public IEnumerable <KeyValuePair <uint, List <IPEndPoint> > > GetAcceptableClients() { try { if (this.chkAcceptableClients.Checked) { var result = new List <KeyValuePair <uint, List <IPEndPoint> > >(); var splitedText = this.txtAcceptableClients.Text.Trim(). Split(new string[] { ";", ";", "\r\n" }, StringSplitOptions.RemoveEmptyEntries); foreach (var item in splitedText) { var value = HelperTools.ParseIdAndEndPoints(item); result.Add(value); } return(result); } else { return(null); // 空引用表示不指定客户端,即接受所有客户端。 } } catch (System.Exception ex) { MessageBox.Show("无法解析指定的客户端," + ex.Message + "\r\n多个客户端使用半角逗号分隔。", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); return(null); } }