我们如何获得具有多个子节点的树视图结构答案

【问题标题】：how can we get a treeview structure with nultiple childnodes我们如何获得具有多个子节点的树视图结构
【发布时间】：2016-07-24 13:27:22
【问题描述】：

在我的应用程序中，我需要带有子节点的树视图结构，应用程序应该采用这样的方式，即我可以拥有多个没有节点的子节点。当用户点击这些节点时，它应该可以展开我该怎么做

【问题讨论】：

你有一个 SQL 注入漏洞。
您看到Columns 属性了吗？

标签： c# asp.net datatable treeview

【解决方案1】：

如果我理解您的意思，您可以添加一个额外的节点作为标题，例如：

private void PopulateTreeView(DataTable dtParent, int parentId, TreeNode treeNode)
    {


        foreach (DataRow row in dtParent.Rows)
        {
            string Value = string.Empty;
            string header = string.Empty;
            // this is just extra node for header
            if (dtParent.Columns.Count > 2)
            {
                header += "Name" + " " + " ";
                header += "VehicleType" + " " + " ";
                header += "Capacity" + " " + " ";
            }
            else
            {
                header += "Name" + " " + " ";
            }
            TreeNode headerNode = new TreeNode
            {
                Text = header.ToString(),
                 // Any value that you want and has no confelict with other
                Value = row["Id"].ToString()

            };


            if (dtParent.Columns.Count > 2)
            {
                Value += row["Name"].ToString() + " " + " ";
                Value += row["VehicleType"].ToString() + " " + " ";
                Value += row["Capacity"].ToString() + " " + " ";
            }
            else
            {
                Value += row["Name"].ToString() + " " + " ";
            }

            TreeNode child = new TreeNode
            {
                Text = Value.ToString(),
                Value = row["Id"].ToString()

            };



            if (parentId == 0)
            {
                TreeView1.Nodes.Add(child);
                DataTable dtChild = this.GetData("SELECT Id, Name,VehicleType,Capacity FROM Bikes WHERE VehicleTypeId = " + child.Value);
                PopulateTreeView(dtChild, int.Parse(child.Value), child);
            }
            else
            {
                treeNode.ChildNodes.Add(child);
            }
        }
    }

或者如果你的意思是找到每个列名，你可以使用这个：

private void PopulateTreeView(DataTable dtParent, int parentId, TreeNode treeNode)
    {


        foreach (DataRow row in dtParent.Rows)
        {
            string Value = string.Empty;
            string header = string.Empty;
            // Get all columns name
            for (var i=0;i<(dtParent.Columns.Count)-1;i++)
            {
                header += dtParent.Columns[i].ColumnName + "  ";
            }

            TreeNode headerNode = new TreeNode
            {
                Text = header.ToString(),
                 // Any value that you want and has no confelict with other
                Value = row["Id"].ToString()

            };


            if (dtParent.Columns.Count > 2)
            {
                Value += row["Name"].ToString() + " " + " ";
                Value += row["VehicleType"].ToString() + " " + " ";
                Value += row["Capacity"].ToString() + " " + " ";
            }
            else
            {
                Value += row["Name"].ToString() + " " + " ";
            }

            TreeNode child = new TreeNode
            {
                Text = Value.ToString(),
                Value = row["Id"].ToString()

            };



            if (parentId == 0)
            {
                TreeView1.Nodes.Add(child);
                DataTable dtChild = this.GetData("SELECT Id, Name,VehicleType,Capacity FROM Bikes WHERE VehicleTypeId = " + child.Value);
                PopulateTreeView(dtChild, int.Parse(child.Value), child);
            }
            else
            {
                treeNode.ChildNodes.Add(child);
            }
        }
    }

【讨论】：