目前網卡有10M,100M,1G這三種，我應該用哪些ＡＰＩ來得知目前連線狀況？ http://delphi.ktop.com.tw/topic.php?topic_id=22757 裡面有提到大概做法，不過還是不太懂，如何使用setup API來OPEN device. 網上也找不到範例，目前自己做到如下步驟，卻不知如何接下去或有無錯誤之處，不知哪位可以替我指點迷津。Thanks.  

    GUID *guidList;
HDEVINFO  DevInfoSet;
DWORD  MemberIndex;
SP_DEVINFO_DATA  *DevInfoData;
DWORD  ReqSize;
bool Return;
int index;
//------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
        ReqSize = 1;
        guidList = new GUID[ReqSize];
        DevInfoData = new SP_DEVINFO_DATA;
        DevInfoData->cbSize = sizeof(SP_DEVINFO_DATA);            Return = SetupDiClassGuidsFromName(
                        "Net",
                        guidList,
                        ReqSize,
                        &ReqSize);
        if(Return == False){
                delete [] guidList;
                guidList = new GUID[ReqSize];
                SetupDiClassGuidsFromName(
                        "Net",
                        guidList,
                        ReqSize,
                        &ReqSize);
        }            DevInfoSet = SetupDiGetClassDevs(
                        guidList,
                        NULL,
                        NULL,
                        DIGCF_PRESENT);            index = 0;
        do{
                Return = SetupDiEnumDeviceInfo(
                                DevInfoSet,
                                index,
                                DevInfoData);                    if(Return) {
                        Memo1->Lines->Add("OK");
                }
                else {
                        Memo1->Lines->Add(IntToStr(GetLastError()));
                }                    index   ;
        }while(Return);            delete [] guidList;
        delete [] DevInfoData;
}     

最近我加入一個API=>SetupDiGetDeviceRegistryProperty結果卻出現 The data is invalid. 的LastError不知道原因出在哪.寫法如下  

BYTE  *PropertyBuffer;
DWORD type;    PropertyBuffer = new BYTE[256];    Return = SetupDiGetDeviceRegistryProperty(
                                DevInfoSet,
                                DevInfoData,         
                                SPDRP_FRIENDLYNAME,    
                                &type,                 
                                PropertyBuffer,     
                                256,               
                                NULL);                              if(Return) {
                        Memo1->Lines->Add("OK");
                }
                else {
                        Memo1->Lines->Add(IntToStr(GetLastError()));
                }
 

有人看的出其中錯誤的地方嗎?Thanks.