// Converts a string to a PropVariant with type LPWSTR instead of BSTR
// The resulting variant must be cleared using PropVariantClear and freed using Marshal.FreeCoTaskMem
public static IntPtr PropVariantFromString(string value)
{
IntPtr pstr = IntPtr.Zero;
IntPtr pv = IntPtr.Zero;
try
{
// In managed code, new automatically zeros the contents.
PropVariant.PROPVARIANT propvariant = new PropVariant.PROPVARIANT();
// Allocate the string
pstr = Marshal.StringToCoTaskMemUni(value);
// Allocate the PropVariant
pv = Marshal.AllocCoTaskMem(16);
// Transfer ownership of the string
propvariant.vt = 31; // VT_LPWSTR - not documented but this is to be allocated using CoTaskMemAlloc.
propvariant.dataIntPtr = pstr;
Marshal.StructureToPtr(propvariant, pv, false);
pstr = IntPtr.Zero;
// Transfer ownership to the result
IntPtr result = pv;
pv = IntPtr.Zero;
return(result);
}
finally
{
if (pstr != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(pstr);
pstr = IntPtr.Zero;
}
if (pv != IntPtr.Zero)
{
try
{
NativeMethods.PropVariantClear(pv);
}
catch
{
Debug.Fail("VariantClear failure");
}
Marshal.FreeCoTaskMem(pv);
pv = IntPtr.Zero;
}
}
}
// Converts a string to a PropVariant with type LPWSTR instead of BSTR
// The resulting variant must be cleared using PropVariantClear and freed using Marshal.FreeCoTaskMem
public static IntPtr PropVariantFromString(string value)
{
IntPtr pstr = IntPtr.Zero;
IntPtr pv = IntPtr.Zero;
try
{
// In managed code, new automatically zeros the contents.
PropVariant.PROPVARIANT propvariant = new PropVariant.PROPVARIANT();
// Allocate the string
pstr = Marshal.StringToCoTaskMemUni(value);
// Allocate the PropVariant
pv = Marshal.AllocCoTaskMem(16);
// Transfer ownership of the string
propvariant.vt = 31; // VT_LPWSTR - not documented but this is to be allocated using CoTaskMemAlloc.
propvariant.dataIntPtr = pstr;
Marshal.StructureToPtr(propvariant, pv, false);
pstr = IntPtr.Zero;
// Transfer ownership to the result
IntPtr result = pv;
pv = IntPtr.Zero;
return result;
}
finally
{
if (pstr != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(pstr);
pstr = IntPtr.Zero;
}
if (pv != IntPtr.Zero)
{
try
{
NativeMethods.PropVariantClear(pv);
}
catch
{
Debug.Fail("VariantClear failure");
}
Marshal.FreeCoTaskMem(pv);
pv = IntPtr.Zero;
}
}
}
