Короче я вот так сделал
var tmplist = project.Lists["gram"];
var name = project.Variables["search"].Value;
var num = tmplist.Count;
var n = Convert.ToInt32(num);
Parallel.For(0, n, (i, loopState) =>
{
ZennoPoster.HttpGet(
tmplist,
String.Empty,
"UTF-8",
ZennoLab.InterfacesLibrary.Enums.Http.ResponceType.File,
30000,
String.Empty,
project.Profile.UserAgent,
true,
5,
AdditionalHeaders: new[] {
"Accept: image/png,image/*;q=0.8,*/*;q=0.5",
"Referer: "
},
DownloadPath: project.Directory+"\\"+name
);
if (i == n)
{
loopState.Break();
}
});