Source code ：

<span style="font-size:24px;">using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Linq;

using System.Windows.Forms;

using DevExpress.XtraEditors;

using System.Data.SqlClient;

using DevExpress.XtraTreeList.Nodes;

namespace lianxi

{

public partial class treelist_shijian : DevExpress.XtraEditors.XtraForm

{

public treelist_shijian()

{

InitializeComponent();

ShuJu();

}

// Bind the read database to treeList1 in

public void ShuJu()

{

SqlConnection conn = new SqlConnection("server=(local);database=DEV_Test;Integrated Security=true;");

SqlCommand comm = new SqlCommand("select from Table_treelist", conn);//select Write later “” Otherwise, the effect of tree structure will not come out

conn.Open();

SqlDataReader reader = comm.ExecuteReader();

DataTable dt = new DataTable();

dt.Load(reader);

this.treeList1.DataSource = dt;

this.treeList1.KeyFieldName = " Number ";

treeList1.ParentFieldName = " Parent class number ";

treeList1.Columns[0].Caption = " company ";

conn.Close();

// Show check boxes

treeList1.OptionsView.ShowCheckBoxes = true;

}

// When selecting a node , Select all the child nodes of this node When canceling a node , All child nodes of this node are deselected

private void SetCheckedChildNodes(TreeListNode node, CheckState check)

{

for (int i = 0; i < node.Nodes.Count; i++)

{

node.Nodes[i].CheckState = check;

SetCheckedChildNodes(node.Nodes[i], check);

}

}

// When all the child nodes of a node are selected , Select... For this node When not all the child nodes of a node are selected , This node does not select

private void SetCheckedParentNodes(TreeListNode node, CheckState check)

{

if (node.ParentNode != null)

{

CheckState parentCheckState = node.ParentNode.CheckState;

CheckState nodeCheckState;

for (int i = 0; i < node.ParentNode.Nodes.Count; i++)

{

nodeCheckState = (CheckState)node.ParentNode.Nodes[i].CheckState;

if (!check.Equals(nodeCheckState))// As long as any one is different from its selected status, that is, the parent node status is not all selected

{

parentCheckState = CheckState.Unchecked;

break;

}

parentCheckState = check;// otherwise （ The sibling nodes of this node are all selected in the same status ）, The selected status of the parent node is the selected status of the node

}

node.ParentNode.CheckState = parentCheckState;

SetCheckedParentNodes(node.ParentNode, check);// Traverse the parent node

}

}

// Trigger the select node event

private void treeList1_AfterCheckNode(object sender, DevExpress.XtraTreeList.NodeEventArgs e)

{

SetCheckedChildNodes(e.Node, e.Node.CheckState);

SetCheckedParentNodes(e.Node, e.Node.CheckState);

Kafka Practical notes

About this note , In order not to affect everyone's reading experience , I can only show some chapters and core screenshots in the article

• Kafka introduction
• Why choose Kafka
• Karka Installation 、 Management and configuration

• Kafka The cluster of
• first Kafka Program
• 

afka The producers of

• Kafka The consumer
• In depth understanding of Kafka
• Reliable data transmission

• Spring and Kalka Integration of
• Sprinboot and Kafka Integration of
• Kafka The practice of cutting peaks and filling valleys
• Data pipeline and streaming ( Understanding can )

• Kafka The practice of cutting peaks and filling valleys

This article has been  CODING Open source project ：【 A big factory Java Analysis of interview questions + Core summary learning notes + The latest explanation video + Actual project source code 】 Included