Beogradsko programiranje

Verovatno će svako reći da je najbolji način preko Socket-a, koristeći TCP ili UDP za prosledjivanje video strima i pozicija-dogadjaja na tastaturi i mišu.

Mnogo pametniji način koji niko drugi nije pokušao je stalnim snimanjem malih paketa koristeći FTP protokol, koji je u C# neverovatno lako napraviti, čak i ako nemate MS Visual Studio, nego samo CMD prompt i Notepad.

Šta ćemo slati u tim malim paketima-datotekama na FTP server ?

1) Napravimo aplikaciju koja kreira screenshot - snimak ekrana recimo svake sekunde i šalje je na FTP server.

2) Napravimo aplikaciju koja pozicije-dogadjaje na tastaturi i mišu prosledjuje kao TXT datoteke na FTP server. Ovde bi mogli koristiti i web tehnologije npr. ASP/PHP/Ajax za POST/GET na server, ali FTP je mnogo elegantnije rešenje.

3) Treba nam i modul-aplikacija koja generiše događaje miša i njegove pozicije x,y na ekranu, kao i procedura za kreiranje VirtualKeystroke željenih otkucaja na tastaturi, That's all folks !

Zatim integrišimo ove tri funkcionalnosti u jedan BATCH fajl ili neku aplikaciju koju ćemo postaviti na naš "Server" , odnosno "Klijent", plus FTP server koji se koristi kao medju-komunikacioni bafer - prostor, a možete ga zvati i moderno OBLAK.

I sad mi recite, da li Vam zaista treba VNC, RDP ili TeamViewer da bi radili remote od kuće ?

Ostanite kod kuće, happy coding !
primer: https://www.islonline.com/rs/en/

//C#, Get Cursor Pos:
using System.Runtime.InteropServices;
using System.Windows;
// Or use whatever point class you like for the implicit cast operator

/// <summary>
/// Struct representing a point.
/// </summary>
[StructLayout(LayoutKind.Sequential)]
public struct POINT
{
public int X;
public int Y;

public static implicit operator Point(POINT point)
{
return new Point(point.X, point.Y);
}
}

/// <summary>
/// Retrieves the cursor's position, in screen coordinates.
/// </summary>
/// <see>See MSDN documentation for further information.</see>
[DllImport("user32.dll")]
public static extern bool GetCursorPos(out POINT lpPoint);

public static Point GetCursorPosition()
{
POINT lpPoint;
GetCursorPos(out lpPoint);
// NOTE: If you need error handling
// bool success = GetCursorPos(out lpPoint);
// if (!success)

return lpPoint;

}

//C#, Set Cursor Pos:

}
public Int32 x = 0;
public Int32 y = 0;
public Int32 prevx = 0;
public Int32 prevy = 0;
private void Form1_Load(object sender, EventArgs e)
{
timer1.Interval = 1;
timer1.Enabled = true;
x = Cursor.Position.X;
y = Cursor.Position.Y;
prevx = Cursor.Position.X;
prevy = Cursor.Position.Y;

}

private void timer1_Tick(object sender, EventArgs e)
{
x = Cursor.Position.X;
y = Cursor.Position.Y;
textBox1.Text = x.ToString();
textBox2.Text = y.ToString();
if (x > prevx)
{

if (x -prevx > 10)
{
SetCursorPos(x - 9, y);
prevx = x - 9;
}
}
else if (x < prevx)
{
if (prevx-x > 10)
{
SetCursorPos(x + 9, y);
prevx = x - 9;
}

}
///////////////////////////////////
if (y> prevy)
{
if (y -prevy > 10)
{
SetCursorPos(x ,y-9);
prevy = y - 9;
}
}
else if (y < prevy)
{
if (prevy-y > 10)
{
SetCursorPos(x, y+9);
prevy = y - 9;
}

}

//////////////////////////////////
}
}

//MORE GOODIES from C#:

private void MoveCursor()

{

// Set the Current cursor, move the cursor's Position,

// and set its clipping rectangle to the form.

this.Cursor = new Cursor(Cursor.Current.Handle);

Cursor.Position = new Point(Cursor.Position.X - 50, Cursor.Position.Y - 50);

Cursor.Clip = new Rectangle(this.Location, this.Size);

}

//C#, Keyboard Events,

using System;
using System.Runtime.InteropServices;

public class SimulatePCControl
{

[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern void keybd_event(uint bVk, uint bScan, uint dwFlags, uint dwExtraInfo);

private const int VK_LEFT = 0x25;

public static void LeftArrow()
{
    keybd_event(VK_LEFT, 0, 0, 0);
}

}

//C#, Mouse events

using System.Runtime.InteropServices;
using UnityEngine;

public class SimulateMouseClick
{
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern void mouse_event(uint dwFlags, uint dx, uint dy, uint cButtons, uint dwExtraInfo);
//Mouse actions
private const int MOUSEEVENTF_LEFTDOWN = 0x02;
private const int MOUSEEVENTF_LEFTUP = 0x04;
private const int MOUSEEVENTF_RIGHTDOWN = 0x08;
private const int MOUSEEVENTF_RIGHTUP = 0x10;

public static void Click()
{
    //Call the imported function with the cursor's current position
    uint X = (uint)0;
    uint Y = (uint)0;
    mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, X, Y, 0, 0);
    Debug.LogError("SIMULATED A MOUSE CLICK JUST NOW...");
}

//...other code needed for the application
}

//C# Mouse and Keyboard hooks out of form:

https://github.com/gmamaladze/globalmousekeyhook

https://stackoverflow.com/questions/19171081/how-can-i-capture-a-key-press-outside-of-the-form

using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;

class InterceptKeys
{
    private const int WH_KEYBOARD_LL = 13;
    private const int WM_KEYDOWN = 0x0100;
    private static LowLevelKeyboardProc _proc = HookCallback;
    private static IntPtr _hookID = IntPtr.Zero;

    public static void Main()
    {
        _hookID = SetHook(_proc);
        Application.Run();
        UnhookWindowsHookEx(_hookID);
    }

    private static IntPtr SetHook(LowLevelKeyboardProc proc)
    {
        using (Process curProcess = Process.GetCurrentProcess())
        using (ProcessModule curModule = curProcess.MainModule)
        {
            return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
                GetModuleHandle(curModule.ModuleName), 0);
        }
    }

    private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam);

    private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
    {
        if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
        {
            int vkCode = Marshal.ReadInt32(lParam);
            Console.WriteLine((Keys)vkCode);
        }

        return CallNextHookEx(_hookID, nCode, wParam, lParam);
    }

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    private static extern bool UnhookWindowsHookEx(IntPtr hhk);

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern IntPtr GetModuleHandle(string lpModuleName);
}

//C#, retreive keystrokes from hook:

using System;
using System.Diagnostics;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.IO;
class InterceptKeys
{
private const int WH_KEYBOARD_LL = 13;
private const int WM_KEYDOWN = 0x0100;
private static LowLevelKeyboardProc _proc = HookCallback;
private static IntPtr _hookID = IntPtr.Zero;
public static void Main()
{
var handle = GetConsoleWindow();
// Hide
ShowWindow(handle, SW_HIDE);
_hookID = SetHook(_proc);
Application.Run();
UnhookWindowsHookEx(_hookID);
}
private static IntPtr SetHook(LowLevelKeyboardProc proc)
{
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
return SetWindowsHookEx(WH_KEYBOARD_LL, proc,
GetModuleHandle(curModule.ModuleName), 0);
}
}
private delegate IntPtr LowLevelKeyboardProc(
int nCode, IntPtr wParam, IntPtr lParam);
private static IntPtr HookCallback(
int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
int vkCode = Marshal.ReadInt32(lParam);
Console.WriteLine((Keys)vkCode);
StreamWriter sw = new StreamWriter(Application.StartupPath+ @"\log.txt",true);
sw.Write((Keys)vkCode);
sw.Close();
}
return CallNextHookEx(_hookID, nCode, wParam, lParam);
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr SetWindowsHookEx(int idHook,
LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool UnhookWindowsHookEx(IntPtr hhk);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr GetModuleHandle(string lpModuleName);
[DllImport("kernel32.dll")]
static extern IntPtr GetConsoleWindow();
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
const int SW_HIDE = 0;
}

//https://pastebin.com/nPmn7wAW

//C#, Capture Screenshot:

https://www.c-sharpcorner.com/UploadFile/2d2d83/how-to-capture-a-screen-using-C-Sharp/

https://github.com/nishanc/csharp-screenshot-winforms

//C#, Download JPG from URL:

public System.Drawing.Image DownloadImageFromUrl(string imageUrl)
{
System.Drawing.Image image = null;
try
{
System.Net.HttpWebRequest webRequest = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(imageUrl);
webRequest.AllowWriteStreamBuffering = true;
webRequest.Timeout = 30000;
System.Net.WebResponse webResponse = webRequest.GetResponse();
System.IO.Stream stream = webResponse.GetResponseStream();
image = System.Drawing.Image.FromStream(stream);
webResponse.Close();
}
catch (Exception ex)
{
return null;
}
return image;
}

protected void btnSave_Click(object sender, EventArgs e)
{
System.Drawing.Image image = DownloadImageFromUrl(txtUrl.Text.Trim());
string rootPath = @"C:\DownloadedImageFromUrl";
string fileName = System.IO.Path.Combine(rootPath, "test.gif");
image.Save(fileName);
}

https://forgetcode.com/csharp/2052-download-images-from-a-url

using (WebClient client = new WebClient()) 
{
    client.DownloadFile(new Uri(url), @"c:\temp\image35.png");
    // OR 
    client.DownloadFileAsync(new Uri(url), @"c:\temp\image35.png");
}

//the other way:

public void SaveImage(string filename, ImageFormat format)
{    
    WebClient client = new WebClient();
    Stream stream = client.OpenRead(imageUrl);
    Bitmap bitmap;  bitmap = new Bitmap(stream);

    if (bitmap != null)
    {
        bitmap.Save(filename, format);
    }

    stream.Flush();
    stream.Close();
    client.Dispose();
}

Using it

try
{
    SaveImage("--- Any Image Path ---", ImageFormat.Png)
}
catch(ExternalException)
{
    // Something is wrong with Format -- Maybe required Format is not 
    // applicable here
}
catch(ArgumentNullException)
{   
    // Something wrong with Stream
}

https://stackoverflow.com/questions/24797485/how-to-download-image-from-url

http://www.digitalcoding.com/Code-Snippets/C-Sharp/C-Code-Snippet-Download-Image-from-URL.html

/// <summary>
/// Function to download Image from website
/// </summary>
/// <param name="_URL">URL address to download image</param>
/// <returns>Image</returns>
public Image DownloadImage(string _URL)
{
    Image _tmpImage = null;

    try
    {
        // Open a connection
        System.Net.HttpWebRequest _HttpWebRequest = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(_URL);

        _HttpWebRequest.AllowWriteStreamBuffering = true;

        // You can also specify additional header values like the user agent or the referer: (Optional)
        _HttpWebRequest.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)";
        _HttpWebRequest.Referer = "http://www.google.com/";

        // set timeout for 20 seconds (Optional)
        _HttpWebRequest.Timeout = 20000;

        // Request response:
        System.Net.WebResponse _WebResponse = _HttpWebRequest.GetResponse();

        // Open data stream:
        System.IO.Stream _WebStream = _WebResponse.GetResponseStream();

        // convert webstream to image
        _tmpImage = Image.FromStream(_WebStream);

        // Cleanup
        _WebResponse.Close();
        _WebResponse.Close();
    }
    catch (Exception _Exception)
    {
        // Error
        Console.WriteLine("Exception caught in process: {0}", _Exception.ToString());
        return null;
    }

    return _tmpImage;
}

// Download web image
Image _Image = null;
_Image = DownloadImage("http://www.yourdomain.com/sample-image.jpg");

// check for valid image
if (_Image != null)
{
    // show image in picturebox
    pictureBox1.Image = _Image;

    // lets save image to disk
    _Image.Save(@"C:\SampleImage.jpg");
}

Bitmap myJpeg=(Bitmap) Image.FromFile("myJpegPath");

public void Load(string asFile) {
//--- Because Image keeps th file locked untill the garbage collector
releases it, we have
// to make it released as soon a possible using this trick.
Stream BitmapStream =
System.IO.File.Open(asFile,System.IO.FileMode.Open );
Image imgPhoto = Image.FromStream(BitmapStream);
BitmapStream.Close();

//--- Now the file is beeing released continue using the contents.
mBitmap=new Bitmap(imgPhoto);
}

https://stackoverflow.com/questions/13103682/draw-a-bitmap-image-on-the-screen

Form form = new Form();
form.Text = "Image Viewer";
PictureBox pictureBox = new PictureBox();
pictureBox.Image = YourImage;
pictureBox.Dock = DockStyle.Fill;
form.Controls.Add(pictureBox);
Application.Run(form);

MORE TIPS:

Ista stvar samo sa Lazarus-IDE umesto C#:

https://beogradsko.blogspot.com/2020/04/create-anydesk-and-teamviewer-like-apps.html

https://wiki.lazarus.freepascal.org/MouseAndKeyInput#License

https://beogradsko.blogspot.com/2020/04/post-get-lazarus-ide.html

https://beogradsko.blogspot.com/2018/03/ovo-je-moja-biblioteka-skinuta-sa.html

http://www.porteus.org/info/tips-and-tricks.html

Beogradsko programiranje

beogradsko programiranje

Friday, May 1, 2020

Kako napraviti svoj TeamViewer na najlogičniji način koji niko do sada nije pokušao

Using it

Stvari koje možete da radite dok ste kod kuće - I am committed to being wealthy and I will take fearless action until I Win!