VC++ 项目中应用 FLEX

VC++ 项目中使用 FLEX

Here, each individual cells in the ADG are editable. You can type in any Excel formula into it and hit the "Compute" button. The application invokes Excel using COM, computes the results and populates the result into the ADG.

Scan images right into flexbook:

When the Scan button is clicked, a TWAIN dialog pops up letting you use your scanner to scan images directly into the pages of the flexbook component.

Sample app showing two flash player instances each with a flex application:

The bridge supports multiple flash player instances. It can talk to each instance in a different manner. If you look at the screenshot, both the instances are loading the same swf file. But the C++ code for one instance adds a datagrid and removes an element shown in the pie chart.

How does it work?

The flash player ActiveX control is added to a MFC dialog. Now the content in the flash player can talk to the C++ application via ExternalInterface. ExternalInterface.call("fnname") will dispatch a FlashCall message on the C++ side which will have the arguments passed to call() in XML. This XML has to be parsed to understand what the message was from the actionscript side.

All this complexity is hidden by the bridge. The bridge talks with the actionscript side of Ely's FABridge and facilitates calling and referencing to actionscript objects, classes and methods.

There are multiple worker threads waiting to process incoming or outgoing flash requests so that the main MFC thread does not block. The bridge can even support multiple flash player instances each with it's own bridge back to the C++ application.

Also, Actionscript exceptions are serialized and thrown on the C++ side.

C++ Syntax Rules

To start off, you need the root object which is the main application object of your flex application. Now you can access the public methods and properties of your application.

Getters and setters are treated differently: A property "width" will be translated to "getwidth" for retrieving the value and "setwidth" for setting the value. Ely's FABridge had camel casing here, but that has been removed so that constants like MOUSE_DOWN don't confuse the bridge.

The "Call" method shown in the snippets above take a string as the first argument that is the name of the method or property (suitably modified using above defined rules) and the arguments for it. Common types like string, int, reference to an AS object, custom anonymous AS object etc are converted internally to an ASObject thanks to copy constructors and operator overloads.

For more examples of the syntax, take a look at the Worker() method in?
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首先，需要在项目中嵌入Flash player插件，网上有很多例子。另外Flex也要写好代码，这里略掉。
添加一个ExternalInterface的事件处理函数，对于Flash player来讲就是FlashCall事件（跟FSCommand不同的），这里的事件处理函数是void CMyBicapDlg::OnFlashCallShockwaveflash1(LPCTSTR request)。没有返回值（下面会讲到），参数是一个XML格式的字符串。格式是"<invoke name='%s' returntype='xml'><arguments><string>%s</string></arguments></invoke>"，去查查帮助就知道了。
处理request：标准C++没有处理XML的库，我去下载了tinyxml，小巧好用。下面就是按照个人需要处理request了，我这里是，打开一个文件夹选择对话框然后选择一个路径。
返回值。事件处理函数是没有返回值的，但是flash player提供了一个方法：m_FlashPlayer.SetReturnValue(re_value.c_str());，专门传递返回值，格式是<string>%s</string>（也可以是别的AS结构，具体看帮助）。
需要提醒的是，在处理期间要block掉Flex，ExternalInterface.call是有返回值的，如果不阻塞Flex，可能返回就是NULL，呵呵，不知道深层原因。另外，反过来调用格式也是一样的。
调试环境：win xp, VC++6.0, Flex builder 2.0