请教entity framework中数据更新的问题

db.Devies 是个DBSet 啊, 应该是
db.Entry(d).State = EntityState.Modified;
db.SaveChanges();

代码：如下
var viewModel = new netsecreContext();
viewModel.Devies=db.Devies;

foreach (Devie d in viewModel.Devies)
{
SimpleSnmp snmp = new SimpleSnmp(d.MsgHostname, d.device_comm);

Dictionary result = snmp.Get(SnmpVersion.Ver1,
new string[] { ".1.3.6.1.2.1.1.1.0" });
foreach (KeyValuePair kvp in result)
{
d.device_ios = kvp.Value.ToString();
}
if (ModelState.IsValid)
{
db.Entry(db.Devies).State = EntityState.Modified;
db.SaveChanges();
}
}
return RedirectToAction("Index");

转载，仅供参考。