DCEF3 - Delphi Chromium Embedded - communication b

问题:

I'm using DCEF3, revision 24038bd3a600, and I should want to communicate between Javascript code in browser and Delphi code of application. I know how it can be accomplished from Delphi code and Javascript, by using framework's method 'ExecuteJavascript', but what about the reverse (from Javascript to Delphi/application code) ? I haven't found such a situation in demos/examples (GUIclient, specifically...).

回答1:

There is a guiclient demo if official source code to do this. Look at main.pas file.

The code below is a class extension :

class function TTestExtension.hello: string;
begin
  Result := 'Hello from Delphi';
end;

The code below register the extension class :

TCefRTTIExtension.Register('app', TTestExtension);

The code below call your native code from a HTML page :

<script>
alert ( app.hello() );
</script>

The code below call your native code from embedded browser :

crm.Browser.MainFrame.ExecuteJavaScript('alert ( app.hello() );', 'about:blank', 0);

回答2:

A quite easy workaround is to catch the browser's OnJSDialog / OnConsoleMessage event, do an Alert/log in JS when there's something to execute. Tell the delphi part in the alert's message what to do. You need to interpret it as a string (maybe with a scripting library or direct parsing). No direct call of delphi code is possible with it, but I guess it's safer this way anyway.