AngelScript作為一個(gè)嵌入式的腳本庫(kù)不支持獨(dú)立運(yùn)作(原文: Being an embedded scripting library there isn't much that AngelScript allows the scripts to do by themselves,)，       因此，應(yīng)用程序必須先注冊(cè)一個(gè)接口讓腳本與應(yīng)用程序交互（原文:so the first thing the application must do is to register the interface that the script will have to interact with the application.）。該接口可以由函數(shù)、變量、甚至是一個(gè)完整的類組成（原文:The interface may consist of functions, variables, and even complete classes.）。

// 創(chuàng)建一個(gè)腳本引擎

asIScriptEngine *engine = asCreateScriptEngine(ANGELSCRIPT_VERSION);

// 設(shè)置一個(gè)消息回調(diào)來(lái)接收可讀的錯(cuò)誤信息

// 建議在創(chuàng)建一個(gè)引擎對(duì)象后這樣做一下, 因?yàn)槿绻?cè)失敗，本引擎可以發(fā)送一些有效信息到消息流中

r = engine->SetMessageCallback(asFUNCTION(MessageCallback), 0, asCALL_CDECL); assert( r >= 0 );

//由于標(biāo)準(zhǔn)的C++中沒有明確的字符串類型，因此，AngelScript也沒有內(nèi)置的字符串類型.

//故每個(gè)開發(fā)人員可以自由注冊(cè)它自己的字符串類型

//但是本引擎SDK為注冊(cè)一個(gè)字符串類型提供了一個(gè)標(biāo)準(zhǔn)的附加項(xiàng)，因此如果你不想注冊(cè)，就沒有必要進(jìn)行注冊(cè)  

RegisterStdString(engine);

// 注冊(cè)一個(gè)腳本中的函數(shù)

r = engine->RegisterGlobalFunction("void print(const string &in)", \

                                asFUNCTION(print), asCALL_CDECL); assert( r >= 0 );

       配置好引擎之后，下一步便是編譯要執(zhí)行的腳本了（原文:After the engine has been configured, the next step is to compile the scripts that should be executed.）。接下來(lái)是一個(gè)注冊(cè)print函數(shù)將“Hello world”寫在標(biāo)準(zhǔn)輸出流中。例如，下面test.as文件中存儲(chǔ)的代碼（原文: The following is our script that will call the registered print function to write Hello world on the standard output stream. Let's say it's stored in the file test.as.）:

void main()

{

  print("Hello world\n");

}

       下面的代碼是加載腳本文件并編譯(Here's the code for loading the script file and compiling it. ):

// CScriptBuilder類是一個(gè)裝在文件的附加物

//如果有必要的話，通過(guò)執(zhí)行一個(gè)預(yù)處理, 然后告訴引擎組建一個(gè)腳本模塊

CScriptBuilder builder;

r = builder.BuildScriptFromFile(engine, "MyModule", "test.as");

if( r < 0 )

{

  // 產(chǎn)生一個(gè)錯(cuò)誤. 把它列在標(biāo)準(zhǔn)輸出流中以通知腳本作者修正腳本錯(cuò)誤

  printf("Please correct the errors in the script and try again.\n");

  return;

}

       最后一步是關(guān)聯(lián)要被調(diào)用的函數(shù)，并建立上下文來(lái)執(zhí)行它(原文:The last step is to identify the function that is to be called, and set up a context for executing it. )

// 定位到被調(diào)用的函數(shù)

asIScriptModule *mod = engine->GetModule("MyModule");

int funcId = mod->GetFunctionIdByDecl("void main()");

if( funcId < 0 )

{

  // 找不到這個(gè)函數(shù)(The function couldn't be found.)。

  // 通知腳本作者在腳本中包含指定的函數(shù).

  printf("The script must have the function 'void main()'. Please add it and try again.\n");

  return;

}

// 創(chuàng)建一個(gè)引擎環(huán)境, 配置一下, 然后執(zhí)行

asIScriptContext *ctx = engine->CreateContext();

ctx->Prepare(funcId);

r = ctx->Execute()

if( r != asEXECUTION_FINISHED )

{

  // The execution didn't complete as expected. 確定發(fā)生了什么.

  if( r == asEXECUTION_EXCEPTION )

  {

    // 發(fā)生一個(gè)異常, 讓腳本作者知道發(fā)生了什么，怎樣才可以修正它.

    printf("An exception '%s' occurred. Please correct the code and try again.\n", ctx->GetExceptionString());

  }

}

       上面試最基本的異常處理（原文:The exception handling above is very basic.）。如果需要，該應(yīng)用程序也可以獲得關(guān)于行號(hào)、函數(shù)、調(diào)用堆棧信息、以及本地和全局變量（原文:The application may also obtain information about line number, function, call stack, and even values of local and global variables if wanted. ）。

       在虛擬機(jī)執(zhí)行完之后，不要忘了清理一下（原文:Don't forget to clean up after you're done with the engine. ）

// 清理

ctx->Release();

engine->Release();

       Helper functions

       在print 函數(shù)是對(duì)printf函數(shù)很簡(jiǎn)單封裝（The print function is implemented as a very simple wrapper on the printf function.）。

// 打印腳本字符串到標(biāo)準(zhǔn)輸出流

void print(string &msg)

{

  printf("%s", msg.c_str());

}

另見: