如何使用Foreach循环将数据从数据表节点迭代到treenode中

Question

我正在尝试使用foreach循环创建树视图节点。我有2个数据表，当前正在通过foreach循环运行以获取行。我的第一个foreach循环成功地将第一个数据表行放入树视图节点。问题是将第二个数据表行放入每个父节点。

第一个数据表的结构是：

job       |suffix
J000027399   0
J000027399   1
J000027399   2
J000027399   3
J000027399   4
J000027399   5

第二个表结构是：

job       |suffix|operNum
J000027399  0        10
J000027399  0        20
J000027399  0        30
J000027399  1        10
J000027399  1        20
J000027399  2        10
J000027399  3        10
J000027399  4        10
J000027399  4        20
J000027399  5        10

我需要像这样填充树节点：

0 
 10
 20
 30
1
 10
 20
2
 10
3
 10
4
 10
 20
5
 10

父节点基于第一数据表，子节点基于第二数据表。

到目前为止是我的代码

using (SqlDataAdapter jobAdapter = new SqlDataAdapter(cmd))
{            
    DataTable dtJ = new DataTable();
    jobAdapter.Fill(dtJ);

    foreach (DataRow jRow in dtJ.Rows)
    {
        tvBomView.Nodes.Add("job", jRow["Suffix"].ToString());
    }

    SqlCommand cmdStageTwo = new SqlCommand("dbo.CHS_Bom_View_Grab_JobRoute", conn);
    cmdStageTwo.CommandType = CommandType.StoredProcedure;
    cmdStageTwo.Parameters.Add("@Job", SqlDbType.NVarChar, 10).Value = txtJob.Text;

    using (SqlDataAdapter jobRouteAdapter = new SqlDataAdapter(cmdStageTwo))
    {
        DataTable dtJR = new DataTable();
        jobRouteAdapter.Fill(dtJR);

        foreach (TreeNode node in tvBomView.Nodes)
        {
            foreach (DataRow jrRow in dtJR.Rows)
            {
                if (node.Text != jrRow["Suffix"].ToString())
                {
                    break;
                }
                else if (node.Text == jrRow["Suffix"].ToString())
                {
                    tvBomView.Nodes["job"].Nodes.Add("oper", "Oper: " + 
                        jrRow["OperNum"].ToString());
                }
            }
        }
    }
}

Answer 1

尝试以下内容：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            DataTable dt = new DataTable();
            dt.Columns.Add("job", typeof(string));
            dt.Columns.Add("suffix", typeof(int));
            dt.Columns.Add("operNum", typeof(int));

            dt.Rows.Add(new object[] { "J000027399", 0, 10});
            dt.Rows.Add(new object[] { "J000027399", 0, 20});
            dt.Rows.Add(new object[] { "J000027399", 0, 30});
            dt.Rows.Add(new object[] { "J000027399", 1, 10});
            dt.Rows.Add(new object[] { "J000027399", 1, 20});
            dt.Rows.Add(new object[] { "J000027399", 2, 10});
            dt.Rows.Add(new object[] { "J000027399", 3, 10});
            dt.Rows.Add(new object[] { "J000027399", 4, 10});
            dt.Rows.Add(new object[] { "J000027399", 4, 20});
            dt.Rows.Add(new object[] { "J000027399", 5, 10});

            var groups = dt.AsEnumerable()
                .OrderBy(x => x.Field<int>("suffix"))
                .ThenBy(x => x.Field<int>("operNum"))
                .GroupBy(x => x.Field<int>("suffix"));

            foreach (var group in groups)
            {
                TreeNode node = new TreeNode(group.Key.ToString());

                treeView1.Nodes.Add(node);
                foreach (DataRow row in group)
                {
                    node.Nodes.Add(row.Field<int>("operNum").ToString());
                }

            }
            treeView1.ExpandAll();
        }
    }
}

Answer 2

您可以同时加载DataTable-s并将它们与TreeView一起传递给创建树的方法：

{
//The method where you call dtJ and dtJR from the database:
ToTreeView(tvBomView, dtj, dtJR);
}

ToTreeView(..)方法：

private void ToTreeView(TreeView tv, DataTable dt1, DataTable dt2)
{
    tv.SuspendLayout();
    tv.Nodes.Clear();

    //Create a temp IEnumerable of anonymous type:
    var items = dt1.Rows.Cast<DataRow>()
        .Select(x => new
        {
            Parent = x,
            Children = dt2.Rows.Cast<DataRow>()
            .Where(y => y["suffix"].ToString() == x["suffix"].ToString())
        });

    foreach(var item in items)
    {
        var parentNode = tv.Nodes.Add("job", item.Parent["suffix"].ToString());

        foreach(var child in item.Children)
        {
            parentNode.Nodes.Add("oper", $"Oper: {child["operNum"].ToString()}");
        }
    }

    tv.EndUpdate();
}

或者只是：

private void ToTreeView(TreeView tv, DataTable dt1, DataTable dt2)
{
    tv.SuspendLayout();
    tv.Nodes.Clear();

    dt1.Rows.Cast<DataRow>()
        .ToList()
        .ForEach(x =>
        {
            var p = tv.Nodes.Add("job", x["Suffix"].ToString());
            dt2.Rows.Cast<DataRow>()
            .Where(y => x["Suffix"].ToString() == y["Suffix"].ToString())
            .ToList()
            .ForEach(y => p.Nodes.Add("oper", $"Oper: {y["operNum"].ToString()}"));
        });

    tv.EndUpdate();
}