C# Discussion Boards - CodeProject

6-May-08 11:35

Hi All,

Ive been doing alot of ready about backgroud workers and would like to learn how they work and get one into my small simple application i am building. The problem is that i am finding it hard to understand how to get it into my applciation and how they really work. I was wondering if someone could point me in the direction or even give me an example of it working in my code!

bear in mined that i am a beginner to programming, not just C# so any help would be very much appreciated!

My Port Scanner Application:

[Form1.cs]

using System;<br />
using System.Collections.Generic;<br />
using System.Data;<br />
using System.Drawing;<br />
using System.Text;<br />
using System.Windows.Forms;<br />
using System.Net.Sockets;<br />
using System.IO;<br />
<br />
namespace GUI_Port_Scanner<br />
{<br />
    public partial class Form1 : Form<br />
    {<br />
        string _ip;<br />
        int _startPort;<br />
        int _endPort;<br />
        string fileName = "scan_results.txt";<br />
        TcpClient TcpScan = new TcpClient();<br />
<br />
        public Form1()<br />
        {<br />
            InitializeComponent();<br />
        }<br />
<br />
        private void Form1_Load(object sender, EventArgs e)<br />
        {<br />
            _ip = "";<br />
            _startPort = 0;<br />
            _endPort = 0;<br />
        }<br />
<br />
        private void startScanBtt_Click(object sender, EventArgs e)<br />
        {<br />
            <br />
            if (prevItems.Checked == true)<br />
            {<br />
                listBoxClosed.Items.Clear();<br />
                listBoxOpen.Items.Clear();<br />
            }<br />
<br />
            _ip = hostTxt.Text;<br />
            _startPort = Int32.Parse(startPortTxt.Text);<br />
            _endPort = Int32.Parse(endPortTxt.Text);<br />
<br />
            for (int _currentPort = _startPort; _currentPort <= _endPort; _currentPort++)<br />
            {<br />
                try<br />
                {<br />
                    TcpScan.Connect(_ip, _currentPort);<br />
                    listBoxOpen.Items.Add(" => Port " + _currentPort + " is open.");<br />
                }<br />
                catch<br />
                {<br />
                    listBoxClosed.Items.Add(" => Port " + _currentPort + " is closed.");<br />
                }<br />
            }<br />
<br />
            toFileBtt.Enabled = true;<br />
        }<br />
<br />
        private void toFileBtt_Click(object sender, EventArgs e)<br />
        {<br />
            StreamWriter writeTo = new StreamWriter(fileName, true);<br />
            if (listBoxOpen.Items.Count != 0)<br />
            {<br />
                writeTo.WriteLine();<br />
                writeTo.WriteLine("   Open Ports:");<br />
                writeTo.WriteLine("*-----------------------------*");<br />
            }<br />
            foreach (object item in listBoxOpen.Items)<br />
            {<br />
                writeTo.WriteLine(item.ToString());<br />
            }<br />
            if (listBoxClosed.Items.Count != 0)<br />
            {<br />
                writeTo.WriteLine();<br />
                writeTo.WriteLine("   Closed Ports:");<br />
                writeTo.WriteLine("*-----------------------------*");<br />
            }<br />
            foreach (object item in listBoxClosed.Items)<br />
            {<br />
                writeTo.WriteLine(item.ToString());<br />
            }<br />
            writeTo.Close();<br />
        }<br />
    }<br />
}

[Form1.Designer.cs]

namespace GUI_Port_Scanner<br />
{<br />
    partial class Form1<br />
    {<br />
        /// <summary><br />
        /// Required designer variable.<br />
        /// </summary><br />
        private System.ComponentModel.IContainer components = null;<br />
<br />
        /// <summary><br />
        /// Clean up any resources being used.<br />
        /// </summary><br />
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param><br />
        protected override void Dispose(bool disposing)<br />
        {<br />
            if (disposing && (components != null))<br />
            {<br />
                components.Dispose();<br />
            }<br />
            base.Dispose(disposing);<br />
        }<br />
<br />
        #region Windows Form Designer generated code<br />
<br />
        /// <summary><br />
        /// Required method for Designer support - do not modify<br />
        /// the contents of this method with the code editor.<br />
        /// </summary><br />
        private void InitializeComponent()<br />
        {<br />
            this.hostTxt = new System.Windows.Forms.TextBox();<br />
            this.startPortTxt = new System.Windows.Forms.TextBox();<br />
            this.label1 = new System.Windows.Forms.Label();<br />
            this.label2 = new System.Windows.Forms.Label();<br />
            this.endPortTxt = new System.Windows.Forms.TextBox();<br />
            this.label3 = new System.Windows.Forms.Label();<br />
            this.startScanBtt = new System.Windows.Forms.Button();<br />
            this.listBoxOpen = new System.Windows.Forms.ListBox();<br />
            this.listBoxClosed = new System.Windows.Forms.ListBox();<br />
            this.label4 = new System.Windows.Forms.Label();<br />
            this.label5 = new System.Windows.Forms.Label();<br />
            this.prevItems = new System.Windows.Forms.CheckBox();<br />
            this.toFileBtt = new System.Windows.Forms.Button();<br />
            this.SuspendLayout();<br />
            // <br />
            // hostTxt<br />
            // <br />
            this.hostTxt.Location = new System.Drawing.Point(72, 12);<br />
            this.hostTxt.Name = "hostTxt";<br />
            this.hostTxt.Size = new System.Drawing.Size(196, 20);<br />
            this.hostTxt.TabIndex = 1;<br />
            // <br />
            // startPortTxt<br />
            // <br />
            this.startPortTxt.Location = new System.Drawing.Point(72, 38);<br />
            this.startPortTxt.Name = "startPortTxt";<br />
            this.startPortTxt.Size = new System.Drawing.Size(65, 20);<br />
            this.startPortTxt.TabIndex = 2;<br />
            // <br />
            // label1<br />
            // <br />
            this.label1.AutoSize = true;<br />
            this.label1.Location = new System.Drawing.Point(12, 15);<br />
            this.label1.Name = "label1";<br />
            this.label1.Size = new System.Drawing.Size(32, 13);<br />
            this.label1.TabIndex = 3;<br />
            this.label1.Text = "Host:";<br />
            // <br />
            // label2<br />
            // <br />
            this.label2.AutoSize = true;<br />
            this.label2.Location = new System.Drawing.Point(11, 41);<br />
            this.label2.Name = "label2";<br />
            this.label2.Size = new System.Drawing.Size(54, 13);<br />
            this.label2.TabIndex = 4;<br />
            this.label2.Text = "Start Port:";<br />
            // <br />
            // endPortTxt<br />
            // <br />
            this.endPortTxt.Location = new System.Drawing.Point(203, 38);<br />
            this.endPortTxt.Name = "endPortTxt";<br />
            this.endPortTxt.Size = new System.Drawing.Size(65, 20);<br />
            this.endPortTxt.TabIndex = 5;<br />
            // <br />
            // label3<br />
            // <br />
            this.label3.AutoSize = true;<br />
            this.label3.Location = new System.Drawing.Point(144, 42);<br />
            this.label3.Name = "label3";<br />
            this.label3.Size = new System.Drawing.Size(51, 13);<br />
            this.label3.TabIndex = 6;<br />
            this.label3.Text = "End Port:";<br />
            // <br />
            // startScanBtt<br />
            // <br />
            this.startScanBtt.Location = new System.Drawing.Point(274, 12);<br />
            this.startScanBtt.Name = "startScanBtt";<br />
            this.startScanBtt.Size = new System.Drawing.Size(79, 46);<br />
            this.startScanBtt.TabIndex = 7;<br />
            this.startScanBtt.Text = "Scan";<br />
            this.startScanBtt.UseVisualStyleBackColor = true;<br />
            this.startScanBtt.Click += new System.EventHandler(this.startScanBtt_Click);<br />
            // <br />
            // listBoxOpen<br />
            // <br />
            this.listBoxOpen.BackColor = System.Drawing.SystemColors.MenuText;<br />
            this.listBoxOpen.Font = new System.Drawing.Font("Arial", 9.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));<br />
            this.listBoxOpen.ForeColor = System.Drawing.Color.LimeGreen;<br />
            this.listBoxOpen.FormattingEnabled = true;<br />
            this.listBoxOpen.ItemHeight = 16;<br />
            this.listBoxOpen.Location = new System.Drawing.Point(12, 104);<br />
            this.listBoxOpen.Name = "listBoxOpen";<br />
            this.listBoxOpen.Size = new System.Drawing.Size(168, 164);<br />
            this.listBoxOpen.TabIndex = 8;<br />
            // <br />
            // listBoxClosed<br />
            // <br />
            this.listBoxClosed.BackColor = System.Drawing.SystemColors.MenuText;<br />
            this.listBoxClosed.Font = new System.Drawing.Font("Arial", 9.75F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));<br />
            this.listBoxClosed.ForeColor = System.Drawing.Color.DarkRed;<br />
            this.listBoxClosed.FormattingEnabled = true;<br />
            this.listBoxClosed.ItemHeight = 16;<br />
            this.listBoxClosed.Location = new System.Drawing.Point(186, 104);<br />
            this.listBoxClosed.Name = "listBoxClosed";<br />
            this.listBoxClosed.Size = new System.Drawing.Size(167, 164);<br />
            this.listBoxClosed.TabIndex = 9;<br />
            // <br />
            // label4<br />
            // <br />
            this.label4.AutoSize = true;<br />
            this.label4.Location = new System.Drawing.Point(14, 88);<br />
            this.label4.Name = "label4";<br />
            this.label4.Size = new System.Drawing.Size(63, 13);<br />
            this.label4.TabIndex = 10;<br />
            this.label4.Text = "Open Ports:";<br />
            // <br />
            // label5<br />
            // <br />
            this.label5.AutoSize = true;<br />
            this.label5.Location = new System.Drawing.Point(188, 88);<br />
            this.label5.Name = "label5";<br />
            this.label5.Size = new System.Drawing.Size(69, 13);<br />
            this.label5.TabIndex = 11;<br />
            this.label5.Text = "Closed Ports:";<br />
            // <br />
            // prevItems<br />
            // <br />
            this.prevItems.AutoSize = true;<br />
            this.prevItems.Location = new System.Drawing.Point(73, 65);<br />
            this.prevItems.Name = "prevItems";<br />
            this.prevItems.Size = new System.Drawing.Size(122, 17);<br />
            this.prevItems.TabIndex = 13;<br />
            this.prevItems.Text = "Clear Previous Items";<br />
            this.prevItems.UseVisualStyleBackColor = true;<br />
            // <br />
            // toFileBtt<br />
            // <br />
            this.toFileBtt.Enabled = false;<br />
            this.toFileBtt.Location = new System.Drawing.Point(274, 61);<br />
            this.toFileBtt.Name = "toFileBtt";<br />
            this.toFileBtt.Size = new System.Drawing.Size(79, 23);<br />
            this.toFileBtt.TabIndex = 14;<br />
            this.toFileBtt.Text = "Copy to File";<br />
            this.toFileBtt.UseVisualStyleBackColor = true;<br />
            this.toFileBtt.Click += new System.EventHandler(this.toFileBtt_Click);<br />
            // <br />
            // Form1<br />
            // <br />
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);<br />
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;<br />
            this.ClientSize = new System.Drawing.Size(365, 347);<br />
            this.Controls.Add(this.toFileBtt);<br />
            this.Controls.Add(this.prevItems);<br />
            this.Controls.Add(this.label5);<br />
            this.Controls.Add(this.label4);<br />
            this.Controls.Add(this.listBoxClosed);<br />
            this.Controls.Add(this.listBoxOpen);<br />
            this.Controls.Add(this.startScanBtt);<br />
            this.Controls.Add(this.label3);<br />
            this.Controls.Add(this.endPortTxt);<br />
            this.Controls.Add(this.label2);<br />
            this.Controls.Add(this.label1);<br />
            this.Controls.Add(this.startPortTxt);<br />
            this.Controls.Add(this.hostTxt);<br />
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedToolWindow;<br />
            this.Name = "Form1";<br />
            this.Text = "Input | Output - Port Scanner";<br />
            this.Load += new System.EventHandler(this.Form1_Load);<br />
            this.ResumeLayout(false);<br />
            this.PerformLayout();<br />
<br />
        }<br />
<br />
        #endregion<br />
<br />
        private System.Windows.Forms.TextBox hostTxt;<br />
        private System.Windows.Forms.TextBox startPortTxt;<br />
        private System.Windows.Forms.Label label1;<br />
        private System.Windows.Forms.Label label2;<br />
        private System.Windows.Forms.TextBox endPortTxt;<br />
        private System.Windows.Forms.Label label3;<br />
        private System.Windows.Forms.Button startScanBtt;<br />
        private System.Windows.Forms.ListBox listBoxOpen;<br />
        private System.Windows.Forms.ListBox listBoxClosed;<br />
        private System.Windows.Forms.Label label4;<br />
        private System.Windows.Forms.Label label5;<br />
        private System.Windows.Forms.CheckBox prevItems;<br />
        private System.Windows.Forms.Button toFileBtt;<br />
    }<br />
}<br />

Also any critisism on any other aspect of the program would be great, along with tips and tricks Big Grin | :-D

Thank you very much!

Relentless. Smile | :)

Christian Graus6-May-08 11:38

6-May-08 11:38

Threading is a complex concept to handle early on.

Never post your designer.cs file, the IDE generates that.

I see no progress bar or threading code here. Use the BackgroundWorker class, it's really easy, and it has a report progress event you can use to run a progress bar.

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Relentless6-May-08 11:42

6-May-08 11:42

Thanks for the quick reply,

Noted about the designer.cs file and i have not put any background worker or progress bar in yet, i will do some more research then and get back to you.

Thanks again,
Relentless.

Knowledge is Power.

Gareth H6-May-08 11:59

Gareth H

6-May-08 11:59

Relentless,

Have a read of the below.

http://msdn.microsoft.com/en-us/library/yh598w02(VS.80).aspx[^]

Thus, you could change:

StreamWriter writeTo = new StreamWriter(fileName, true);

using (StreamWriter writeTo = new StreamWriter(fileName, true))
{
 //do stuff
}

Regards,
Gareth.

GuyThiebaut6-May-08 12:24

GuyThiebaut

6-May-08 12:24

Here are a selection of links which helped me learn about threading.

What I would say is don't let what seems like a complex area put you off learning about threading(the basics are just that - basic).
Threading is a basic requirement for decent user interfaces - running processes in the background while allowing the user to still access a form.

Jump in and have fun:

Codeproject threading demonstration
Good General Tutorial on threading
Codeproject sync async threads

Regards

Guy

Continuous effort - not strength or intelligence - is the key to unlocking our potential.(Winston Churchill)

Relentless6-May-08 13:08

6-May-08 13:08

Thank you very muc for your quick replys,

So far i understand that i will need to create a function that will initialize the background worker, i will then need to put the code i want it to do in the background i.e:

for (int _currentPort = _startPort; _currentPort <= _endPort; _currentPort++)<br />
           {<br />
               try<br />
               {<br />
                   TcpScan.Connect(_ip, _currentPort);<br />
                   listBoxOpen.Items.Add(" => Port " + _currentPort + " is open.");<br />
               }<br />
               catch<br />
               {<br />
                   listBoxClosed.Items.Add(" => Port " + _currentPort + " is closed.");<br />
               }<br />
           }

That is as far as i have got thanks a lot for the resorces i will keep reading and playing around with the code. Still a bit confusing.

Relentless.

Knowledge is Power.

Christian Graus6-May-08 13:11

6-May-08 13:11

One important point - you can't manipulate UI stuff in the thread, you need instead to send messages to the Progress event, which runs on the main thread, and can update your UI.

Relentless6-May-08 13:13

6-May-08 13:13

OK thanks again,

Will have to do a lot more reading Smile | :)

thanks again.

Relentless.

Knowledge is Power.

Christian Graus6-May-08 13:24

Writing output in a windows application

6-May-08 13:24

*grin* yeah, there's a number of threading classes, BackgroundWorker definately is the one that makes everything easy for you

Jerry Graham6-May-08 11:21

Jerry Graham

6-May-08 11:21

I have a list and I wish to print the list to the screen or a form in a windows application.
In a console application, I would do it as follows:

foreach ( )
console.Writeline();

I have tried using MessageBox and it shows the list output, but that is not what I want. I want to have the output appear line by line (similar to writeline) and also well formatted.

Could someone point me in the right direction?

Pete O'Hanlon6-May-08 11:28

Pete O'Hanlon

6-May-08 11:28

You could use a ListBox and append the items from the list into the ListBox.

Deja View - the feeling that you've seen this post before.

My blog | My articles

Jerry Graham6-May-08 11:30

Jerry Graham

6-May-08 11:30

Ok Thanks, I will try that. Althought I would think that <cr> might be a problem

Gareth H6-May-08 11:30

Gareth H

6-May-08 11:30

Jerry Graham,

Label listLabel = new Label();
            listLabel.Location = new Point(10, 10);
            listLabel.AutoSize = true;
            foreach (string item in theList)
            {
                listLabel.Text += item + Environment.NewLine;
            }
            
            form.Controls.Add(listLabel);

Something like that?

Regards,
Gareth.

Get mouse coordinates relative to control in separate application...

PIEBALDconsult6-May-08 13:46

PIEBALDconsult

6-May-08 13:46

RichTextBox?

Edmundisme6-May-08 10:40

Edmundisme

6-May-08 10:40

Hello,

I'm wondering how to go about getting the mouse cursor position relative to a child window in a given windows application. I'm writing an application that is interested in this data.

Example: The user clicks a button in some winforms app, and my application uses low level hooks (or some other strategy) to determine the mouse coordinates relative to the clicked button in the other application.

Any thoughts on how to proceed? I'm hooking the mouse so I get the screen coordinates when the mouse is clicked, but I'm not sure how to get position (relative or absolute) of the control that generated the "click" event.

Thanks!

Re: Get mouse coordinates relative to control in separate application...

Christian Graus6-May-08 11:37