Use the variant type to pass array data in the com Method

In the com method, array data can be transmitted using the variant type and processed using safearray in VC ++. The following example shows the input and output arrays.

1. Input an array to com
Stdmethodimp ctestcom1: vb2vc (variant buffer)
{
Long dim = safearraygetdim (buffer. parray );
Long ubound;
Long lbound;

Safearraygetubound (buffer. parray, dim, & ubound );
Safearraygetlbound (buffer. parray, dim, & lbound );
BSTR * Buf;
BSTR Pd [2];
Safearrayaccessdata (buffer. parray, (void **) & BUF );
For (INT I = lbound; I <ubound; I ++)
Pd [I] = Buf [I];
}
Return s_ OK;
}

Buffer is a one-dimensional array that stores strings. The code in VB is
Dim oo as arraytestlib. testcom1
Set oo = new arraytestlib. testcom1
Dim Buf (2) as string
Buf (0) = "65"
Buf (1) = "anss"
OO. vb2vc Buf

2. Com returns array data to VB

Stdmethodimp ctestcom1: retarray (variant * buffer)
{
// Returns an array.
Safearray far * PSA;
Safearraybound rgsabound [1];
Rgsabound [0]. llbound = 0;
Rgsabound [0]. celements = 2;
PSA = safearraycreate (vt_i4, 1, rgsabound );

Long idx;
Long setdt;

Idx = 0;
Setdt = 12;

Safearrayputelement (PSA, & idx, & setdt );
Idx = 1;
Set setdt = 342;
Safearrayputelement (PSA, & idx, & setdt );

V_vt (buffer) = vt_array | vt_i4;
V_array (buffer) = psa;

Return s_ OK;
}

The code in VB is:
Dim oo as arraytestlib. testcom1
Set oo = new arraytestlib. testcom1
Dim rarr as Variant
OO. retarray rarr
Msgbox rarr (0) & rarr (1)