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The first of all thank you for answering me, now I want to convert the code example 2 (2a and 2b included) to C# 2005 I will write again how ?
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I am working on C# Project [Windows Form Application], to update treeview nodes from excelsheet [xls] Cell [row i, Column 3] Values, while on selecting treenode, it should update corresponding Column 4 Value [row i, Column 4]. For me, Treenode are populated successfully, but on selecting the treenode, it always display first Element of treenode [Not selected one].
Populated Treenode from Excel as: [ Update Child Nodes from Column 3 elements [Column 2 Contain Parent node name and Column 3 have Child Node name], if Column 2 Value is same as Parent node name [My Module], update the child nodeunder same Parent node.]
for (int i = 0; i < worksheet.UsedRange.Rows.Count; i++)
{
string mynode = ((Excel.Range)worksheet.Cells[i + 1, 3]).Value2.ToString();
string mynode2 = ((Excel.Range)worksheet.Cells[i + 1, 2]).Value2.ToString();
if (mynode2 == mymodule)
{
TreeNode ChildNode = ParentNode.Nodes.Add(mynode);
ChildNode.Text = mynode;
}
}
On selecting the Child Node, it always give 1st Parent node. Instead of Selected Node.
for (int i = 0; i < worksheet.UsedRange.Rows.Count - 2; i++)
{
string mynodetext = ((Excel.Range)worksheet.Cells[i + 2, 3]).Value2.ToString();
string mynodetext1 = ((Excel.Range)worksheet.Cells[i + 2, 4]).Value2.ToString();
if (treeView1.SelectedNode.FirstNode.Text == mynodetext)
{
this.richTextBox1.SelectedText += Environment.NewLine + mynodetext1 + Environment.NewLine;
}
}
Please Guide, How to get correct selected Node.
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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace webbrowser2
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
webBrowser1.Navigate(http://SomeWebiste.com);
}
private void button1_Click(object sender, EventArgs e)
{
HtmlElementCollection links = webBrowser1.Document.GetElementsByTagName("a");
foreach (HtmlElement link in links)
{
try
{
if (link.InnerText.ToString() == "How to change ip in webBroswer control?")
{
link.InvokeMember("Click");
break;
}
}
catch { }
}
}
}
}
How to spoof ip when I click specific link on "some website" with proxy ip list on my computer ?
I have implemented the code with webBroswer control like above but I don't know how to spoof the ip with proxy ip lists.
Any helps would be apppreciated
Thank you
modified 22-Apr-15 12:45pm.
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I am not sure I understand the question, but I assume you just use the IP address instead of the URL, like:
webBrowser1.Navigate("http://173.194.67.106");
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Sorry my English is too bad so you didn't understand what I wanted to say.
I wanna spoof my ip whenever I click the link on "Some webiste" with proxy ip lists.
Can you help me?
Thank you
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hapiten wrote: Can you help me?
Sorry, no. I have no idea how to do that, and I am not sure it is legal.
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hapiten wrote: How to spoof ip when I click specific link on "some website" with proxy ip list
on my computer ? I have implemented the code with webBroswer control like
above but I don't know how to spoof the ip with proxy ip lists.
Do you want to redirect the user to some other IP if he clicks a link in your webbrowser?
If yes, research how to build your own proxy-server using C#.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
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I want to update a column from table but I receive: database is locked twice. The error accours only when I call updateIndex() function. Why? This is the complete code:
Load function:
private void MediuInvatare_Load(object sender, EventArgs e)
{
using (Conexiune.getConnection())
{
string select = "SELECT * FROM questions WHERE id = indexrow LIMIT 1";
using (SQLiteCommand cmd = new SQLiteCommand(select, Conexiune.getConnection()))
{
cmd.CommandType = CommandType.Text;
using (SQLiteDataReader rdra = cmd.ExecuteReader(CommandBehavior.CloseConnection))
{
try
{
while (rdra.Read())
{
textBox1.Text = rdra["question"].ToString();
idintrebare = Convert.ToInt32(rdra["id"]);
}
rdra.Close();
}
catch (InvalidOperationException ex)
{
MessageBox.Show(ex.Message);
}
}
}
}
}
Function where is the problem (I guess):
private void updateIndex()
{
string update = "UPDATE questions SET indexrow='" + idintrebare + "' WHERE id='" + idintrebare + "'";
SQLiteCommand comp = new SQLiteCommand(update, Conexiune.getConnection());
comp.CommandType = CommandType.Text;
comp.Parameters.AddWithValue(idintrebare.ToString(), idintrebare);
SQLiteDataAdapter da = new SQLiteDataAdapter(comp);
DataTable dt = new DataTable();
da.Fill(dt);
}
Button where updateIndex() is called:
private void button1_Click(object sender, EventArgs e)
{
try
{
updateIndex();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
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1) For Insert-, Update- and Delete-Statements you should use the ExecuteNonQuery()-method of the Command-object.
2) Though you initialized an Sql-Parameter and added it to the Command-object, you didn't adjust your Sql-Statement accordingly and you used the value of your variable idintrebare as the name for the parameter.
3) As CommandType.Text is the default, you don't have to explicitly set it.
4) Use disposable objects (the Connection and Command here) in a using-Block. See this Article: IDisposable: What Your Mother Never Told You About Resource Deallocation[^]
5) idintrebare appears to be a class-member. I would suggest you call updateIndex() with idintrebare as an argument instead. As I don't know the type of it, I'll use int here, please adjust that if neccessary.
This should work:
private void updateIndex(int id)
{
string update = "UPDATE questions SET indexrow=@idintrebare WHERE id=@idintrebare;";
using (var connection = Conexiune.getConnection())
using (SQLiteCommand cmd = new SQLiteCommand(update, connection))
{
connection.Open();
cmd.Parameters.AddWithValue("@idintrebare", id);
cmd.ExecuteNonQuery();
}
}
If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson
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First, thank you for suggestions. So: Conexiune is a class. getConnection() is a function that makes the connection and return true if connection is opened. So I can't use that var connection. I used this code in other forms and it worked..I want to update indexrow column with the value of int variable idintrebare..So I rewrite your code like this:
string update = "UPDATE questions SET indexrow=@idintrebare WHERE id=@idintrebare;";
using (var connection = Conexiune.getConnection())
using (SQLiteCommand cmd = new SQLiteCommand(update, connection))
{
connection.Open();
cmd.Parameters.AddWithValue("@idintrebare", idintrebare);
cmd.ExecuteNonQuery();
}
,but I receive Operation is not valid due to the current state of the object.
Conexiune class looks like this: (This is good)
private static string conn = @"Data Source=database.db;Pooling=true;FailIfMissing=false;Version=3;";
public static SQLiteConnection connect = null;
private Conexiune() { }
public static SQLiteConnection getConnection()
{
SQLiteConnection connect = null;
try
{
connect = new SQLiteConnection(conn);
connect.Open();
return connect;
}
catch (SQLiteException e)
{
throw new Exception("Cannot connect", e);
}
}
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getConnection() returns an SQLiteConnection (not true/false).
So you can use that using (var connection = Conexiune.getConnection()) -line.
But as I see in that Conexiune-class, it already opens the connection for you. So the (new) error you're getting probably happens on my connection.Open() -line. Please remove that line and see what happens.
As I've seen from your reply to Richard Deeming, who suggested almost the same new code as me, you still get the old error there. This makes me believe the cause is one of those listed on the page that Simon_Whale linked for you. Do you maybe have an open Select-query while you click on the button that calls updateIndex() ?
If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson
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I removed that line and now database is still locked. Well, I have another function which selects data from table and is called by pressing on another button, but even if I don't press that button and try to call updateIndex() just after form loads, I still got the error..
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Do you possibly have some Select-query that is executed in your program's startup-code (so it get's executed no matter what) ? If yes, you might comment that out for testing. Maybe you don't close the reader of that query properly so that it's still open when trying to execute updateIndex().
If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson
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I am sure..Where I have used DataReader, I used CommnadBehavior.CloseConnection and after that I closed the reader. For example:
string selectareLicenta = "SELECT licenta FROM licente WHERE licenta = '" + maskedTextBox1.Text + "'";
using (SQLiteCommand cmd = new SQLiteCommand(selectareLicenta, Conexiune.getConnection()))
{
using (SQLiteDataReader read = cmd.ExecuteReader(CommandBehavior.CloseConnection))
{
if (read.Read())
{
SimulatorManager.Licenta = read["licenta"].ToString();
}
read.Close();
}
}
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I don't think this is the issue but for good practice you should change this like so:
string selectareLicenta = "SELECT licenta FROM licente WHERE licenta = '" + maskedTextBox1.Text + "'";
using (SQLiteConnection conn = Conexiune.getConnection())
using (SQLiteCommand cmd = new SQLiteCommand(selectareLicenta, conn))
using (SQLiteDataReader read = cmd.ExecuteReader(CommandBehavior.CloseConnection))
{
if (read.Read())
{
SimulatorManager.Licenta = read["licenta"].ToString();
}
}
..and you also should use an Sql-Parameter here.
Regarding the actual problem: I would suggest you double-check that all parts of your code where you run a select-query look like the above to ensure that the reader and connection get properly closed.
For the purpose of testing you could execute an update-statement as the very first action in your program and see if that works.
If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson
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Very good idea, I will try it right now!
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I tried to run the update on form loading and I get the error. It means that the error can be from the form that opens this form? Because I checked there and I have used using for everything and is ok..
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Hmm. And there's nothing database-related happening before that in your code?
Could probably another program be running and accessing the same database? Maybe there's some "zombie"-process of your program still running and keeping a connection to the database alive. See if rebooting Windows solves the issue.
If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson
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It's ok, I have found the error! In class cs where I have static void Main(), this is the main class of the project, I have this code:
string selectutilizator = "SELECT * FROM accounts";
using (SQLiteCommand selcom = new SQLiteCommand(selectutilizator, Conexiune.getConnection()))
{
using (SQLiteDataReader read = selcom.ExecuteReader())
{
if (read.HasRows)
{
Application.Run(new Elev());
}
else Application.Run(new Intro());
}
}
But I need this for the program..what is wrong there?
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Yep, that's the problem, most certainly. Application.Run(..) is a blocking call, so the DataReader is alive all the time. Just declare a boolean variable hasRows at the top of this code, assign read.HasRows to it after ExecuteReader(), move the if-else out of the using-blocks and use the boolean variable there instead of the reader.
If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson
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Yes, you right. Thank you very much! This is the solution:
string selectutilizator = "SELECT * FROM accounts";
bool hasrows=false;
using (SQLiteCommand selcom = new SQLiteCommand(selectutilizator, Conexiune.getConnection()))
{
using (SQLiteDataReader read = selcom.ExecuteReader())
{
if (read.HasRows)
{
hasrows=true;
}
}
}
if (hasrows) Application.Run(new Elev());
else Application.Run(new Intro());
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DPaul1994 wrote: Yes, you right. Thank you very much!
You're welcome! 
If the brain were so simple we could understand it, we would be so simple we couldn't. — Lyall Watson
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Your code is vulnerable to SQL Injection[^].
NEVER use string concatenation to build a SQL query. ALWAYS use a parameterized query.
private void updateIndex()
{
const string update = "UPDATE questions SET indexrow = @idintrebare WHERE id = @idintrebare";
using (SQLiteCommand comp = new SQLiteCommand(update, Conexiune.getConnection()))
{
comp.CommandType = CommandType.Text;
comp.Parameters.AddWithValue("@idintrebare", idintrebare);
comp.ExecuteNonQuery();
}
}
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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