-literal-suffix COMPILER_SUPPORTS_NO_LITERAL_SUFFIX)
  if(COMPILER_SUPPORTS_NO_LITERAL_SUFFIX)
    list(APPEND CEF_CXX_COMPILER_FLAGS
            -Wno-literal-suffix         # Don't warn about invalid suffixes on literals
            )
  endif()

  CHECK_CXX_COMPILER_FLAG(-Wno-narrowing COMPILER_SUPPORTS_NO_NARROWING)
  if(COMPILER_SUPPORTS_NO_NARROWING)
    list(APPEND CEF_CXX_COMPILER_FLAGS
            -Wno-narrowing              # Don't warn about type narrowing
            )
  endif()

  if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
    list(APPEND CEF_CXX_COMPILER_FLAGS
            -Wno-attributes             # The cfi-icall attribute is not supported by the GNU C++ compiler
            )
  endif()

  if(PROJECT_ARCH STREQUAL "x86_64")
    # 64-bit architecture.
    list(APPEND CEF_COMPILER_FLAGS
            -m64
            -march=x86-64
            )
    list(APPEND CEF_LINKER_FLAGS
            -m64
            )
  elseif(PROJECT_ARCH STREQUAL "x86")
    # 32-bit architecture.
    list(APPEND CEF_COMPILER_FLAGS
            -msse2
            -mfpmath=sse
            -mmmx
            -m32
            )
    list(APPEND CEF_LINKER_FLAGS
            -m32
            )
  endif()

  # Standard libraries.
  set(CEF_STANDARD_LIBS
          X11
          )

  # Standard libraries.
  set(CEF_STANDARD_LIBS
    comctl32.lib
    rpcrt4.lib
    shlwapi.lib
    ws2_32.lib
    )

  # CEF directory paths.
  set(CEF_RESOURCE_DIR        "${_CEF_ROOT}/Resources")
  set(CEF_BINARY_DIR          "${_CEF_ROOT}/$<CONFIGURATION>")
  set(CEF_BINARY_DIR_DEBUG    "${_CEF_ROOT}/Debug")
  set(CEF_BINARY_DIR_RELEASE  "${_CEF_ROOT}/Release")

  # CEF library paths.
  set(CEF_LIB_DEBUG   "${CEF_BINARY_DIR_DEBUG}/libcef.lib")
  set(CEF_LIB_RELEASE "${CEF_BINARY_DIR_RELEASE}/libcef.lib")

  # List of CEF binary files.
  set(CEF_BINARY_FILES
    chrome_elf.dll
    d3dcompiler_47.dll
    libcef.dll
    libEGL.dll
    libGLESv2.dll
    snapshot_blob.bin
    v8_context_snapshot.bin
    swiftshader
    )

  # List of CEF resource files.
  set(CEF_RESOURCE_FILES
    cef.pak
    cef_100_percent.pak
    cef_200_percent.pak
    cef_extensions.pak
    devtools_resources.pak
    icudtl.dat
    locales
    )
endif()

修改部分代码

include\internal\cef_string_wrappers.h

// 36行增加
#if defined(__MINGW32__)
#include <cstring>
#endif

include\base\internal\cef_atomicops_x86_msvc.h

// 82行修改
#if !(defined(_MSC_VER) && _MSC_VER >= 1400) && !defined(__MINGW32__)

include\base\cef_atomicops.h

// 179行修改
#if defined(OS_WIN) && (defined(COMPILER_MSVC) || defined(__MINGW32__)) && defined(ARCH_CPU_X86_FAMILY)

include\base\cef_bind_helpers.h

// 275 行修改
#if defined(OS_WIN) && defined (COMPILER_MSVC)
// 280 行修改
#if defined(OS_WIN) && defined (COMPILER_MSVC)

// 两外一种修改方式：注释掉宏判断 
//#if defined(OS_WIN)
//#pragma warning(push)
//#pragma warning(disable : 4624)
//#endif
  struct Base : public T, public BaseMixin {};
//#if defined(OS_WIN)
//#pragma warning(pop)
//#endif

如果需要编译64位版本，将__MINGW32__宏改为__MINGW64__即可（前提是你下载的是win64版源码）

如果需要编译高版本的CEF库，可以先编译，然后根据错误提示修改。（原则：CEF没有提供MinGW的编译方式，需要在原来的MSVC的基础行修改，错误一般是由于MSVC宏引起的）

编译

做完以上工作后可以直接编译了，我这里选择的是编译Relese版，编译完成后可以在cmake-build-release\libcef_dll_wrapper目录下找到libcef_dll_wrapper.a文件。

使用

• 新建Qt工程cef_client，将CEF中tests\cefsimple目录下的simple_app.cc,simple_app.h,simple_handler.cc,simple_handler.h,simple_handler_win.cc文件复制到cef_client目录下
• 将CEF下的inclue目录复制到cef_client/cef目录下
• 将libcef_dll_wrapper.a复制到cef_client/cef目录下
• 将CEF中Release目录下的libcef.lib复制到cef_client/cef目录下并修改扩展名为.a（是不是很意外，其实MinGW的链文件.a与VC的连接文件.lib本质上差不多，MinGW可以兼容.lib连接文件（前提是.lib中不包含vc特有的特性），如果要使用高版本的CEF库，可能需要升级MinGW的版本）

.pro文件

QT       += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
CONFIG += c++14

INCLUDEPATH +=
    $$PWD/cef/include

SOURCES += \
    main.cpp \
    MainWindow.cpp \
    simple_app.cc \
    simple_handler.cc \
    simple_handler_win.cc

HEADERS += \
    MainWindow.h \
    simple_app.h \
    simple_handler.h

FORMS += \
    MainWindow.ui

win32: LIBS += -L$$PWD/cef/ -lcef_dll_wrapper
win32: LIBS += -L$$PWD/cef/ -lcef

INCLUDEPATH += $$PWD/cef
DEPENDPATH += $$PWD/cef

编译完成后将CEF资源文件，和libcef.dll等相关库（Release目录下除过.lib文件）复制到编译好的程序目录

simple_app.cc文件中的OnContextInitialized函数，修改如下

void SimpleApp::OnContextInitialized() {
    return;
}

否则启动后会出现两个浏览器窗口

##　main.cpp

#include "MainWindow.h"
#include "simple_app.h"
#include "simple_handler.h"

#include <QApplication>

bool CefInit()
{
    CefEnableHighDPISupport();

    CefSettings settings;
    settings.no_sandbox = true;
    settings.multi_threaded_message_loop = true;

    HINSTANCE inc = GetModuleHandle(NULL);
    CefMainArgs mainArgs(inc);
    CefRefPtr<CefApp> app;
    app = new SimpleApp;
    return CefInitialize(mainArgs, settings, app.get(), NULL);
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    CefInit();
    MainWindow w;
    w.showMaximized();
    a.exec();
    return 0;
}

MainWindow.cpp

#include "MainWindow.h"
#include "ui_MainWindow.h"

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) {
    ui->setupUi(this);
    initBrowser();
}

MainWindow::~MainWindow() {
    delete ui;
}

void MainWindow::initBrowser() {
    CefWindowInfo cefWndInfo;
    QString strUrl = "https://www.baidu.com/";
    HWND wnd = (HWND)ui->fmBrowser->winId();
    RECT winRect;
    QDesktopWidget* pDeskTop = QApplication::desktop();
    QRect qtRect = pDeskTop->screenGeometry();
    winRect.left = qtRect.left();
    winRect.top = qtRect.top();
    winRect.right = qtRect.right();
    winRect.bottom = qtRect.bottom();
    cefWndInfo.SetAsChild(wnd, winRect);
    CefBrowserSettings cefBrowSetting;
    cef_browser_ev_ = CefRefPtr<SimpleHandler>(new SimpleHandler(true));
    CefBrowserHost::CreateBrowser(cefWndInfo, cef_browser_ev_, strUrl.toStdString(), cefBrowSetting, nullptr,nullptr);
    emit resize(qtRect.width(), qtRect.height());
}

void MainWindow::resizeEvent(QResizeEvent *event) {
    if (cef_browser_ev_.get() == NULL) {
        return;
    }
    QRect qtRect = ui->fmBrowser->rect();
    const BrowserList browList = cef_browser_ev_->GetBrowserList();

    if (!browList.empty()) {
        HWND wnd = browList.front()->GetHost()->GetWindowHandle();
        ::MoveWindow(wnd, qtRect.x(), qtRect.y(), qtRect.width(), qtRect.height(), true);
    }
}