C form application treeview control use

Preface ：

TreeView Controls are also used frequently in form applications , We are using TreeView It is generally a hierarchical display of resources , Similar to the concave representation of the tree in the data structure . Many companies use TreeView Control as a hierarchical view of file display information , Like Windows The directory of the explorer in .TreeView Each item of information in the control has a related Node object .TreeView Show Node Object's hierarchical directory structure , Every Node Objects are composed of one Label Object and its associated bitmap . In establishment TreeView After control , You can expand and collapse 、 Show or hide the nodes .TreeView Control is generally used to display file and directory structure 、 Class hierarchy in the document 、 Hierarchy in index and other information with hierarchical directory structure .

Once a day , Prevent puppy love

1.TreeView Control use

1.1 TreeView Control common properties

Index  Get the position of the tree node in the tree node collection
Nodes  Gets the collection of tree nodes assigned to the tree view control
Parent  Gets or sets the parent container of the control
SelectedNode  Gets or sets the tree node currently selected in the tree view control
ExpandAll  Expand all tree nodes
Checked  Gets or sets a value , Used to indicate whether the tree node is selected
Text  Gets or sets the text displayed in the tree node label
Expand  Expand tree node
Clear  Empty the tree
Remove  Removes the current tree node from the tree view control .


1.2  Create a form file and change the name

2. Design interface

We use simple cases to achieve the effect

3. Add and delete data

3.1  Click on treeView Edit node

3.2  stay TreeView Add data to the editor

notes ： We add data statically here , The deletion or addition made later is also static , It doesn't work to delete later

3.3 TreeView Control to add root node operation

notes ： The blogger's addition here is not added to the database , It's just a static display, not static writing treeView, It is stored in memory and released at the end

3.4 TreeView Control to add child nodes

We need to get the selected node and judge whether it is empty , If it is not empty, it means that there is a root node that can be added , If there is no choice, we need to add child nodes .

3.5 TreeView Control deletion

Here, we need to judge whether the parent node of the selected node is empty , If it is empty, it means that this node is the root node and needs to be deleted , If it is not empty, it means it is a child node , We find the child node from the parent node and delete .

3.6 TreeView Control to clear the tree

We use it directly here clear Just delete it . There is no other operation

4. Overall effect display

4.1 Code demonstration

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

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

 private void button1_Click(object sender, EventArgs e)
 {
 TreeNode treeNode = new TreeNode(textBox1.Text, 2, 2);
 treeView1.Nodes.Add(treeNode);
 treeView1.Select();
 }

 private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
 {

 }

 private void button2_Click(object sender, EventArgs e)
 {
 TreeNode selectdnode = treeView1.SelectedNode;
 if(selectdnode!=null)
 {
 TreeNode chnode = new TreeNode(textBox2.Text, 2, 2);
 selectdnode.Nodes.Add(chnode);
 selectdnode.Expand();
 treeView1.Select();
 }
 else
 {
 MessageBox.Show(" Please select the child node you want to add ");
 }
 }

 private void button3_Click(object sender, EventArgs e)
 {
 TreeNode selectnode = treeView1.SelectedNode;
 TreeNode parentnode = selectnode.Parent; 
 if(parentnode == null)
 {
 treeView1.Nodes.Remove(selectnode);
 }
 else
 {
 parentnode.Nodes.Remove(selectnode);
 }
 treeView1.Select();
 }

 private void button4_Click(object sender, EventArgs e)
 {
 treeView1.Nodes.Clear();
 }

 private void button5_Click(object sender, EventArgs e)
 {
 this.textBox1.Clear();
 this.textBox2.Clear();
 }
 }
}


summary ：

TreeView Control explains that the blogger does not use the database to operate , But simply use variables to operate , When using the database, we need to use the depth of nodes to establish , Each layer may have a table , Finally, at the bottom is our data , We get each layer Name Make trees , Implement the concave representation of resources , Bloggers simply introduce the use of , It is more suitable for novices , Is to write static data and operate without connecting to the database , If you need to connect to the database and follow the blogger, the next article may write , Okay , Creation is not easy to like, pay attention to comment collection , Thank you, boss ！！！！