Get data from SharePoint Online List using VB.NET - vb.net

Question

I'm developing a solution to get data from SharePoint Online List, but when I try to retrieve and execute the query, do a error. The error is.
System.Net.WebException: 'The remote server returned an error: (403) Forbidden.'
Im using 4 textboxs (URL, User, Password, NameList) and a Datagridview.
Using context As ClientContext = New ClientContext(TextBox1.Text.Trim())
context.AuthenticationMode = ClientAuthenticationMode.[Default]
context.Credentials = New NetworkCredential(TextBoxName.Text.Trim(), TextBoxPassword.Text.Trim(), "https://example.sharepoint.com/sites/SPSite/")
Dim webObj As Web = context.Web
Dim listObj As List = webObj.Lists.GetByTitle(TextBoxLista.Text.Trim())
Dim cqObj As CamlQuery = CamlQuery.CreateAllItemsQuery(100)
Dim collObj As ListItemCollection = listObj.GetItems(cqObj)
context.Load(collObj)
context.ExecuteQuery() 'Line whit error
End Using
Could you help me to know the reason for the error and how to solve it?
Thank you in advance.
Regards.

Answer 1

This is the code whit the solution.
Thank you.
Imports Microsoft.SharePoint.Client
Imports Microsoft.SharePoint
Imports System.Security
Imports System.Net
Public Class Form4
Dim siteUrl As String = "https://namedomain.sharepoint.com/sites/TaskSP/"
'namedomain is the name of the site domain, TaskSP is the name site.
Dim context As New ClientContext(siteUrl)
Dim web As Web
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Try
Dim userNameSP As String = TextBox1.Text
'Textbox1.text is the mail account to access site.
Dim password As String = TextBox2.Text
'Textbox2.text is the password of your mail account to access site.
Dim secureString As SecureString = New NetworkCredential("", password).SecurePassword
Dim cred = New SharePointOnlineCredentials(userNameSP, secureString)
Dim clientContext As New ClientContext(siteUrl)
clientContext.Credentials = cred
Dim web As Web = clientContext.Web
Dim oWebsite As Web = clientContext.Web
Dim collList As ListCollection = oWebsite.Lists
Dim oList As List = collList.GetByTitle("TestList")
'TestList is the name of the list you want to query
clientContext.Load(oList)
clientContext.ExecuteQuery()
Catch ex As Exception
Console.WriteLine(ex.Message)
End Try
End Sub
End Class
I hope this is useful if you need it.
Regards.