Question

我有以下表结构，它可能不是一个正确的结构，但不幸的是，这就是我所得到的。

id |  Name  | Parent  | Status
 1    First     0       Active
 2    Child     1       Active
 3    2Child    2       Inactive

逻辑：

按父级加载Root = 0和状态
OnPopulate按父级ID加载子级，并在root
之后为每个级别加载状态
我的问题是，如果状态为“非活动”，并且我想查看哪些选项处于非活动状态，我不能，因为前两个选项处于活动状态。我需要的是能够在我的树视图中查看所有级别，直到非活动或活动的选项。

我尝试过以下sql语句

select distinct
        m.Id,
        m.Name,
        m.Parent,
        m.[Status]
from mytable m
where m.Parent = 3 and m.[Status] = 'I'
union
select 
        Id,
        Name,
        Parent,
        [Status]
from mytable
where ID in(select distinct
        o.ID
from mytable o
where o.ID = 3 and o.[Status] = 'I') and Parent = 3

我已经用完sql和编码的想法来解决这个问题......希望有人可以指导我朝着正确的方向发展..谢谢

还在代码中尝试了这个：

    protected void mytree_TreeNodePopulate(object sender, TreeNodeEventArgs e)
    {
        //this is just a class that loads the values from db
        MYList templist = new ListSyFamily();
        templist.LoadAll();//(ddlStatus.SelectedValue, Convert.ToInt32(e.Node.Value));

        foreach (temp temp in templist)
        {
            if (temp.Status == ddlStatus.SelectedValue && temp.Parent == Convert.ToInt32(e.Node.Value))
            {
                TreeNode child = new TreeNode();
                child.Text = temp.Description;
                child.Value = temp.Id.ToString();
                if (child.ChildNodes.Count == 0)
                    child.PopulateOnDemand = true;

                child.ToolTip = "Ver sub-opciones";
                //child.SelectAction = TreeNodeSelectAction.SelectExpand;

                child.CollapseAll();

                e.Node.ChildNodes.Add(child);
            }
        }
    }

Answer 1

以下是我们处理此问题的方法。

假设您有一个名为MyRecord的类来保存数据库中的每一行数据：

public class MyRecord
{
    public int Id {get; set; }
    public int ParentId {get; set; }

    public string Name { get; set; }
    public string Status { get; set; }

    // The children of this node
    public MyRecordCollection Children = new MyRecordCollection();
}

然后你有一个集合类型来保存这些由他们的id索引的记录：

public class MyRecordCollection : System.Collections.Generic.Dictionary<int, MyRecord>
{

}

这是代码（从DB中检索未显示）来预处理记录，然后将它们添加到树中：

        MyRecordCollection cAllRecords;
        MyRecordCollection cParentRecords = new MyRecordCollection();

        // This is a method that just loads the records
        cAllRecords = LoadAllRecords();

        // Cycle through each of the records
        foreach (MyRecord oRecord in cAllRecords.Values)
        {
            if (oRecord.Id == 0)
            {
                // If the record is a parent record, add it to the list of parents
                cParentRecords.Add(oRecord.Id, oRecord);
            }
            else
            {
                // Otherwise, add the current record to its parent's list of children
                cAllRecords[oRecord.ParentId].Children.Add(oRecord.Id, oRecord);
            }
        }

        AddNodesToTree(cParentRecords, this.treeView1.Nodes);

最后，将记录添加到树中的递归方法：

    /// <summary>
    /// A recursive method to add all of the records to the specified collection of nodes
    /// </summary>
    /// <param name="cRecords"></param>
    /// <param name="cNodes"></param>
    private void AddNodesToTree(MyRecordCollection cRecords, TreeNodeCollection cNodes)
    {
        foreach (MyRecord oRecord in cRecords.Values)
        {
            TreeNode oNode = new TreeNode();
            oNode.Text = oRecord.Name;
            oNode.Tag = oRecord;
            cNodes.Add(oNode);
            // Now add the node's children if any
            if (oRecord.Children.Count != 0)
            {
                AddNodesToTree(oRecord.Children, oNode.Nodes);
            }
        }

    }

Answer 2

好吧，如果我是你，我只需将整个表加载到内存中，然后将一个简单的DTO类集合加载到C＃中进行树视图。这似乎比在SQL中尝试很多选项容易得多。

Treeview与父/子问题按状态加载

2 个答案: