Export (0) Print
Expand All

CComSafeArray Class

This class is a wrapper for the SAFEARRAY structure.

template <
   typename T,
   VARTYPE _vartype = _ATL_AutomationType< T >::type
>
class CComSafeArray

T

The type of data to be stored in the array.

CComSafeArray provides a wrapper for the SAFEARRAY Data Type class, making it a simple matter to create and manage single- and multidimensional arrays of almost any of the VARIANT-supported types.

CComSafeArray simplifies passing arrays between processes, and in addition provides extra security by checking array index values against upper and lower bounds.

The lower bound of a CComSafeArray can start at any user-defined value; however, arrays that are accessed through C++ should use a lower bound of 0. Other languages such as Visual Basic may use other bounding values (for example, -10 to 10).

Use CComSafeArray::Create to create a CComSafeArray object, and CComSafeArray::Destroy to delete it.

A CComSafeArray can contain the following subset of VARIANT data types:

VARTYPE

Description

VT_I1

char

VT_I2

short

VT_I4

int

VT_I4

long

VT_I8

longlong

VT_UI1

byte

VT_UI2

ushort

VT_UI4

uint

VT_UI4

ulong

VT_UI8

ulonglong

VT_R4

float

VT_R8

double

VT_DECIMAL

decimal pointer

VT_VARIANT

variant pointer

VT_CY

Currency data type

Header: atlsafe.h

// Create a multidimensional array,  
// then write and read elements 

// Define an array of character pointers
CComSafeArray<char> *pSar;

char cElement;
char cTable[2][3] = {'A','B','C','D','E','F'};

// Declare the variable used to store the 
// array indexes
LONG aIndex[2];

// Define the array bound structure
CComSafeArrayBound bound[2];
bound[0].SetCount(3);
bound[0].SetLowerBound(0);
bound[1].SetCount(3);
bound[1].SetLowerBound(0);   

// Create a new 2 dimensional array 
// each dimension size is 3
pSar = new CComSafeArray<char>(bound,2); 

// Use MultiDimSetAt to store characters in the array 
for (int x = 0; x < 2; x++)
{
   for (int y = 0; y < 3; y++)
   {
      aIndex[0] = x;
      aIndex[1] = y;
      HRESULT hr = pSar->MultiDimSetAt(aIndex,cTable[x][y]);
      ATLASSERT(hr == S_OK);
   }
}
// Use MultiDimGetAt to retrieve characters in the array 
for (int x = 0; x < 2; x++)
{
   for (int y = 0; y < 3; y++)
   {
      aIndex[0]=x;
      aIndex[1]=y;
      HRESULT hr = pSar->MultiDimGetAt(aIndex,cElement);
      ATLASSERT(hr == S_OK);
      ATLASSERT(cElement == cTable[x][y]);
   }   
}

Only the following VARTYPEs are fully supported: VT_BSTR, VT_VARIANT, VT_UNKNOWN, and VT_DISPATCH.

Community Additions

ADD
Show:
© 2014 Microsoft