How to use Treeview control in Asp.net applications

How to use Treeview control in Asp.net applications

Read more: http://www.developerscode.com/2012/08/how-to-use-treeview-control-in-aspnet.html#ixzz2Meq1l641

Hi friends, in this article I would like to explain how to bind data to Tree View control in asp.net using c#. From last few weeks we are getting so many requests about tree view control example in asp.net applications. This time we are going to explain a basic tutorial about treeview control for beginner’s.

Please follow the steps

Step :1

 In this article I am considered States and its districts as nodes and its child nodes. Let us consider a sql table as below:

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1.    
2. SET ANSI_NULLS ON  
3. GO  
4.   
5. SET QUOTED_IDENTIFIER ON  
6. GO  
7.   
8. SET ANSI_PADDING ON  
9. GO  
10.   
11. CREATE TABLE [dbo].[ExampleOnTreeView](  
12.  [Id] [int] NULL,  
13.  [StateId] [int] NULL,  
14.  [StateName] [varchar](50) NULL  
15. ) ON [PRIMARY]  
16.   
17. GO  
18.   
19. SET ANSI_PADDING OFF  
20. GO  

 Please find the below screen shot(ExampleTreeViewTable.jpg) for sample data that I shown in tree view output.

 

Step 2:

Then,coming to code for TreeView control in asp.net: In .aspx page:

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1. <%@ Page Title="" Language="C#" AutoEventWireup="true" CodeFile="TreeViewExample.aspx.cs" Inherits="Year" %><title></title><form id="form1" runat="server">  
2. <span style="font-size: small;">Tree View Example : <asp:treeview id="TreeViewStatesAndDistricts" imageset="Msdn" runat="server">  
3.     </asp:treeview>  
4.     </span></form>  
5. <span style="font-size: small;">  
6. </span>  

Step 3:

In .aspx.cs page:

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1. <span style="font-size: small;">  
2. using System;  
3. using System.Web;  
4. using System.Web.UI;  
5. using System.Web.UI.WebControls;  
6. using System.Data.SqlClient;  
7. using System.Data;  
8. using System.Configuration;  
9.   
10. public partial class TreeViewExample : System.Web.UI.Page  
11. {  
12.     SqlConnection con;  
13.     protected void Page_Load(object sender, EventArgs e)  
14.     {  
15.         try  
16.         {  
17.             con = new SqlConnection(ConfigurationManager.ConnectionStrings["TestConnection"].ConnectionString);  
18.             if (!Page.IsPostBack)  
19.             {  
20.                 //Getting State Names from the database table(ExampleOnTreeView).  
21.                 SqlCommand cmdStates = new SqlCommand("Select Id,StateName from ExampleOnTreeView where StateId is null", con);   
22.                 DataSet dsStates = new DataSet();  
23.                 SqlDataAdapter daStates = new SqlDataAdapter(cmdStates);  
24.                 daStates.Fill(dsStates);  
25.   
26.                 int StatesCount = dsStates.Tables[0].Rows.Count;  
27.                 string[] Names = new string[StatesCount];  
28.                 int i = 0;  
29.   
30.                 foreach (DataRow drStates in dsStates.Tables[0].Rows)  
31.                 {  
32.                     TreeViewStatesAndDistricts.Nodes.Add(new TreeNode(drStates["StateName"].ToString(), drStates["Id"].ToString()));  
33.                     Names[i] = drStates["id"].ToString();  
34.                     i++;  
35.                 }  
36.   
37.   
38.                 if (i > 0)  
39.                 {  
40.                     // Getting District Names from the existing state.  
41.                     string DistrictsQuery = "";  
42.                     i = 0;  
43.                     for (int j = 0; j < StatesCount; j++)  
44.                     {  
45.                         if (j == 0)  
46.                             DistrictsQuery = "StateId = " + Names[j];  
47.                         else  
48.                             DistrictsQuery += " or StateId = " + Names[j];  
49.                     }  
50.   
51.                     SqlCommand cmdDistricts = new SqlCommand("Select Id,StateId,StateName from ExampleOnTreeView where " + DistrictsQuery, con);  
52.                     DataSet dsDistricts = new DataSet();  
53.                     SqlDataAdapter daDistricts = new SqlDataAdapter(cmdDistricts);  
54.                     daDistricts.Fill(dsDistricts);  
55.   
56.                     StatesCount = dsDistricts.Tables[0].Rows.Count;  
57.                     Names = new string[StatesCount];  
58.   
59.                     foreach (DataRow drDistricts in dsDistricts.Tables[0].Rows)  
60.                     {  
61.                         TreeViewStatesAndDistricts.FindNode(drDistricts["StateId"].ToString()).ChildNodes.Add(new TreeNode(drDistricts["StateName"].ToString(), drDistricts["Id"].ToString()));  
62.                     }  
63.   
64.                 }  
65.             }  
66.         }  
67.         catch  
68.         {   
69.           
70.         }  
71.     }     
72. }  
73.   
74. </span>  

After executing the above code by pressing (F5) it will generate the States & districts in Tree View format as below (ExampleOnTreeView.jpg): 

Read more: http://www.developerscode.com/2012/08/how-to-use-treeview-control-in-aspnet.html#ixzz2Meq6asUF