SafeArrayAccessData

项目
06/30/2006

This function increments the lock count of an array, and retrieves a pointer to the array data.

HRESULT SafeArrayAccessData( 
  SAFEARRAY FAR* psa, 
  void HUGEP* FAR* ppvData 
);

Parameters

psa
[in] Pointer to an array descriptor created by SafeArrayCreate.
ppvData
[in] On exit, pointer to a pointer to the array data.

Return Values

The following table shows the HRESULT values that can be returned by this function.

Value	Description
S_OK	Success.
E_INVALIDARG	The psa parameter was not a valid safearray descriptor.
E_UNEXPECTED	The array could not be locked.

Remarks

Passing invalid (and under some circumstances NULL) pointers to this function causes an unexpected termination of the application.

Example

The following code example sorts a safearray of one dimension that contains BSTRs by accessing the array elements directly. This approach is faster than using SafeArrayGetElement and SafeArrayPutElement.

long i, j, min; 
BSTR BSTRTemp;
BSTR HUGEP *pBSTR;
HRESULT hr;

// Get a pointer to the elements of the array.
hr = SafeArrayAccessData(psa, (void HUGEP* FAR*)&pBSTR);
if (FAILED(hr))
goto error;

// Bubble sort.
cElements = lUBound–lLBound+1; 
for (i = 0; i < cElements–1; i++)
{
  min = i;
  for (j = i+1; j < cElements; j++)
  {
    if (wcscmp(pBSTR[j], pBSTR[min]) < 0)
      min = j; 
  }

  // Swap array[min] and array[i].
  BSTRTemp = pBSTR[min];
  pBSTR[min] = pBSTR[i];
  pBSTR[i] = BSTRTemp;

}

SafeArrayUnaccessData(psa);

Requirements

OS Versions: Windows CE 2.0 and later.
Header: Oleauto.h.
Link Library: Oleaut32.lib.

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