/// <summary>
/// Enumerates product installations based on certain criteria.
/// </summary>
/// <param name="productCode">ProductCode (GUID) of the product instances to be enumerated. Only
/// instances of products within the scope of the context specified by the
/// <paramref name="userSid"/> and <paramref name="context"/> parameters will be
/// enumerated. This parameter may be set to null to enumerate all products in the specified
/// context.</param>
/// <param name="userSid">Specifies a security identifier (SID) that restricts the context
/// of enumeration. A SID value other than s-1-1-0 is considered a user SID and restricts
/// enumeration to the current user or any user in the system. The special SID string
/// s-1-1-0 (Everyone) specifies enumeration across all users in the system. This parameter
/// can be set to null to restrict the enumeration scope to the current user. When
/// <paramref name="context"/> is set to the machine context only,
/// <paramref name="userSid"/> must be null.</param>
/// <param name="context">Specifies the user context.</param>
/// <returns>An enumeration of product objects for enumerated product instances.</returns>
/// <remarks><p>
/// Win32 MSI API:
/// <a href="http://msdn.microsoft.com/library/en-us/msi/setup/msienumproductsex.asp">MsiEnumProductsEx</a>
/// </p></remarks>
public static IEnumerable <ProductInstallation> GetProducts(
string productCode, string userSid, UserContexts context)
{
StringBuilder buf = new StringBuilder(40);
UserContexts targetContext;
StringBuilder targetSidBuf = new StringBuilder(40);
for (uint i = 0; ; i++)
{
uint targetSidBufSize = (uint)targetSidBuf.Capacity;
uint ret = NativeMethods.MsiEnumProductsEx(
productCode,
userSid,
context,
i,
buf,
out targetContext,
targetSidBuf,
ref targetSidBufSize);
if (ret == (uint)NativeMethods.Error.MORE_DATA)
{
targetSidBuf.Capacity = (int)++targetSidBufSize;
ret = NativeMethods.MsiEnumProductsEx(
productCode,
userSid,
context,
i,
buf,
out targetContext,
targetSidBuf,
ref targetSidBufSize);
}
if (ret == (uint)NativeMethods.Error.NO_MORE_ITEMS)
{
break;
}
if (ret != 0)
{
throw InstallerException.ExceptionFromReturnCode(ret);
}
yield return(new ProductInstallation(
buf.ToString(),
targetSidBuf.ToString(),
targetContext));
}
}
