c++ - 如何将类方法转换为 QScriptEngine::FunctionSignature

Question

我想通过这个方法:

QScriptValue ScriptProcessContext::construct(QScriptContext * ctx, QScriptEngine *)
{
    return this->newInstance();
}

到QScriptEngine::newFunction .我尝试了以下选项:

• 如文档中所示 and also this example code :

  QScriptValue ctor = engine->newFunction(construct);
  

  错误:

  error C3867: 'ScriptProcessContext::construct': function call missing argument list; use '&ScriptProcessContext::construct' to create a pointer to member
  

• 强制转换:

  QScriptValue ctor = engine->newFunction((QScriptEngine::FunctionSignature)construct);
  

  错误:

  error C2440: 'type cast' : cannot convert from 'overloaded-function' to 'QScriptEngine::FunctionSignature'
  

• 将指针转换为成员

  QScriptValue ctor = engine->newFunction(
     (QScriptValue(ScriptProcessContext::*)(QScriptContext *, QScriptEngine *))
      &ScriptProcessContext::construct
  );
  

  错误:

   error C2664: 'QScriptValue QScriptEngine::newFunction(QScriptEngine::FunctionSignature,int)' : cannot convert parameter 1 from 'QScriptValue (__cdecl ScriptProcessContext::* )(QScriptContext *,QScriptEngine *)' to 'QScriptEngine::FunctionSignature'
  

那么怎么写才是正确的呢？

Answer 1

您尝试传递一个成员函数。那是不支持的。使用自由函数或静态方法。

请注意，在这两种情况下，您都没有 this 指针。您需要以不需要对象的方式编写函数。