ASP.NET Web 开发之TreeView无限级分类

if (!Page.IsPostBack)
{
BindTrv();
}
//添加顶级分类
protected void btnAddPca_Click(object sender, EventArgs e)
{
    string caname = txtAddPca.Text.Trim();
    string remark = txtPremark.Text.Trim();
    if (caname.Length == 0 || remark.Length == 0)
    {
        Utility.Tool.Alert("请输入完整再提交", this.Page);
        return;
    }
    string pid = "0";
    if (int.Parse(pid) + 1 > 99)
    {
        Utility.Tool.Alert("只能输入99种分类", this.Page);
        return;
    }
    string bh = cdal.GetBH(pid);
    cdal.Add(new Model.Category()
    {
        caname = caname,
        bh = bh,
        pid = int.Parse(pid),
        remark = remark,
    });
    BindTrv();
    Utility.Tool.AlertAndGo("添加成功", Request.Url.ToString(), this.Page);
    ClearTxt();
}
//添加子分类
protected void btnAddca_Click(object sender, EventArgs e)
{
    string id = trvca.SelectedValue;
    int x;
    if (int.TryParse(id, out x))
    {
        string caname = txtAddca.Text.Trim();
        string remark = txtremark.Text.Trim();
        if (caname.Length == 0 || remark.Length == 0)
        {
            Utility.Tool.Alert("请输入完整再提交", this.Page);
            return;
        }
        string pid = hfid.Value;
        string bh = cdal.GetBH(pid);
        if (cdal.CalcCount("pid=" + pid) == 99)
        {
            Utility.Tool.Alert("只能输入99种分类", this.Page);
            return;
        }
        cdal.Add(new Model.Category()
        {
            remark = remark,
            pid = int.Parse(pid),
            caname = caname,
            bh = bh,
        });
        BindTrv();
        Utility.Tool.AlertAndGo("添加成功", Request.Url.ToString(), this.Page);
        ClearTxt();
    }
    else
    {
        Utility.Tool.Alert("请选择父级分类", this.Page);
        return;
    }
}
//修改分类
protected void btnMod_Click(object sender, EventArgs e)
{
    string id = hfid.Value;
    int x;
    if (int.TryParse(id, out x))
    {
        string caname = txtModca.Text.Trim();
        if (caname.Length == 0)
        {
            Utility.Tool.Alert("请输入分类名称", this.Page);
            return;
        }
        Model.Category model = cdal.GetModel(x);
        if (model != null)
        {
            model.caname = caname;
        }
        cdal.Update(model);
        BindTrv();
        Utility.Tool.AlertAndGo("修改成功", Request.Url.ToString(), this.Page);
        ClearTxt();
    }
    else
    {
        Utility.Tool.Alert("请重新选择分类", this.Page);
        return;
    }
}
//删除分类
protected void btnDel_Click(object sender, EventArgs e)
{
    string id = hfid.Value;
    int x;
    if (int.TryParse(id, out x))
    {
        Model.Category model = cdal.GetModel(x);
        if (model == null)
        {
            Utility.Tool.Alert("请重新择分类", this.Page);
            return;
        }
        if (cdal.CalcCount("pid='" + model.id + "'") > 0)
        {
            Utility.Tool.Alert("该节点下有子节点不予删除", this.Page);
            return;
        }
        if (new DAL.ProductDAL().CalcCount("cacode=" + model.code + "") > 0)
        {
         Utility.Tool.Alert("该分类下有产品不予删除", this.Page);
         return;
        }
        cdal.Delete(x);
        BindTrv();
        Utility.Tool.AlertAndGo("删除成功", Request.Url.ToString(), this.Page);
        ClearTxt();
    }
    else
    {

        Utility.Tool.Alert("请重新选择分类", this.Page);
        return;
    }

}
//清空文本
private void ClearTxt()
{
    txtAddca.Text = "";
    txtAddPca.Text = "";
    txtModca.Text = "";
    litDelca.Text = "";
    litPca.Text = "";
    hfid.Value = "";
}
//选择树
protected void trvca_SelectedNodeChanged(object sender, EventArgs e)
{
    string id = trvca.SelectedValue;
    int x;
    if (int.TryParse(id, out x))
    {
        Model.Category model = cdal.GetModel(x);
        litDelca.Text = model.caname;
        litPca.Text = model.caname;
        txtModca.Text = model.caname;
        txtMremark.Text = model.remark;
        hfid.Value = model.id.ToString();

        if (model.bh.Length==4)
        {
            txtAddca.Enabled = false;
            btnAddca.Enabled = false;
        }
        else
        {
            txtAddca.Enabled = true;
            btnAddca.Enabled = true;
        }

    }
}
//绑定树
private void BindTrv()
{
    trvca.Nodes.Clear();
    List<Model.Category> list = cdal.GetListArray("");
    var query = list.Where(n => n.pid == 0);
    foreach (var item in query)
    {
        TreeNode node = new TreeNode(item.caname, item.id.ToString());
        AddChildNode(node, list);
        trvca.Nodes.Add(node);
    }
    trvca.CollapseAll(); //关闭节点 ExpandAll(); //打开节点
}
//递归绑定树
private void AddChildNode(TreeNode node, List<Model.Category> list)
{
    var query = list.Where(n => n.pid.ToString() == node.Value);
    foreach (var item in query)
    {
        TreeNode n = new TreeNode(item.caname, item.id.ToString());
        node.ChildNodes.Add(n);
        AddChildNode(n, list);
    }
}



//通过pid生成bh
public string GetBH(string pid)
{
    string sql = "select max(bh) from bbs_category where pid=@pid";
    Database db = DatabaseFactory.CreateDatabase();
    DbCommand dbCommand = db.GetSqlStringCommand(sql);
    db.AddInParameter(dbCommand, "pid", DbType.Int32, pid);
    object bh = db.ExecuteScalar(dbCommand);
    if (bh == null || bh.ToString() == "")
    {
        if (pid == "0")
        {
            return "01";
        }
        else
        {
            return GetModel(int.Parse(pid)).bh + "01";
        }
    }
    else
    {
        string tmp = bh.ToString();
        string front = tmp.Substring(0, tmp.Length - 2);
        string last = tmp.Substring(tmp.Length - 2);
        return front + (int.Parse(last) + 1).ToString("D2");
    }
}