根据状态加载父/子问题的树视图

本文关键字：问题 视图 状态 加载 | 更新日期: 2023-09-27 18:17:38

我有下面的表结构它可能不是一个正确的结构，但不幸的是，这是我给的。

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

逻辑:

  1. Load Root by Parent = 0 and Status

  2. OnPopulate根据父ID和状态为根后的每个级别加载子

    我的问题是，如果状态是"非活动"，我想看看哪些选项是非活动的，我不能，因为前两个选项是活动的。我需要的是能够在我的树视图查看所有的水平下降到选项，是不活动或活动。

我尝试了以下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

我已经用完了sql和编码的想法来弄清楚，希望有人能引导我在正确的方向，谢谢

也试过这个代码:

    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);
            }
        }
    }

根据状态加载父/子问题的树视图

我们是这样处理的

假设您有一个名为MyRecord的类来保存DB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记录的id索引:

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

下面是预处理记录的代码(未显示从DB检索)，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);
            }
        }
    }

嗯，如果我是你，我会把整个表加载到内存中，放入一个简单的DTO类的集合中，然后用c#计算出你的树视图。这似乎比在SQL中尝试大量选项要容易得多。

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