Question

目前，我的网页上有一个树形视图和一个网格视图。 TreeView显示“电子邮件收件箱文件夹”列表。 GridView显示来自那些“收件箱”文件夹的电子邮件。但是，当我最初加载我的电子邮件网页时，我的gridView上的分页不起作用并返回错误。我的想法是，我在！IsPostBack方法期间未绑定gridView。但是我正在尝试多种方法来解决此问题。请帮助我调查此问题，并提出解决此问题的最佳方法。请参考以下代码。谢谢

protected void Page_Load(object sender, EventArgs e)
    {
        B_EmailMsgDelete.Attributes.Add("onclick", "javascript:if(!doDeleteEmailMsg()) return false;");
        IB_EmailMover.Attributes.Add("onclick", "javascript:if(!doMoveEmailMsg()) return false;");

        if (!IsPostBack)
        {
            TreeNode rootTreeNode = new TreeNode();
            rootTreeNode.Text = string.Format(CultureInfo.CurrentCulture, "&nbsp;{0}", this.curEmailBox);
            rootTreeNode.Value = this.EmailFolderList[0];
            rootTreeNode.ImageUrl = "../../Images/emailbox.gif";

            for (int i = 0; i < this.EmailFolderList.Length; i++)
            {
                if (i > 0)
                {
                    TreeNode treeNode = new TreeNode();
                    treeNode.Text = string.Format(CultureInfo.CurrentCulture, "&nbsp;{0}", this.EmailFolderList[i]);
                    treeNode.Value = this.EmailFolderList[i];
                    treeNode.ImageUrl = "../../Images/folder.gif";
                    rootTreeNode.ChildNodes.Add(treeNode);
                }

                DL_MoveTo.Items.Add(this.EmailFolderList[i]);
            }

            TV_EmaiBox.Nodes.Add(rootTreeNode);
            this.GetListEmailList(rootTreeNode.Value);
        }
    }

protected void TV_EmaiBox_SelectedNodeChanged(object sender, EventArgs e)
    {
        string checkFolder = TV_EmaiBox.SelectedNode.Value.ToString();
        this.GetListEmailList(checkFolder);
    }

protected void GV_EmailList_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        GV_EmailList.PageIndex = e.NewPageIndex;
        string checkFolder = TV_EmaiBox.SelectedNode.Value.ToString();
        this.GetListEmailList(checkFolder);
    }

private void GetListEmailList(string folderName)
    {
        try
        {
            LB_ActionError.Text = string.Empty;
            PH_MsgDetail.Visible = true;

            var emails = EmailMsg.GetEmailListInFolder(folderName);
            LB_CurBox.Text = string.Format(CultureInfo.CurrentCulture, "{0} ({1})", folderName, emails.Count);

            int intTotal = emails.Count;
            if (intTotal == 0)
            {
                LB_ActionStatus.Text = Utility.SetActStatus(true, "There is no email message found in this folder.");
                GV_EmailList.DataSource = new ArrayList();
                GV_EmailList.DataBind();
                GV_EmailList.Visible = false;
            }
            else
            {
                LB_ActionStatus.Text = Utility.SetActStatus(true, string.Format(CultureInfo.CurrentCulture, "There are {0} email message(s) found in this folder.", intTotal));
                GV_EmailList.DataSource = emails;
                GV_EmailList.DataBind();
                GV_EmailList.Visible = true;

                GV_EmailList.SelectedIndex = -1;
            }
        }
        catch (Exception ex)
        {
            LB_ActionStatus.Text = Utility.SetActStatus(false, ex.Message.ToString());
        }

        LB_AdminEmailBox.Text = string.Format(CultureInfo.CurrentCulture, Entity.GetSetting("MailBoxAddress"), folderName);
    }

当我单击gridview中的页面索引时，错误来自此行。

string checkFolder = TV_EmaiBox.SelectedNode.Value.ToString();

我知道我正在尝试在GridView方法中调用TreeView对象。有什么办法可以解决此问题？谢谢

TreeView.SelectedNode.get返回Null

0 个答案: