跨线程问题？ C#

Question

可能的重复：
跨线程问题？

当我调用这个线程时遇到问题。 我的想法是当您选择文件夹邮件时 - do Func1 is MessageCollections() 当 Func1 完成后，将邮件下载到文件夹中 - Func2 是 SaveMail() 下载完成一封邮件后将项目添加到列表视图 - Func3 是 AddMesToMailList() 但我的代码有问题你能帮助我吗？ 错误是：MailTree.SelectedNode.Text 行中的跨线程

private delegate void SaveMailDelegate();
            private void AddMesToMailList(IAsyncResult ia)
            {
                    ListViewItem item = new ListViewItem();
                    Mime m = EncodingMail(MailTree.SelectedNode.Text, mes);
                    item.Text = mes.MessageUid.ToString();
                    item.SubItems.Add(m.MainEntity.Subject);
                    ReturnMime(m);
                    if (mailfromname != null)
                        item.SubItems.Add(mailfromname);
                    else item.SubItems.Add(mailfrom);
                    item.SubItems.Add(m.MainEntity.Date.ToString());
                    item.SubItems.Add(mailfrom);
                    MailList.Items.Add(item);           
            }
            private delegate ImapX.MessageCollection SelectMailFolder(string foldername);
            ImapX.MessageCollection MessageCollections(string foldername)
            {
                return messages=client.Folders[foldername].Search("ALL", false);
            } 
    public void SaveMail()
            {
                string path1= "D:\\" ;
                string path2=Username;
                string path3=MailTree.SelectedNode.Text;
                string path4 = mes.MessageUid.ToString() + ".eml";
               // @"D:\" + Username + "\\" + MailTree.SelectedNode.Text + "\\" + mes.MessageUid.ToString() + ".eml")\
                string path=Path.Combine(path1,path2,path3,path4);
                string savepath = Path.Combine(path1, path2, path3);
                if (!File.Exists(path))
                {
                    mes.Process();
                    mes.SaveAsEmlToFile(savepath, mes.MessageUid.ToString());   //Store messages to a Location 
                }
            }   


    private void MailTree_AfterSelect(object sender, System.Windows.Forms.TreeViewEventArgs e)
                { 
                              MailList.Items.Clear();
                              for (int i = 0; i < client.Folders.Count; i++)
                              {                          
                                  (ContextMenuListView.Items[1] as ToolStripMenuItem).DropDownItems[i].Click += new EventHandler(MainForm_Click);
                              }
                              if (MailTree.SelectedNode.Text == Username)
                              {
                                  webBrowser1.Visible = false;//webBrowser1.DocumentText = "Hello Baby";
                                  AttachmentList.Visible = false;
                                  groupBox1.Visible = false;
                              }
                              else
                              {
                                  webBrowser1.Visible = true;
                                  groupBox1.Visible = true;
                                  string select = MailTree.SelectedNode.Text;                          
                                  //messages = client.Folders[select].Search("ALL", false);// Search mail in your choossen Folder 
                                  SelectMailFolder se = null;
                                  se += new SelectMailFolder(MessageCollections);
                                  se.BeginInvoke(select,new AsyncCallback(NewMethod), null);                          

                              }
                }

                private void NewMethod(IAsyncResult ias)
                {
                    AmoutOfMail = messages.Count(); //Amout of Mail in this Folder                                         
                    for (int i = 0; i < AmoutOfMail; i++)
                    {
                        mes = messages[i];
                        SaveMailDelegate del = null;
                        del += new SaveMailDelegate(SaveMail);
                        IAsyncResult ia = del.BeginInvoke(new AsyncCallback(AddMesToMailList), null);
                    }
                }

Answer 1

您正在单独的线程中调用AddMesToMailList。您无法与另一个线程中的 Gui 元素交互。使用Invoke切换到Gui线程

this.Invoke(new Action(AddMesToMailList))

Answer 2

根据我的疯狂猜测，您可能会遇到跨线程控制访问问题，当您从主 UI 线程以外的另一个线程触摸任何 UI 控件时，就会发生这种情况。