SafeArray数据

SafeArrayCreateVector()

2025-01-19

Written by: tdtc

Recommendation: Starting October 14, 2025, do not use ATL or MFC in new projects.

!!! 除了IE的ActiveX项目，不推荐ATL !!!
!!! ATL is not recommended except for IE ActiveX projects. !!!

COM

vc

1. 定义SAFEARRAY变量

SAFEARRAY *pSArray = NULL;

2. 释放此变量

SafeArrayDestroy(pSArray);

3. 建立向量表

pSArray = SafeArrayCreateVector(VT_UI1, 0, 32);

向量变量(VT_UI1)

• Definition in wtypes.h

typedef unsigned short VARTYPE;
/*
 * VARENUM usage key,
 *
 * * [V] - may appear in a VARIANT
 * * [T] - may appear in a TYPEDESC
 * * [P] - may appear in an OLE property set
 * * [S] - may appear in a Safe Array
 */
typedef enum VARENUM {
//...
  VT_UI1 = 17,
//...
} ;

• Constants

VT_UI1
Variable type is unsigned char.

4. 写入数据

SafeArrayPutElement(pSArray, &l, &inqReport[l]);

getInqRepo方法：

AA：屏蔽的数值

STDMETHODIMP CRepoFmt::getInqRepo(ULONG iStation, SAFEARRAY** ret)
{
	SAFEARRAY *pSArray = NULL;

	unsigned char inqReport[32];
	unsigned char xorByte = AA;
	int iStationID = 0;

	if (iStation < 1)
		iStationID = 1;
	else
		iStationID = iStation;

	inqReport[0]  = AA;
	inqReport[1]  = AA;
	inqReport[2]  = AA;
	inqReport[3]  = AA;
	inqReport[4]  = (iStationID % AA);
	inqReport[5]  = (iStationID / AA);
	inqReport[6]  = AA;
	inqReport[7]  = AA;
	inqReport[8]  = AA;
	inqReport[9]  = AA;
	inqReport[10] = AA;
	inqReport[11] = AA;

	for (int i = 1; i < 18; i++)
		xorByte ^= inqReport[i];

	inqReport[18] = xorByte;

	// Fill the inqReport etc.
	for (int j = 12; j < 18; j++)
		inqReport[j] = 0;
	for (int k = 19; k < 32; k++)
		inqReport[k] = 0;

	if (!ret)
		return E_POINTER;

	if (*ret) {
		SafeArrayDestroy(pSArray);
		*ret = NULL;
	}

	pSArray = SafeArrayCreateVector(VT_UI1, 0, 32);
	for (long l = 0; l < 32; l++)
		SafeArrayPutElement(pSArray, &l, &inqReport[l]);

	*ret = pSArray;

	return S_OK;
}

调用COM

c#的按钮事件

// clear TextBox
edtAck.Text = "";
edtInq.Text = "";

repoInfoLib.RepoFmtClass report = new RepoFmtClass();
Array retAck = report.getAckRepo((uint)Int32.Parse(edtStation.Text));

foreach (Byte bt in retAck)
    edtAck.Text += "0x" + bt.ToString("X2") + " ";

Array retInq = report.getInqRepo((uint)Int32.Parse(edtStation.Text));

foreach (Byte bt in retInq)
    edtInq.Text += "0x" + bt.ToString("X2") + " ";

• 建立COM实例

第5行

• 调用COM方法

第6, 10行
此方法返回SafeArray数据

• 赋值

第8，9行和第12，13行
把每个数组中的数据赋值给TextBox控件，并以十六进制方式显示（0xYY）。