Duilib嵌入CEF以及JavaScript与C++交互

转载:http://blog.****.net/foruok/article/details/50573612

转载:http://blog.****.net/foruok/article/details/50584985

转载:http://blog.****.net/mfcing/article/details/44539035

转载:https://github.com/fanfeilong/cefutil/blob/master/doc/CEF_JavaScript_Cpp.md

转载:https://blog.****.net/aseseven/article/details/79482515(CEF3加载本地HTML文件时中文路径乱码的问题解决办法)

转载:https://blog.****.net/u012778714/article/category/7003599

JS与Native代码交互，是在Render进程中，所以我们要实现CefRenderProcessHandler接口

一、JS 调用 C++

• JavaScript注册函数给Render进程，Render进程保存该JavaScript函数
• Render进程发消息通知Browser进程
• Browser进程处理后，回发消息给Render进程
• Render进程调用之前保存的JavaScript函数

1.带参数没有返回值

自己的APP类要继承于CefRenderProcessHandler

 #ifndef _CEFBROWSERAPP_H_
 #define _CEFBROWSERAPP_H_
 #include "include/cef_app.h"
 #include "CEFV8HandlerEx.h"

 class CCefBrowserApp
     : public CefApp
     , public CefBrowserProcessHandler
     , public CefRenderProcessHandler
 {
 public:
     CCefBrowserApp();

     virtual ~CCefBrowserApp();

 public:
     virtual CefRefPtr<CefBrowserProcessHandler> GetBrowserProcessHandler()OVERRIDE { return this; };

 public:
     // CefBrowserProcessHandler methods:
     virtual void OnContextInitialized();

     //CefRenderProcessHandler methods
     virtual void OnWebKitInitialized();

     CefRefPtr<CefRenderProcessHandler> GetRenderProcessHandler() OVERRIDE{ return this; }

     virtual void OnContextCreated(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);

     virtual void OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);

 protected:

     CefRefPtr<CCEFV8HandlerEx> m_v8Handler;

     IMPLEMENT_REFCOUNTING(CCefBrowserApp);
 };
 #endif //_CEFBROWSERAPP_H_

.cpp

 #include "CefBrowserApp.h"
 #include "stdafx.h"

 CCefBrowserApp::CCefBrowserApp()
     :m_v8Handler(new CCEFV8HandlerEx)
 {
 }

 CCefBrowserApp::~CCefBrowserApp()
 {
 }

 void CCefBrowserApp::OnContextInitialized()
 {
     // do nothing here, because we will create browser in my own dialog
 }

 void CCefBrowserApp::OnContextCreated(CefRefPtr<CefBrowser> browser,
                               CefRefPtr<CefFrame> frame,
                               CefRefPtr<CefV8Context> context)
 {
     // Retrieve the context's window object.
     CefRefPtr<CefV8Value> object = context->GetGlobal();

     // Create the "NativeLogin" function.
     CefRefPtr<CefV8Value> func = CefV8Value::CreateFunction("NativeLogin", m_v8Handler);

     // Add the "NativeLogin" function to the "window" object.
     object->SetValue("NativeLogin", func, V8_PROPERTY_ATTRIBUTE_NONE);
 }

 void CCefBrowserApp::OnWebKitInitialized()
 {
     std::string app_code =
         "var app;"
         "if (!app)"
         "    app = {};"
         "(function() {"
         "    app.GetId = function() {"
         "        native function GetId();"
         "        return GetId();"
         "    };"
         "})();";

     // Registered Javascript Function, which will be called by Cpp
     "  app.registerJavascriptFunction = function(name,callback) {"
         "    native function registerJavascriptFunction();"
         "    return registerJavascriptFunction(name,callback);"
         "  };"

         "})();";

     CefRegisterExtension("v8/app", app_code, m_v8Handler);//第一个参数不能为空，否则报错，这个名字可以自定义
 }

注：CefRegisterExtension的注释

// Example JavaScript extension code:
// <pre>
//   // create the 'example' global object if it doesn't already exist.
//   if (!example)
//     example = {};
//   // create the 'example.test' global object if it doesn't already exist.
//   if (!example.test)
//     example.test = {};
//   (function() {
//     // Define the function 'example.test.myfunction'.
//     example.test.myfunction = function() {
//       // Call CefV8Handler::Execute() with the function name 'MyFunction'
//       // and no arguments.
//       native function MyFunction();
//       return MyFunction();
//     };
//     // Define the getter function for parameter 'example.test.myparam'.
//     example.test.__defineGetter__('myparam', function() {
//       // Call CefV8Handler::Execute() with the function name 'GetMyParam'
//       // and no arguments.
//       native function GetMyParam();
//       return GetMyParam();
//     });
//     // Define the setter function for parameter 'example.test.myparam'.
//     example.test.__defineSetter__('myparam', function(b) {
//       // Call CefV8Handler::Execute() with the function name 'SetMyParam'
//       // and a single argument.
//       native function SetMyParam();
//       if(b) SetMyParam(b);
//     });
//
//     // Extension definitions can also contain normal JavaScript variables
//     // and functions.
//     var myint = 0;
//     example.test.increment = function() {
//       myint += 1;
//       return myint;
//     };
//   })();
// </pre>
// Example usage in the page:
// <pre>
//   // Call the function.
//   example.test.myfunction();
//   // Set the parameter.
//   example.test.myparam = value;
//   // Get the parameter.
//   value = example.test.myparam;
//   // Call another function.
//   example.test.increment();
// </pre>
///

 void CCefBrowserApp::OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context)
 {
     m_v8Handler = nullptr;
 }

OnContextCreated给window对象绑定了一个NativeLogin函数，这个函数将由ClientV8Handler类来处理，当HTML中的JS代码调用window.NativeLogin时，ClientV8Handler的Execute方法会被调用。

OnWebKitInitialized注册了一个名为app的JS扩展，在这个扩展里为app定义了GetId方法，app.GetId内部调用了native版本的GetId()。HTML中的JS代码可能如下：

alert(app.GetId());

当浏览器执行上面的代码时，CCEFV8HandlerEx的Execute方法会被调用,现在来看CCEFV8HandlerEx的实现

.h

 #ifndef _CEFV8HANDLEREX_H_
 #define _CEFV8HANDLEREX_H_

 #include "include/cef_v8.h"

 class CCEFV8HandlerEx : public CefV8Handler {
 public:
     CCEFV8HandlerEx();

     ~CCEFV8HandlerEx();
 public:
     virtual bool Execute(const CefString& name, CefRefPtr<CefV8Value> object, const CefV8ValueList& arguments, CefRefPtr<CefV8Value>& retval, CefString& exception) override;
 private:
     // Map of message callbacks.
     typedef std::map<std::pair<std::string, int>, std::pair<CefRefPtr<CefV8Context>, CefRefPtr<CefV8Value> > >CallbackMap;
     CallbackMap callback_map_;

 protected:
     IMPLEMENT_REFCOUNTING(CCEFV8HandlerEx);
 };
 #endif//_CEFV8HANDLEREX_H_

.cpp

 #include "CEFV8HandlerEx.h"
 #include "stdafx.h"
 #include <strsafe.h>

 CCEFV8HandlerEx::CCEFV8HandlerEx()
 {

 }

 CCEFV8HandlerEx::~CCEFV8HandlerEx()
 {
     // Remove any JavaScript callbacks registered for the context that has been released.
     if (!callback_map_.empty()) {
         CallbackMap::iterator it = callback_map_.begin();
         for (; it != callback_map_.end();) {
             if (it->second.first->IsSame(it->second.first))
                 callback_map_.erase(it++);
             else
                 ++it;
         }
     }
 }

 bool CCEFV8HandlerEx::Execute(const CefString& name  /*JavaScript调用的C++方法名字*/, CefRefPtr<CefV8Value> object /*JavaScript调用者对象*/, const CefV8ValueList& arguments /*JavaScript传递的参数*/, CefRefPtr<CefV8Value>& retval /*返回给JS的值设置给这个对象*/, CefString& exception/*通知异常信息给JavaScript*/)
 {
     if (name == "NativeLogin")
     {//Window Binding
         if (arguments.size() == )
         {
             CefString strUser = arguments.at()->GetStringValue();
             CefString strPassword = arguments.at()->GetStringValue();

             //TODO: doSomething() in native way

             CefRefPtr<CefProcessMessage> msg = CefProcessMessage::Create("login_msg");

             // Retrieve the argument list object.
             CefRefPtr<CefListValue> args = msg->GetArgumentList();

             // Populate the argument values.
             args->SetSize();
             args->SetString(, strUser);
             args->SetString(, strPassword);

             // Send the process message to the browser process.
             CefV8Context::GetCurrentContext()->GetBrowser()->SendProcessMessage(PID_BROWSER, msg);

             retval = CefV8Value::CreateInt();//函数的返回值 我们可以拿这个返回值做判断或者其他操作
                                                 //var result = window.NativeLogin(document.getElementById("userName").value, document.getElementById("password").value);
                                                 //document.getElementById("text").innerHTML = result

         }
         else
         {
             retval = CefV8Value::CreateInt();
         }
         return true;
     }
     else if (name == "GetId")
     {//JS Extensions
         if (arguments.size() == )
         {
             // execute javascript
             // just for test
             CefRefPtr<CefFrame> frame = CefV8Context::GetCurrentContext()->GetBrowser()->GetMainFrame();
             frame->ExecuteJavaScript("alert('Hello, I came from native world.')", frame->GetURL(), );

             // return to JS
             retval = CefV8Value::CreateString("");
             return true;
         }
     }
     // Function does not exist.
     return false;
 }

在Browser进程中接受Render进程发过来的消息

重写 virtual bool OnProcessMessageReceived(CefRefPtr<CefBrowser> browser, CefProcessId source_process,CefRefPtr<CefProcessMessage> message);这个虚函数

我把C++函数都写在了窗口类中，所以我对CCefBrowserEventHandler做了修改,把窗口指针传到Browser中，方便调用

.h

 #ifndef _CEFBROWSEREVENTHANDLER_H_
 #define _CEFBROWSEREVENTHANDLER_H_
 #include "include/cef_client.h"
 #include "include/base/cef_lock.h" //线程安全

 class CMainFrameWnd;

 class CCefBrowserEventHandler
     : public CefClient
     , public CefDisplayHandler            // 显示变化事件
     , public CefLoadHandler                // 加载错误事件
     , public CefLifeSpanHandler            // 声明周期事件
     //, public CefContextMenuHandler    // 上下文菜单事件
     //, public CefDialogHandler            // 对话框事件
     //, public CefDownloadHandler        // 下载事件
     //, public CefDragHandler            // 拖拽事件
     //, public CefFindHandler            // 查找事件
     //, public ...
 {
 public:
     CCefBrowserEventHandler(CMainFrameWnd* pMainFrame);

     virtual ~CCefBrowserEventHandler();

 public:
     // CefClient 事件处理器,如果没有对应处理器则默认使用内部处理器
     virtual CefRefPtr<CefDisplayHandler> GetDisplayHandler() OVERRIDE;
     virtual CefRefPtr<CefLifeSpanHandler> GetLifeSpanHandler() OVERRIDE;
     virtual CefRefPtr<CefLoadHandler> GetLoadHandler() OVERRIDE;

 public:
     // display handler method
     virtual void OnTitleChange(CefRefPtr<CefBrowser> browser, const CefString& title) OVERRIDE;

 public:
     // load handler method
     virtual void OnLoadError(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame,
         ErrorCode errorCode, const CefString& errorText, const CefString& failedUrl) OVERRIDE;

 public:
     // display handler meethod
     virtual void OnAfterCreated(CefRefPtr<CefBrowser> browser) OVERRIDE;
     virtual bool DoClose(CefRefPtr<CefBrowser> browser) OVERRIDE;
     virtual void OnBeforeClose(CefRefPtr<CefBrowser> browser) OVERRIDE;

     virtual bool OnProcessMessageReceived(CefRefPtr<CefBrowser> browser,
         CefProcessId source_process,
         CefRefPtr<CefProcessMessage> message);

     bool IsClosing() const { return m_bIsClosing; }

     CefRefPtr<CefBrowser> GetBrowser(){return m_Browser;} 

 protected:

     CefRefPtr<CefBrowser> m_Browser; 

     bool m_bIsClosing;

     CMainFrameWnd*      m_pMainWnd;

     IMPLEMENT_REFCOUNTING(CCefBrowserEventHandler);
     //由于CEF采用多线程架构，有必要使用锁和闭包来保证在多不同线程安全的传递数据。IMPLEMENT_LOCKING定义提供了Lock()和Unlock()方法以及AutoLock对象来保证不同代码块同步访问
     IMPLEMENT_LOCKING(CCefBrowserEventHandler);//必须包含#include "include/base/cef_lock.h"
 };

 #endif//_CEFBROWSEREVENTHANDLER_H_

.cpp

 #include "CefBrowserEventHandler.h"
 #include "stdafx.h"
 #include <sstream>
 #include <string>
 #include "include/cef_app.h"
 #include "include/wrapper/cef_closure_task.h"
 #include "include/wrapper/cef_helpers.h"
 #include "MainFrameWnd.h"

 CCefBrowserEventHandler::CCefBrowserEventHandler(CMainFrameWnd* pMainFrame)
     :m_bIsClosing(false)
     ,m_pMainWnd(pMainFrame)
 {

 }

 CCefBrowserEventHandler::~CCefBrowserEventHandler()
 {

 }

 CefRefPtr<CefDisplayHandler> CCefBrowserEventHandler::GetDisplayHandler()
 {
     return this;
 }

 CefRefPtr<CefLifeSpanHandler> CCefBrowserEventHandler::GetLifeSpanHandler()
 {
     return this;
 }

 CefRefPtr<CefLoadHandler> CCefBrowserEventHandler::GetLoadHandler()
 {
     return this;
 }

 void CCefBrowserEventHandler::OnTitleChange(CefRefPtr<CefBrowser> browser, const CefString& title)
 {

 }

 void CCefBrowserEventHandler::OnLoadError(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, ErrorCode errorCode,
                                           const CefString& errorText, const CefString& failedUrl)
 {
     CEF_REQUIRE_UI_THREAD();
     if (ERR_ABORTED == errorCode)
         return ;

     std::stringstream ss;
     ss <<    "<html><body bgcolor=\"white\">"
             "<h2>Failed to load URL " << std::string(failedUrl) <<
             " with error " << std::string(errorText) << " (" << errorCode <<
             ").</h2></body></html>";
     frame->LoadString(ss.str(), failedUrl);
 }

 void CCefBrowserEventHandler::OnAfterCreated(CefRefPtr<CefBrowser> browser)
 {
     CEF_REQUIRE_UI_THREAD();

     //base::AutoLock lock_scope(lock_);

     AutoLock lock_scope(this);

      m_Browser = browser;

 }

 bool CCefBrowserEventHandler::DoClose(CefRefPtr<CefBrowser> browser)
 {
     CEF_REQUIRE_UI_THREAD();

     //base::AutoLock lock_scope(lock_);
     AutoLock lock_scope(this);

     if(m_Browser)
     {
         // Set a flag to indicate that the window close should be allowed.
         m_bIsClosing = true;
     }

     return false;
 }

 void CCefBrowserEventHandler::OnBeforeClose(CefRefPtr<CefBrowser> browser)
 {
     CEF_REQUIRE_UI_THREAD();

     //base::AutoLock lock_scope(lock_);
     AutoLock lock_scope(this);

     if(m_Browser->IsSame(browser))
         m_Browser = NULL;
 }

 bool CCefBrowserEventHandler::OnProcessMessageReceived(CefRefPtr<CefBrowser> browser,
                                       CefProcessId source_process,
                                       CefRefPtr<CefProcessMessage> message)
 {
     const std::string& messageName = message->GetName();
     if (messageName == "login_msg")
     {
         // extract message
         CefRefPtr<CefListValue> args = message->GetArgumentList();
         CefString strUser = args->GetString();
         CefString strPassword = args->GetString();

         m_pMainWnd->CEFLoginJsCallCPP(strUser,strPassword);//窗口类的成员函数

                 //如果函数有返回值也可以通过向Render发送消息传递
         //send reply to render process
         CefRefPtr<CefProcessMessage> outMsg = CefProcessMessage::Create("login_reply");

         // Retrieve the argument list object.
         CefRefPtr<CefListValue> replyArgs = outMsg->GetArgumentList();

         // Populate the argument values.
         replyArgs->SetSize();
         replyArgs->SetInt(, );

         // Send the process message to the renderer process.
         browser->SendProcessMessage(PID_RENDERER, outMsg);

         return true;
     }

     return false;
 }

Browser进程处理完后向Render进程发了消息，The render process receives the IPC message处理

.h

 #ifndef _CEFBROWSERAPP_H_
 #define _CEFBROWSERAPP_H_
 #include "include/cef_app.h"
 #include "CEFV8HandlerEx.h"

 class CCefBrowserApp
     : public CefApp
     , public CefBrowserProcessHandler
     , public CefRenderProcessHandler
 {
 public:
     CCefBrowserApp();

     virtual ~CCefBrowserApp();

 public:
     virtual CefRefPtr<CefBrowserProcessHandler> GetBrowserProcessHandler()OVERRIDE { return this; };

 public:
     // CefBrowserProcessHandler methods:
     virtual void OnContextInitialized();

     //CefRenderProcessHandler methods
     virtual void OnWebKitInitialized();

     CefRefPtr<CefRenderProcessHandler> GetRenderProcessHandler() OVERRIDE{ return this; }

     virtual void OnContextCreated(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);

     virtual void OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);

     //收消息
     virtual bool OnProcessMessageReceived(CefRefPtr<CefBrowser> browser, CefProcessId source_process, CefRefPtr<CefProcessMessage> message);

 protected:

     CefRefPtr<CCEFV8HandlerEx> m_v8Handler;

     IMPLEMENT_REFCOUNTING(CCefBrowserApp);
 };
 #endif //_CEFBROWSERAPP_H_

.cpp

 #include "CefBrowserApp.h"
 #include "stdafx.h"

 CCefBrowserApp::CCefBrowserApp()
     :m_v8Handler(new CCEFV8HandlerEx)
 {
 }

 CCefBrowserApp::~CCefBrowserApp()
 {
 }

 void CCefBrowserApp::OnContextInitialized()
 {
     // do nothing here, because we will create browser in my own dialog
 }

 void CCefBrowserApp::OnContextCreated(CefRefPtr<CefBrowser> browser,
                               CefRefPtr<CefFrame> frame,
                               CefRefPtr<CefV8Context> context)
 {
     // Retrieve the context's window object.
     CefRefPtr<CefV8Value> object = context->GetGlobal();

     // Create the "NativeLogin" function.
     CefRefPtr<CefV8Value> func = CefV8Value::CreateFunction("NativeLogin", m_v8Handler);//第一个参数和SetValue参数保持一致,否则无法调用

     // Add the "NativeLogin" function to the "window" object.
     object->SetValue("NativeLogin", func, V8_PROPERTY_ATTRIBUTE_NONE);

     // Add the "register" function to the "window" object.
     object->SetValue("register",CefV8Value::CreateFunction("register", m_v8Handler),V8_PROPERTY_ATTRIBUTE_NONE);
 }

 void CCefBrowserApp::OnWebKitInitialized()
 {
     std::string app_code =
         "var app;"
         "if (!app)"
         "    app = {};"
         "(function() {"
         "    app.GetId = function() {"
         "        native function GetId();"
         "        return GetId();"
         "    };"
         "})();";

     // Registered Javascript Function, which will be called by Cpp
     "  app.registerJavascriptFunction = function(name,callback) {"
         "    native function registerJavascriptFunction();"
         "    return registerJavascriptFunction(name,callback);"
         "  };"

         "})();";

     CefRegisterExtension("v8/app", app_code, m_v8Handler);//第一个参数不能为空
 }

 void CCefBrowserApp::OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context)
 {
     m_v8Handler = nullptr;
 }

 bool CCefBrowserApp::OnProcessMessageReceived(CefRefPtr<CefBrowser> browser,CefProcessId source_process,CefRefPtr<CefProcessMessage> message)
 {
     const std::string& messageName = message->GetName();
     if (messageName == "login_reply")
     {
         // extract message
         CefRefPtr<CefListValue> args = message->GetArgumentList();
         bool status = args->GetBool();

         CefRefPtr<CefFrame> frame = browser->GetMainFrame();

         if (status)
         {
             frame->ExecuteJavaScript("IsSuccess();", frame->GetURL(), );
         }

         return true;
     }

     return false;
 }

 

2.JS CallBack

在OnContextCreated()函数中给window绑定函数

 // Create the "register" function.
     CefRefPtr<CefV8Value> func = CefV8Value::CreateFunction("register", m_v8Handler);//第一个参数和SetValue参数保持一致,否则无法调用

 // Add the "register" function to the "window" object.
     object->SetValue("register", func, V8_PROPERTY_ATTRIBUTE_NONE);

在Exectue()函数中处理

else if (name == "register")
{
    if (arguments.size() ==  && arguments[]->IsFunction())
    {
        CefRefPtr<CefV8Value> callback_func_ = arguments[];
        CefRefPtr<CefV8Context> callback_context_ = CefV8Context::GetCurrentContext();

        callback_func_->ExecuteFunction(NULL, arguments);//执行回调函数

        return true;
    }
}

在HTML的JavaScript里这样写

  function myFunc()
{
     // do something in JS.
      alert("callback");
}

//js CALLback
function CallBack()
{
     window.register(myFunc);
}

3.C++ 调用 JS

C++调用JS函数相对简单多了，因为CEF有接口可以直接使用CefFrame::ExecuteJavaScript，看看注释:

  ///
   // Execute a string of JavaScript code in this frame. The |script_url|
   // parameter is the URL where the script in question can be found, if any.
   // The renderer may request this URL to show the developer the source of the
   // error.  The |start_line| parameter is the base line number to use for error
   // reporting.
   ///
   /*--cef(optional_param=script_url)--*/
   virtual void ExecuteJavaScript(const CefString& code,
                                  const CefString& script_url,
                                  int start_line) =;

首先需要获取到我们的浏览器里的主框架对象，code是JS函数和传入参数的字符串，URL可以直接忽略。

 CefRefPtr<CefFrame> frame = m_handler->GetBrowser()->GetMainFrame();

 m_handler是我们自己定义的Handler对象

 /C++ 调用js方法
 //frame->ExecuteJavaScript(L"Test();",frame->GetURL(),0);//提示框
 //frame->ExecuteJavaScript(L"ModifyValue();",frame->GetURL(),0);//无参数函数
 frame->ExecuteJavaScript(L"ModifyValue('巴萨牛逼');",frame->GetURL(),);//有参数函数
9 如果参数是可变的，可以这样

CString strJsCode;
strJsCode.Format(L"setInstallStatus('%s','%s','%d');", lpData->strId.c_str(), strStatus, nPercent);

其中setInstallStatus是js函数，它有三个参数

我在HMTL里写的

  function Test()
{
     alert("js被C++非礼了");
}

 function ModifyValue( arr)
{
      //document.getElementById("text").innerHTML = "被修改了";

    alert(arr);
     document.getElementById("text").innerHTML = arr;
 }