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Keydown event how to listen with hotkey

I have registed ctrl+` as a hotkey,and I want to display a window when I press the hotkey and not release the leftctrl key and toggle ` key to do something else just like alt+tab switch the application.Here is the code.
private void ListOnKeyDown(object sender, KeyEventArgs e)
{
if (e.SystemKey==Key.LeftCtrl && e.Key == Key.Oem3)
{
m_host.SelectNext();
}
}
But I found this way only fired one key.So what's the right way to fire the key event?
And here is the debug information.
debug information

Just change your keydown event to detect the modifier this way
private void ListOnKeyDown(object sender, KeyEventArgs e)
{
if (Keyboard.Modifiers == ModifierKeys.Control && e.Key == Key.Oem3)
{
m_host.SelectNext();
e.Handled = true;
}
}

Because onKeyDown event works for ONE key only, in order to use two keys at same time you need little improvise:
bool firstkeyisOn = false;
private void ListOnKeyDown(object sender, KeyEventArgs e)
{
if (e.SystemKey==Key.LeftCtrl/*Or other key by choice*/)
{
firstkeyisOn = true;
e.Handled = true;
return;
}
if(firstkeyisOn && (e.Key == Key.Oem3/*Or other key by choice*/))
{
m_host.SelectNext();
}
}
private void ListOnKeyUp(object sender, KeyEventArgs e)
{
if (e.SystemKey==Key.LeftCtrl/*Key must be same as holding one*/)
{
firstkeyisOn = false;
}
//or
//firstkeyisOn = false;
}
To cancel hotkey mode you just add firstkeyisOn = false under OnKeyUp event and you good to go.

how to detect two hot key in win form app like CTRL +C , CTRL+ W

my question is how to detect two hot keys in win form application
CTRL +C,CTRL,K like visual studio commenting command
I need to simulate VS hot key For commenting a line of code

private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Modifiers == Keys.Control && e.KeyCode == Keys.C)
{
}
}

Simple way is... There is a Windows API Function called ProcessCmdKey, by overriding this function we can achieve what we want
protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
if (keyData == (Keys.Control | Keys.C)) {
MessageBox.Show("You have pressed the shortcut Ctrl+C");
return true;
}
return base.ProcessCmdKey(ref msg, keyData);
}
Microsoft Documentation can be found here
source

private bool _isFirstKeyPressedW = false;
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control & e.KeyCode == Keys.W)
{
_isFirstKeyPressedW = true;
}
if (_isFirstKeyPressedW)
{
if (e.Control & e.KeyCode == Keys.S)
{
//write your code
}
else
{
_isFirstKeyPressedW = e.KeyCode == Keys.W;
}
}
}

if you want to handle Ctrl + C followed by Ctrl+ K you need to maintain a state variable.
Set the Form KeyPreview property to true and handle the Form KeyDown event.
Try This:
this.KeyPreview=true;
private bool isFirstKeyPressed= false;
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.Control && e.KeyCode == Keys.C)
{
isFirstKeyPressed = true;
}
if (isFirstKeyPressed)
{
if (e.Control && e.KeyCode == Keys.K)
{
MessageBox.Show("Ctrl+C and Ctrl+K pressed Sequentially");
/*write your code here*/
isFirstKeyPressed= false;
}
}
}

Trying to detect keypress

I made a method that detects when a key is pressed, but its not working! Heres my code
void KeyDetect(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.W && firstload == true)
{
MessageBox.Show("Good, now move to that box over to your left");
firstload = false;
}
}
I also tried to make a keyeventhandler but, it sais "cannot assign to key detect because it is a method group"
public Gwindow()
{
this.KeyDetect += new KeyEventHandler(KeyDetect);
InitializeComponent();
}

Use keypress event like this:
private void Form1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyCode == Keys.F1 && e.Alt)
{
//do something
}
}

1) Go to your form's Properties
2) Look for the "Misc" section and make sure "KeyPreview" is set to "True"
3) Go to your form's Events
4) Look for the "Key" section and double click "KeyDown" to generate a function to handle key down events
Here is some example code:
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
Console.WriteLine("You pressed " + e.KeyCode);
if (e.KeyCode == Keys.D0 || e.KeyCode == Keys.NumPad0)
{
//Do Something if the 0 key is pressed (includes Num Pad 0)
}
}

You are looking for this.KeyPress. See How to Handle Keypress Events on MSDN.

Try to use the KeyDown event.
Just see KeyDown in MSDN

Just do
if (Input.GetKeyDown("/* KEYCODE HERE */"))
{
/* CODE HERE */
}

Why does this code only work in one instance?

I've set my form's KeyPreview property to true.
I've added this code:
private void PlatypusScheduleForm_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.F9)
{
tabControlPlatypi.SelectedTab = tabPageDuckBill;
}
else if (e.KeyCode == Keys.F10)
{
tabControlPlatypi.SelectedTab = tabPagePlatypus;
}
}
When I mash F10, it works as expected; mashing F9, however, does nothing.
tabPageDuckBill is the design-time/default tabPage that displays. Why would F10 work in taking me to the "other" tab page, but F9 then not go back to the original?

I found that if I just did this:
private void Form1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.F9)
{
tabControl1.SelectedTab = tabPage1;
e.SuppressKeyPress = true;
}
else if (e.KeyCode == Keys.F10)
{
tabControl1.SelectedTab = tabPage2;
e.SuppressKeyPress = true;
}
}
it'll toggle back and forth just fine. Without that e.SuppressKeyPress = true;, however, it exhibited the behavior you mentioned.

I ran into this same problem in the past, and the problem persisted even after removing suspect code from the SelectedIndexChanged() event. I then used a different techniques that worked much better. Instead of using the form KeyDown event, I overrode the form ProcessCmdKey event as follow:
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (keyData == Keys.F9)
{
this.tabControl1.SelectedTab = tabPage1;
return true;
}
else if (keyData == Keys.F10)
{
this.tabControl1.SelectedTab = tabPage2;
return true;
}
return base.ProcessCmdKey(ref msg, keyData);
}

How can I determine in KeyDown that Shift + Tab was pressed

How can I determine in KeyDown that ⇧ + Tab was pressed.
private void DateTimePicker_BirthDate_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Tab && e.Modifiers == Keys.Shift)
{
//do stuff
}
}
can't work, because never both keys are pressed exactly in the same second. You always to at first the Shift and then the other one..

It can't work, because never both keys are pressed exactly in the same second.
You're right that your code doesn't work, but your reason is wrong. The problem is that the Tab key has a special meaning - it causes the focus to change. Your event handler is not called.
If you use a different key instead of Tab, then your code will work fine.
If you really want to change the behaviour of Shift + Tab for one specific control, it can be done by overriding ProcessCmdKey but remember that many users use the Tab key to navigate around the form and changing the behaviour of this key may annoy those users.
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
if (DateTimePicker_BirthDate.Focused && keyData == (Keys.Tab | Keys.Shift))
{
MessageBox.Show("shift + tab pressed");
return true;
}
else
{
return base.ProcessCmdKey(ref msg, keyData);
}
}

If you are looking for a key press combination (Tab, then Shift) like Ctrl K + D you will have to use this modified example which was taken from MSDN social.
private StringBuilder _pressedKeys = new StringBuilder();
private void DateTimePicker_BirthDate_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Tab)
{
_pressedKeys.Append("Tab");
return;
}
if (e.Modifiers == Keys.Shift)
{
_pressedKeys.Append("Shift");
return;
}
if (_pressedKeys.ToString()."TabShift")
{
MessageBox.Show("It works!");
_pressedKeys.Clear();
}
else
{
_pressedKeys.Clear();
}
base.OnKeyDown(e);
}

First hook the Tab keypress event, then during the event, check the state of the Shift key. Keep in mind that there are two shift keys; make sure you check both of them.
This very related post shows how to check the state of modifier keys:
How to detect the currently pressed key?
Edit: an insight provided by another answerer who justly deserves an upvote is that the default behavior of the tab key (to change control focus) must be suppressed.

You can find your answer in
this post

It's Simple.
You can do that using KeyUp Event in the TextBox
private void txtBox1_KeyUp(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Tab && e.Shift == false) // TAB Key Pressed
{
}
if (e.KeyCode == Keys.Tab && e.Shift == true) // TAB + SHIFT Key Pressed
{
}
}
Or
Using this you can identify Any Key is press inside the form
//Add This code inside the Form_Load Event
private void Form1_Load(object sender, EventArgs e)
{
this.KeyUp += new System.Windows.Forms.KeyEventHandler(KeyPressEvent);
this.KeyPreview = true;
}
//Create this Custom Event
private void KeyPressEvent(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Tab && e.Shift == false) // TAB Key Pressed
{
}
if (e.KeyCode == Keys.Tab && e.Shift == true) // TAB + SHIFT Key Pressed
{
}
}

It's Simple.
Using this you can identify Any Key is press inside the form
//Add This code inside the Form_Load Event
private void Form1_Load(object sender, EventArgs e)
{
this.KeyUp += new System.Windows.Forms.KeyEventHandler(KeyPressEvent);
this.KeyPreview = true;
}
//Create this Custom Event
private void KeyPressEvent(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Tab && e.Shift == false) // TAB Key Pressed
{
}
if (e.KeyCode == Keys.Tab && e.Shift == true) // TAB + SHIFT Key Pressed
{
}
}