将多个值放在结构的单个属性中

Question

我需要将多个值放在结构的单个属性中，将接收值的属性是 LPSTR，我试图将所有这些作为向量传递，编译，但它不起作用如我所愿。

我的结构：

typedef struct _wfs_pin_caps
{
WORD                wClass;
WORD                fwType;
............More...............
BOOL                bIDConnect;
WORD                fwIDKey;
WORD                fwValidationAlgorithms;
WORD                fwKeyCheckModes;
LPSTR               lpszExtra; //This attribute must receive more than one value 
} WFSPINCAPS, * LPWFSPINCAPS;

正如我正在尝试做的：

HRESULT WINAPI WFPGetInfo(HSERVICE hService, DWORD dwCategory, LPVOID   lpQueryDetails, DWORD dwTimeOut, HWND hWnd, REQUESTID ReqID) {

    ...

    result = WFMAllocateMore(sizeof(WFSPINCAPS), lpWFSResult, &lpWFSResult->lpBuffer);

    ...

    //This Values
    vector<LPSTR> Tokens;
        Tokens[1] = (LPSTR)"Value1";
        Tokens[2] = (LPSTR)"Value2";
        Tokens[3] = (LPSTR)"Value4";
        Tokens[4] = (LPSTR)"Value5";

        PinCapabilities.lpszExtra = (LPSTR)&Tokens; //Pass HERE

    memcpy(lpWFSResult->lpBuffer,&PinCapabilities,sizeof(WFSPINCAPS));

    ... 
return WFS_SUCCESS;

Answer 1

你的问题很不清楚，但如果我理解的话，问题是你将 lpszExtra 设置为局部向量 Tokens （存储在堆栈中）并且将在该函数的结尾。

一种方法是像这样在堆中创建向量：

// Create a new vector in the heap of 5 elements (0..4)
vector<LPSTR> &Tokens = *new vector<LPSTR>(5); 
Tokens[1] = (LPSTR) "Value1";
Tokens[2] = (LPSTR) "Value2";
Tokens[3] = (LPSTR) "Value4";
Tokens[4] = (LPSTR) "Value5";

PinCapabilities.lpszExtra = (LPSTR) &Tokens; //Pass HERE

// Assuming that lpBuffer has room for a WFSPINCAPS structure
memcpy(lpWFSResult->lpBuffer, &PinCapabilities, sizeof(WFSPINCAPS));

现在 ((LPWFSPINCAPS)lpWFSResult->lpBuffer)->lpszExtra 包含指向 vector 的有效指针，可用于任何其他函数，如下所示：

LPWFSPINCAPS pPinCapabilities = (LPWFSPINCAPS) lpWFSResult->lpBuffer;
vector<LPSTR> &Tokens = *(vector<LPSTR> *) pPinCapabilities->lpszExtra;
LPSTR str = Tokens[3]; // Will get "Value4"

但不要忘记，在某些时候你将不得不释放向量的内存：

LPWFSPINCAPS pPinCapabilities2 = (LPWFSPINCAPS) lpWFSResult->lpBuffer;
delete (vector<LPSTR> *) pPinCapabilities2->lpszExtra;

请下次尝试 create a Minimal, Complete, and Verifiable example 帮助我们帮助您。

将多个值放在结构的单个属性中

Put multiple values in a single attribute of a struct

c++

dll

struct

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