Duilib嵌入CEF以及JavaScript與C++交互

本文轉載自查看原文 2016-12-06 16:47 4488 CEF開源庫

轉載:http://blog.csdn.net/foruok/article/details/50573612

轉載:http://blog.csdn.net/foruok/article/details/50584985

轉載:http://blog.csdn.net/mfcing/article/details/44539035

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

轉載:https://blog.csdn.net/aseseven/article/details/79482515(CEF3加載本地HTML文件時中文路徑亂碼的問題解決辦法)

轉載:https://blog.csdn.net/u012778714/article/category/7003599

JS與Native代碼交互，是在Render進程中，所以我們要實現CefRenderProcessHandler接口

一、JS 調用 C++

JavaScript注冊函數給Render進程，Render進程保存該JavaScript函數
Render進程發消息通知Browser進程
Browser進程處理后，回發消息給Render進程
Render進程調用之前保存的JavaScript函數

1.帶參數沒有返回值

自己的APP類要繼承於CefRenderProcessHandler

 1 #ifndef _CEFBROWSERAPP_H_
 2 #define _CEFBROWSERAPP_H_
 3 #include "include/cef_app.h"
 4 #include "CEFV8HandlerEx.h"
 5 
 6 class CCefBrowserApp
 7     : public CefApp
 8     , public CefBrowserProcessHandler
 9     , public CefRenderProcessHandler
10 {
11 public:
12     CCefBrowserApp();
13 
14     virtual ~CCefBrowserApp();
15 
16 public:
17     virtual CefRefPtr<CefBrowserProcessHandler> GetBrowserProcessHandler()OVERRIDE { return this; };
18 
19 public:
20     // CefBrowserProcessHandler methods:
21     virtual void OnContextInitialized();
22 
23     //CefRenderProcessHandler methods
24     virtual void OnWebKitInitialized();
25 
26     CefRefPtr<CefRenderProcessHandler> GetRenderProcessHandler() OVERRIDE{ return this; }
27 
28     virtual void OnContextCreated(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);
29 
30     virtual void OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);
31 
32 protected:
33 
34     CefRefPtr<CCEFV8HandlerEx> m_v8Handler;
35 
36     IMPLEMENT_REFCOUNTING(CCefBrowserApp);
37 };
38 #endif //_CEFBROWSERAPP_H_

.cpp

 1 #include "CefBrowserApp.h"
 2 #include "stdafx.h"
 3 
 4 
 5 CCefBrowserApp::CCefBrowserApp()
 6     :m_v8Handler(new CCEFV8HandlerEx)
 7 {
 8 }
 9 
10 CCefBrowserApp::~CCefBrowserApp()
11 {
12 }
13 
14 
15 void CCefBrowserApp::OnContextInitialized()
16 {
17     // do nothing here, because we will create browser in my own dialog
18 }
19 
20 void CCefBrowserApp::OnContextCreated(CefRefPtr<CefBrowser> browser,
21                               CefRefPtr<CefFrame> frame,
22                               CefRefPtr<CefV8Context> context)
23 {
24     // Retrieve the context's window object.
25     CefRefPtr<CefV8Value> object = context->GetGlobal();
26 
27     // Create the "NativeLogin" function.
28     CefRefPtr<CefV8Value> func = CefV8Value::CreateFunction("NativeLogin", m_v8Handler);
29 
30     // Add the "NativeLogin" function to the "window" object.
31     object->SetValue("NativeLogin", func, V8_PROPERTY_ATTRIBUTE_NONE);
32 }
33 
34 void CCefBrowserApp::OnWebKitInitialized()
35 {
36     std::string app_code =
37         "var app;" 
38         "if (!app)"
39         "    app = {};"
40         "(function() {"
41         "    app.GetId = function() {"
42         "        native function GetId();"
43         "        return GetId();"
44         "    };"
45         "})();";
46 
47     // Registered Javascript Function, which will be called by Cpp
48     "  app.registerJavascriptFunction = function(name,callback) {"
49         "    native function registerJavascriptFunction();"
50         "    return registerJavascriptFunction(name,callback);"
51         "  };"
52 
53         "})();";
54 
55 
56     CefRegisterExtension("v8/app", app_code, m_v8Handler);//第一個參數不能為空，否則報錯，這個名字可以自定義
57 }

注：CefRegisterExtension的注釋

// 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>
///

58 
59 void CCefBrowserApp::OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context)
60 {
61     m_v8Handler = nullptr;
62 }

OnContextCreated給window對象綁定了一個NativeLogin函數，這個函數將由ClientV8Handler類來處理，當HTML中的JS代碼調用window.NativeLogin時，ClientV8Handler的Execute方法會被調用。

OnWebKitInitialized注冊了一個名為app的JS擴展，在這個擴展里為app定義了GetId方法，app.GetId內部調用了native版本的GetId()。HTML中的JS代碼可能如下：

alert(app.GetId());

當瀏覽器執行上面的代碼時，CCEFV8HandlerEx的Execute方法會被調用,現在來看CCEFV8HandlerEx的實現

 1 #ifndef _CEFV8HANDLEREX_H_
 2 #define _CEFV8HANDLEREX_H_
 3 
 4 #include "include/cef_v8.h"
 5 
 6 class CCEFV8HandlerEx : public CefV8Handler {
 7 public:
 8     CCEFV8HandlerEx();
 9 
10     ~CCEFV8HandlerEx();
11 public:
12     virtual bool Execute(const CefString& name, CefRefPtr<CefV8Value> object, const CefV8ValueList& arguments, CefRefPtr<CefV8Value>& retval, CefString& exception) override;
13 private:
14     // Map of message callbacks.
15     typedef std::map<std::pair<std::string, int>, std::pair<CefRefPtr<CefV8Context>, CefRefPtr<CefV8Value> > >CallbackMap;
16     CallbackMap callback_map_;
17 
18 protected:
19     IMPLEMENT_REFCOUNTING(CCEFV8HandlerEx);
20 };
21 #endif//_CEFV8HANDLEREX_H_

.cpp

 1 #include "CEFV8HandlerEx.h"
 2 #include "stdafx.h"
 3 #include <strsafe.h>
 4 
 5 CCEFV8HandlerEx::CCEFV8HandlerEx()
 6 {
 7 
 8 }
 9 
10 CCEFV8HandlerEx::~CCEFV8HandlerEx()
11 {
12     // Remove any JavaScript callbacks registered for the context that has been released.
13     if (!callback_map_.empty()) {
14         CallbackMap::iterator it = callback_map_.begin();
15         for (; it != callback_map_.end();) {
16             if (it->second.first->IsSame(it->second.first))
17                 callback_map_.erase(it++);
18             else
19                 ++it;
20         }
21     }
22 }
23 
24 
25 bool CCEFV8HandlerEx::Execute(const CefString& name  /*JavaScript調用的C++方法名字*/, CefRefPtr<CefV8Value> object /*JavaScript調用者對象*/, const CefV8ValueList& arguments /*JavaScript傳遞的參數*/, CefRefPtr<CefV8Value>& retval /*返回給JS的值設置給這個對象*/, CefString& exception/*通知異常信息給JavaScript*/)
26 {
27     if (name == "NativeLogin") 
28     {//Window Binding
29         if (arguments.size() == 2)
30         {
31             CefString strUser = arguments.at(0)->GetStringValue();
32             CefString strPassword = arguments.at(1)->GetStringValue();
33 
34             //TODO: doSomething() in native way
35 
36             CefRefPtr<CefProcessMessage> msg = CefProcessMessage::Create("login_msg");
37 
38             // Retrieve the argument list object.
39             CefRefPtr<CefListValue> args = msg->GetArgumentList();
40 
41             // Populate the argument values.
42             args->SetSize(2);
43             args->SetString(0, strUser);
44             args->SetString(1, strPassword);
45 
46             // Send the process message to the browser process.
47             CefV8Context::GetCurrentContext()->GetBrowser()->SendProcessMessage(PID_BROWSER, msg);
48 
49 
50 
51             retval = CefV8Value::CreateInt(0);//函數的返回值 我們可以拿這個返回值做判斷或者其他操作
                                                 //var result = window.NativeLogin(document.getElementById("userName").value, document.getElementById("password").value);
                                                 //document.getElementById("text").innerHTML = result

52         }
53         else
54         {
55             retval = CefV8Value::CreateInt(2);
56         }
57         return true; 58  } 59     else if (name == "GetId") 60     {//JS Extensions
61         if (arguments.size() == 0) 62  { 63             // execute javascript 64             // just for test
65             CefRefPtr<CefFrame> frame = CefV8Context::GetCurrentContext()->GetBrowser()->GetMainFrame(); 66             frame->ExecuteJavaScript("alert('Hello, I came from native world.')", frame->GetURL(), 0); 67 
68             // return to JS
69             retval = CefV8Value::CreateString("72395678"); 70             return true; 71  } 72  } 73     // Function does not exist.
74     return false; 75 }

在Browser進程中接受Render進程發過來的消息

重寫 virtual bool OnProcessMessageReceived(CefRefPtr<CefBrowser> browser, CefProcessId source_process,CefRefPtr<CefProcessMessage> message);這個虛函數

我把C++函數都寫在了窗口類中，所以我對CCefBrowserEventHandler做了修改,把窗口指針傳到Browser中，方便調用

 1 #ifndef _CEFBROWSEREVENTHANDLER_H_
 2 #define _CEFBROWSEREVENTHANDLER_H_
 3 #include "include/cef_client.h"  
 4 #include "include/base/cef_lock.h" //線程安全
 5 
 6 
 7 class CMainFrameWnd;
 8 
 9 class CCefBrowserEventHandler
10     : public CefClient
11     , public CefDisplayHandler            // 顯示變化事件
12     , public CefLoadHandler                // 加載錯誤事件
13     , public CefLifeSpanHandler            // 聲明周期事件
14     //, public CefContextMenuHandler    // 上下文菜單事件
15     //, public CefDialogHandler            // 對話框事件
16     //, public CefDownloadHandler        // 下載事件
17     //, public CefDragHandler            // 拖拽事件
18     //, public CefFindHandler            // 查找事件
19     //, public ...
20 {
21 public:
22     CCefBrowserEventHandler(CMainFrameWnd* pMainFrame);
23 
24     virtual ~CCefBrowserEventHandler();
25 
26 public:
27     // CefClient 事件處理器,如果沒有對應處理器則默認使用內部處理器
28     virtual CefRefPtr<CefDisplayHandler> GetDisplayHandler() OVERRIDE;
29     virtual CefRefPtr<CefLifeSpanHandler> GetLifeSpanHandler() OVERRIDE;
30     virtual CefRefPtr<CefLoadHandler> GetLoadHandler() OVERRIDE;
31 
32 public:    
33     // display handler method
34     virtual void OnTitleChange(CefRefPtr<CefBrowser> browser, const CefString& title) OVERRIDE;
35 
36 public:
37     // load handler method
38     virtual void OnLoadError(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, 
39         ErrorCode errorCode, const CefString& errorText, const CefString& failedUrl) OVERRIDE;
40 
41 public:
42     // display handler meethod
43     virtual void OnAfterCreated(CefRefPtr<CefBrowser> browser) OVERRIDE;
44     virtual bool DoClose(CefRefPtr<CefBrowser> browser) OVERRIDE;
45     virtual void OnBeforeClose(CefRefPtr<CefBrowser> browser) OVERRIDE;
46 
47 
48     virtual bool OnProcessMessageReceived(CefRefPtr<CefBrowser> browser,
49         CefProcessId source_process,
50         CefRefPtr<CefProcessMessage> message);
51 
52 
53     bool IsClosing() const { return m_bIsClosing; }
54 
55     CefRefPtr<CefBrowser> GetBrowser(){return m_Browser;} 
56 
57 protected:
58 
59     CefRefPtr<CefBrowser> m_Browser; 
60 
61     bool m_bIsClosing;
62 
63     CMainFrameWnd*      m_pMainWnd;
64 
65     IMPLEMENT_REFCOUNTING(CCefBrowserEventHandler);
66     //由於CEF采用多線程架構，有必要使用鎖和閉包來保證在多不同線程安全的傳遞數據。IMPLEMENT_LOCKING定義提供了Lock()和Unlock()方法以及AutoLock對象來保證不同代碼塊同步訪問
67     IMPLEMENT_LOCKING(CCefBrowserEventHandler);//必須包含#include "include/base/cef_lock.h" 
68 };
69 
70 #endif//_CEFBROWSEREVENTHANDLER_H_

.cpp

  1 #include "CefBrowserEventHandler.h"
  2 #include "stdafx.h"
  3 #include <sstream>
  4 #include <string>
  5 #include "include/cef_app.h"
  6 #include "include/wrapper/cef_closure_task.h"
  7 #include "include/wrapper/cef_helpers.h"
  8 #include "MainFrameWnd.h"
  9 
 10 
 11 CCefBrowserEventHandler::CCefBrowserEventHandler(CMainFrameWnd* pMainFrame)
 12     :m_bIsClosing(false)
 13     ,m_pMainWnd(pMainFrame)
 14 {
 15 
 16 }
 17 
 18 CCefBrowserEventHandler::~CCefBrowserEventHandler()
 19 {
 20 
 21 }
 22 
 23 CefRefPtr<CefDisplayHandler> CCefBrowserEventHandler::GetDisplayHandler()
 24 {
 25     return this;
 26 }
 27 
 28 CefRefPtr<CefLifeSpanHandler> CCefBrowserEventHandler::GetLifeSpanHandler()
 29 {
 30     return this;
 31 }
 32 
 33 CefRefPtr<CefLoadHandler> CCefBrowserEventHandler::GetLoadHandler() 
 34 {
 35     return this;
 36 }
 37 
 38 void CCefBrowserEventHandler::OnTitleChange(CefRefPtr<CefBrowser> browser, const CefString& title) 
 39 {
 40     
 41 }
 42 
 43 void CCefBrowserEventHandler::OnLoadError(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, ErrorCode errorCode, 
 44                                           const CefString& errorText, const CefString& failedUrl) 
 45 {
 46     CEF_REQUIRE_UI_THREAD();
 47     if (ERR_ABORTED == errorCode)
 48         return ;
 49 
 50     std::stringstream ss;
 51     ss <<    "<html><body bgcolor=\"white\">"
 52             "<h2>Failed to load URL " << std::string(failedUrl) <<
 53             " with error " << std::string(errorText) << " (" << errorCode <<
 54             ").</h2></body></html>";
 55     frame->LoadString(ss.str(), failedUrl);
 56 }
 57 
 58 void CCefBrowserEventHandler::OnAfterCreated(CefRefPtr<CefBrowser> browser) 
 59 {
 60     CEF_REQUIRE_UI_THREAD();
 61 
 62     //base::AutoLock lock_scope(lock_);
 63 
 64     AutoLock lock_scope(this);
 65 
 66      m_Browser = browser;
 67 
 68 }
 69 
 70 bool CCefBrowserEventHandler::DoClose(CefRefPtr<CefBrowser> browser)
 71 {
 72     CEF_REQUIRE_UI_THREAD();
 73 
 74     //base::AutoLock lock_scope(lock_);
 75     AutoLock lock_scope(this);
 76 
 77 
 78     if(m_Browser) 
 79     {
 80         // Set a flag to indicate that the window close should be allowed.
 81         m_bIsClosing = true;
 82     }
 83 
 84     return false;
 85 }
 86 
 87 void CCefBrowserEventHandler::OnBeforeClose(CefRefPtr<CefBrowser> browser) 
 88 {
 89     CEF_REQUIRE_UI_THREAD();
 90 
 91     //base::AutoLock lock_scope(lock_);
 92     AutoLock lock_scope(this);
 93 
 94     if(m_Browser->IsSame(browser))  
 95         m_Browser = NULL;
 96 }
 97 
 98 bool CCefBrowserEventHandler::OnProcessMessageReceived(CefRefPtr<CefBrowser> browser,
 99                                       CefProcessId source_process,
100                                       CefRefPtr<CefProcessMessage> message) 
101 {
102     const std::string& messageName = message->GetName();
103     if (messageName == "login_msg") 
104     {   
105         // extract message
106         CefRefPtr<CefListValue> args = message->GetArgumentList();
107         CefString strUser = args->GetString(0);
108         CefString strPassword = args->GetString(1);
109 
110         m_pMainWnd->CEFLoginJsCallCPP(strUser,strPassword);//窗口類的成員函數
111 
112                 //如果函數有返回值也可以通過向Render發送消息傳遞
113         //send reply to render process
114         CefRefPtr<CefProcessMessage> outMsg = CefProcessMessage::Create("login_reply");
115 
116         // Retrieve the argument list object.
117         CefRefPtr<CefListValue> replyArgs = outMsg->GetArgumentList();
118 
119         // Populate the argument values.
120         replyArgs->SetSize(1);
121         replyArgs->SetInt(0, 0);
122 
123         // Send the process message to the renderer process.
124         browser->SendProcessMessage(PID_RENDERER, outMsg);
125 
126         return true;
127     }
128 
129     return false;
130 }

Browser進程處理完后向Render進程發了消息，The render process receives the IPC message處理

 1 #ifndef _CEFBROWSERAPP_H_
 2 #define _CEFBROWSERAPP_H_
 3 #include "include/cef_app.h"
 4 #include "CEFV8HandlerEx.h"
 5 
 6 class CCefBrowserApp
 7     : public CefApp
 8     , public CefBrowserProcessHandler
 9     , public CefRenderProcessHandler
10 {
11 public:
12     CCefBrowserApp();
13 
14     virtual ~CCefBrowserApp();
15 
16 public:
17     virtual CefRefPtr<CefBrowserProcessHandler> GetBrowserProcessHandler()OVERRIDE { return this; };
18 
19 public:
20     // CefBrowserProcessHandler methods:
21     virtual void OnContextInitialized();
22 
23     //CefRenderProcessHandler methods
24     virtual void OnWebKitInitialized();
25 
26     CefRefPtr<CefRenderProcessHandler> GetRenderProcessHandler() OVERRIDE{ return this; }
27 
28     virtual void OnContextCreated(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);
29 
30     virtual void OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context);
31 
32     //收消息
33     virtual bool OnProcessMessageReceived(CefRefPtr<CefBrowser> browser, CefProcessId source_process, CefRefPtr<CefProcessMessage> message);
34 
35 protected:
36 
37     CefRefPtr<CCEFV8HandlerEx> m_v8Handler;
38 
39     IMPLEMENT_REFCOUNTING(CCefBrowserApp);
40 };
41 #endif //_CEFBROWSERAPP_H_

.cpp

 1 #include "CefBrowserApp.h"
 2 #include "stdafx.h"
 3 
 4 
 5 CCefBrowserApp::CCefBrowserApp()
 6     :m_v8Handler(new CCEFV8HandlerEx)
 7 {
 8 }
 9 
10 CCefBrowserApp::~CCefBrowserApp()
11 {
12 }
13 
14 
15 void CCefBrowserApp::OnContextInitialized()
16 {
17     // do nothing here, because we will create browser in my own dialog
18 }
19 
20 void CCefBrowserApp::OnContextCreated(CefRefPtr<CefBrowser> browser,
21                               CefRefPtr<CefFrame> frame,
22                               CefRefPtr<CefV8Context> context)
23 {
24     // Retrieve the context's window object.
25     CefRefPtr<CefV8Value> object = context->GetGlobal();
26 
27     // Create the "NativeLogin" function.
28     CefRefPtr<CefV8Value> func = CefV8Value::CreateFunction("NativeLogin", m_v8Handler);//第一個參數和SetValue參數保持一致,否則無法調用
29 
30     // Add the "NativeLogin" function to the "window" object.
31     object->SetValue("NativeLogin", func, V8_PROPERTY_ATTRIBUTE_NONE);
32 
33     // Add the "register" function to the "window" object.
34     object->SetValue("register",CefV8Value::CreateFunction("register", m_v8Handler),V8_PROPERTY_ATTRIBUTE_NONE);
35 }
36 
37 void CCefBrowserApp::OnWebKitInitialized()
38 {
39     std::string app_code =
40         "var app;"
41         "if (!app)"
42         "    app = {};"
43         "(function() {"
44         "    app.GetId = function() {"
45         "        native function GetId();"
46         "        return GetId();"
47         "    };"
48         "})();";
49 
50     // Registered Javascript Function, which will be called by Cpp
51     "  app.registerJavascriptFunction = function(name,callback) {"
52         "    native function registerJavascriptFunction();"
53         "    return registerJavascriptFunction(name,callback);"
54         "  };"
55 
56         "})();";
57 
58 
59     CefRegisterExtension("v8/app", app_code, m_v8Handler);//第一個參數不能為空
60 }
61 
62 void CCefBrowserApp::OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context)
63 {
64     m_v8Handler = nullptr;
65 }
66 
67 bool CCefBrowserApp::OnProcessMessageReceived(CefRefPtr<CefBrowser> browser,CefProcessId source_process,CefRefPtr<CefProcessMessage> message) 
68 {
69     const std::string& messageName = message->GetName();
70     if (messageName == "login_reply")
71     {
72         // extract message
73         CefRefPtr<CefListValue> args = message->GetArgumentList();
74         bool status = args->GetBool(0);
75 
76         CefRefPtr<CefFrame> frame = browser->GetMainFrame();
77 
78         if (status)
79         {
80             frame->ExecuteJavaScript("IsSuccess();", frame->GetURL(), 0);
81         }
82         
83         return true;
84     }
85 
86     return false;
87 }

2.JS CallBack

在OnContextCreated()函數中給window綁定函數

1 // Create the "register" function.
2     CefRefPtr<CefV8Value> func = CefV8Value::CreateFunction("register", m_v8Handler);//第一個參數和SetValue參數保持一致,否則無法調用
3 
4 // Add the "register" function to the "window" object.
5     object->SetValue("register", func, V8_PROPERTY_ATTRIBUTE_NONE);

在Exectue()函數中處理

else if (name == "register")
{
    if (arguments.size() == 1 && arguments[0]->IsFunction()) 
    {
        CefRefPtr<CefV8Value> callback_func_ = arguments[0];
        CefRefPtr<CefV8Context> callback_context_ = CefV8Context::GetCurrentContext();

        callback_func_->ExecuteFunction(NULL, arguments);//執行回調函數

        return true;
    }
}

在HTML的JavaScript里這樣寫

  function myFunc() 
{
     // do something in JS.
      alert("callback");
}
      
//js CALLback
function CallBack()
{
     window.register(myFunc);
}

3.C++ 調用 JS

C++調用JS函數相對簡單多了，因為CEF有接口可以直接使用CefFrame::ExecuteJavaScript，看看注釋:

 1  ///
 2   // Execute a string of JavaScript code in this frame. The |script_url|
 3   // parameter is the URL where the script in question can be found, if any.
 4   // The renderer may request this URL to show the developer the source of the
 5   // error.  The |start_line| parameter is the base line number to use for error
 6   // reporting.
 7   ///
 8   /*--cef(optional_param=script_url)--*/
 9   virtual void ExecuteJavaScript(const CefString& code,
10                                  const CefString& script_url,
11                                  int start_line) =0;

首先需要獲取到我們的瀏覽器里的主框架對象，code是JS函數和傳入參數的字符串，URL可以直接忽略。

1 CefRefPtr<CefFrame> frame = m_handler->GetBrowser()->GetMainFrame();
2 
3 m_handler是我們自己定義的Handler對象
4 
5 /C++ 調用js方法
6 //frame->ExecuteJavaScript(L"Test();",frame->GetURL(),0);//提示框
7 //frame->ExecuteJavaScript(L"ModifyValue();",frame->GetURL(),0);//無參數函數
8 frame->ExecuteJavaScript(L"ModifyValue('巴薩牛逼');",frame->GetURL(),0);//有參數函數
9 如果參數是可變的，可以這樣

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

其中setInstallStatus是js函數，它有三個參數

我在HMTL里寫的

  function Test()
{
     alert("js被C++非禮了");
}
      
 function ModifyValue( arr)
{
      //document.getElementById("text").innerHTML = "被修改了";
       
    alert(arr);
     document.getElementById("text").innerHTML = arr;
 }

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