方法一：
AppDomain appDomain = AppDomain.CreateDomain("");
appDomain.ExecuteAssembly(@"yourApp.exe");
AppDomain.Unload(appDomain);
方法二：
<system.net>
<connectionManagement>
<add address="*" maxconnection="100"/>
</connectionManagement>
</system.net>
方法三：
ServicePointManager.DefaultConnectionLimit = 100;
方法四：
protected override WebRequest GetWebRequest(Uri uri) {
HttpWebRequest req = (HttpWebRequest)base.GetWebRequest(uri);
ServicePoint currentServicePoint = req.ServicePoint;
currentServicePoint .ConnectionLimit = 100;
return req; }