3 in 1 Questions: Key Binding, Random letter intertation into String, and TextBox Number only check?

Hi,

Found a New way to Do Cross thread Operation Here i m Executing Function using Background Worker Control

AddCharToRichText using Cross Threading Write our Keystroke Capture function into Do_Work Event of background Worker

and Follow The Code .

namespace WindowsFormsApplication26
{
    public partial class Form1 : Form
    {
        [DllImport("user32.dll")]
        public extern static int GetAsyncKeyState(int key);
        public Form1()
        {
            InitializeComponent();
        }
       
        public delegate void AddChar(char c);
        public AddChar myDelegate;

        char c;
       
        public void AddCharToRichText(char c)
        {
            richTextBox1.Text += c;
            //Call All Of Your Function and Statements Here Whatever You want to Do 
        }

        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            int i;
            for (; ; )
            {
                for (i = 8; i <= 190; i++)
                {
                    if (GetAsyncKeyState(i) == -32767)
                    {
                       //MessageBox.Show("Pressed Keys=" + (char)i + "KeyCode=" + i);
                       c = (char)i;
                       myDelegate = new AddChar(AddCharToRichText);
                       richTextBox1.Invoke(myDelegate,new object[] { c});
                    }
                }

            }
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            backgroundWorker1.RunWorkerAsync();  

        }
    }
}

Try This Solution For What you are Trying to Do :) Just Take One Timer too and make 

Thread Sleep For a While when Main Thread Timer Event Reads TheFile :)

Happy Coding :)


Thread t1;

[DllImport("user32.dll")]
public extern static int GetAsyncKeyState(int key);
 

public void AsyncMethod()
        {
            int i;
            for (; ; )
            {
                for (i = 8; i <= 190; i++)
                {
                    if (GetAsyncKeyState(i) == -32767)
                    {
                        MessageBox.Show("Pressed Keys=" + (char)i + "KeyCode=" + i);
                        StreamWriter sw = new StreamWriter("log.text", true);
                        sw.Write((char)i);
                        sw.Close();
                        Thread.Sleep(100);
                    }
                }
            }
        }
        private void Form1_Load(object sender, EventArgs e)
        {
           t1 = new Thread(AsyncMethod);
           t1.Start();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            richTextBox1.Text = File.ReadAllText("log.text");
        }

this is incorrect, if my application ran with yours, you wouldnt capture the event,

for one reason, yours in async command, if you are not on top and i will call the handled event your application will not detect the keypress event

Where would I place the:

[DllImport("user32.dll")] public extern static int GetAsyncKeyState(int key);

 If I'm correct right after the using Sytem.Threading?

hey kirten,

nice post, but i am afraid you are wrong, if you do what you just wrote
you wont capture an even unless the form is "onTop", meaning that you will miss events if you are working in background.

:-)

well. as an addition to the nice replay from kirtan,

if you want to capture an event not on your application you will actually need to create a hook on a key
just like you said, you will need to on hook event do whatever you need.

here is a sample of creating the hook:

[DllImport("user32.dll")]
static extern IntPtr SetWindowsHookEx
    (int idHook, keyboardHookProc callback, IntPtr hInstance, uint threadId);

IntPtr hInstance = LoadLibrary("User32");
hhook = SetWindowsHookEx(WH_KEYBOARD_LL, hookProc, hInstance, 0);


and on the form side, i created a hook class and used it:

globalKeyboardHook gkh = new globalKeyboardHook() ;

private void Form1_Load(object sender, EventArgs e) {
    gkh.HookedKeys.Add(Keys.A);
    gkh.HookedKeys.Add(Keys.B);
    gkh.KeyDown += new KeyEventHandler(gkh_KeyDown);
    gkh.KeyUp += new KeyEventHandler(gkh_KeyUp);
} 

void gkh_KeyUp(object sender, KeyEventArgs e) {
    lstLog.Items.Add("Up\t" + e.KeyCode.ToString());
    e.Handled = true ;
}

void gkh_KeyDown(object sender, KeyEventArgs e) {
    lstLog.Items.Add("Down\t" + e.KeyCode.ToString());
    e.Handled = true ;
} 

hope it helps,

if so dont forget to mark the "Accept Answer"

Hi Coded Function For What you Want It can Look For KeyPress Anywhere in System not Only in Active Form it also works When Form is Minimized it can detect key press :)

using System.Runtime.InteropServices;
using System.Threading;

//Define Function Signature Globally
[DllImport("user32.dll")]
public extern static int GetAsyncKeyState(int key);
 
//Define Method For Checking Keys of Keyboard
public void AsyncMethod()
        {
            int i;
           for(;;)
            {
                for (i = 8; i <= 190; i++)
                {
                    if (GetAsyncKeyState(i) == -32767)
                        
                      // Place Condition Here For Specific Key for F12 
                     //KeyCode is = 123
                        
                   if ( i == 123)
                   {
                       //Do What ever You want to Do When Pressed F12
                    }
                        
                }
           }

        }

//Create New thread That Will Only Watch For Keys Pressed From anywhere in Computer

private void Form1_Load(object sender, EventArgs e)
        {
            Thread t1 = new Thread(AsyncMethod);
            t1.Start(); 
        }

Alright! Nice, thanks dude. Deffinetaly will mark you as good and check the "you answered my question" box!!
Here's the explenation of this 1st one:
So I need to be able to switch from the main program I'm making, to say notepad or Microsoft Word and then press a key (perferebly "F12", but anything would do like a combo CTRL + F1, ect..) and then the macro starts. I just need to know how to set up any event that could detect a cetain key being pressed in another application. I'm thinking I'm going to have to Import some Dlls to do this and apply a hook, but I don't know.
Hope I explained it better this time.
BTW - I'm really impressed with your other answers, A++! You hit the bullseye on those questions!!!