《XPCOM组件开发》笔记（四）

通用型XPCOM模块宏

宏<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />	作用
NS_IMPL_NSGETMODULE(name, components)	实现IModule接口
NS_IMPL_NSGETMODULE_WITH_CTOR(name, components, ctor)	同上，但允许指定模块创建时调用一个特定函数
NS_IMPL_NSGETMODULE_WITH_DTOR (name, components, dtor)	同第一个，但允许指定模块销毁时调用一个特定函数
NS_IMPL_NSGETMODULE_WITH_CTOR_DTOR (name, components, ctor, dtor)	结合2，3

模块实现宏：

nsModuleComponentInfo结构体包含4个域：1）给人读的类名称 2）类ID(CID) 3)契约ID 4)用于给定对象的构造者

staticconstnsModuleComponentInfocomponents[]=
{
{"PrettyClassName",
CID,
CONTRACT_ID,
Constructor
},
.
}

工厂宏：

NS_GENERIC_FACTORY_CONSTRUCTOR(ConcreteClass)

常用实现宏

NS_IMPL_ISUPPORTS1(classname,interface1)
NS_IMPL_ISUPPORTSn(classname,interface1,…,interfacen)

声明宏：

classmyEnumerator:publicnsISimpleEnumerator
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSISIMPLEENUMERATOR
myEnumerator();
virtual~myEnumerator(){}
};

NS_IMPL_ISUPPORTSn	为指定类实现nsISupports，此类有n个接口
NS_DECL_ISUPPORTS	声明ISuppotrs接口的方法，包含mRefCnt
NS_INIT_ISUPPORTS	初始化mRefCnt为0
NS_GET_IID	返回给定接口名称的IID

智能指针

{
nsCOMPtr<nsISupports>value;
object->method(getter_AddRefs(value));
if(!value)return;

if(NS_FAILED(error))
return;

}

SomeClass::Get(nsISupports**aResult)
{
if(!aResult)
returnNS_ERROR_NULL_POINTER;
nsCOMPtr<nsISupports>value;
object->method(getter_AddRefs(value));
*aResult=value.get();
NS_IF_ADDREF(*aResult);
returnNS_OK;
}

示例：

#include"nsIGenericFactory.h"
#defineSAMPLE_CID/
{0x777f7150,0x4a2b,0x4301,/
{0xad,0x10,0x5e,0xab,0x25,0xb3,0x22,0xaa}}
classSample:publicnsISupports
{
public:
Sample();
virtual~Sample();
NS_DECL_ISUPPORTS
};
Sample::Sample()
{
//note:innewerversionsofGecko(1.3orlater)
//youdon’thavetodothis:
NS_INIT_ISUPPORTS();
}
Sample::~Sample()
{
}
NS_IMPL_ISUPPORTS(Sample,nsISupports);
NS_GENERIC_FACTORY_CONSTRUCTOR(Sample);

staticconstnsModuleComponentInfocomponents[]=
{
{"PrettyClassName",
SAMPLE_CID,
"@company.com/sample"
SampleConstructor
}
};
NS_IMPL_NSGETMODULE(nsSampleModule,components)