private void OpenRead(out TableInfo table, out BinaryReader br, IShellContext context)
{
string file = GetName(context);
file = context.ResolveFile(file, ResolveFileMode.Input);
var fr = new FileInfo(file).OpenRead();
br = new BinaryReader(fr);
string s = br.ReadString();
table = JsonTool.Deserilize <TableInfo>(s, x => x.TypeNameHandling = Newtonsoft.Json.TypeNameHandling.Auto);
table.AfterLoadLink();
}