How to know if CAPSLOCK key is Up, Down

[wcchan]

Under Platform SDK, we can use GetKeyState. What's under .Net Framework.

Brgds

[Administrator]

I don't see .Net providing a simple way to do this.

So, you have to use the good old GetKeyState directly.

Declare this class first:
[
ComVisibleAttribute(false),
SuppressUnmanagedCodeSecurityAttribute()
]
internal class NativeMethods
{
[DllImport("user32.dll", CharSet=CharSet.Auto, ExactSpelling=true, CallingConvention=CallingConvention.Winapi)]
public static extern short GetKeyState(int keyCode);

public static int HIWORD(int n)
{
return ((n >> 16) & 0xffff/*=~0x0000*/);
}

public static int LOWORD(int n)
{
return (n & 0xffff/*=~0x0000*/);
}
}

Then when you want to check if Caps is down, call:

short state = NativeMethods.GetKeyState(0x14 /*VK_CAPTIAL*/);

bool capsKeyDown = NativeMethods.HIWORD(state);

-Praveen

> Under Platform SDK, we can use GetKeyState. What's under .Net Framework.
>
> Brgds

[Clay Burch]

There is a method for getting modifier key states on the keyboard. It is discussed in our FAQ entry: http://www.syncfusion.com/faq/winforms/search/656.asp

BUT this technique does not work for the CAPS LOCK key. So, the only way I know to get the state of the CAPS LOCK key is to use P/Invoke. Below is some code that seem to work for me.

using System.Runtime.InteropServices;
...
...
[DllImport("user32.dll")] 
public static extern long GetKeyState(int vKey); 

const int VK_CAPITAL = 0x14;

private void button1_Click(object sender, System.EventArgs e)
{
	if( GetKeyState(VK_CAPITAL) != 0)
		Console.WriteLine("the X-CapLock key is down");
}

HTH, Clay Burch

[Administrator]

> I don't see .Net providing a simple way to do this.
>
> So, you have to use the good old GetKeyState directly.
>
> Declare this class first:
> [
> ComVisibleAttribute(false),
> SuppressUnmanagedCodeSecurityAttribute()
> ]
> internal class NativeMethods
> {
> [DllImport("user32.dll", CharSet=CharSet.Auto, ExactSpelling=true, CallingConvention=CallingConvention.Winapi)]
> public static extern short GetKeyState(int keyCode);
>
> public static int HIWORD(int n)
> {
> return ((n >> 16) & 0xffff/*=~0x0000*/);
> }
>
> public static int LOWORD(int n)
> {
> return (n & 0xffff/*=~0x0000*/);
> }
> }
>
> Then when you want to check if Caps is down, call:
>
> short state = NativeMethods.GetKeyState(0x14 /*VK_CAPTIAL*/);
>
> bool capsKeyDown = NativeMethods.HIWORD(state);
>
> -Praveen
>
>
> > Under Platform SDK, we can use GetKeyState. What's under .Net Framework.
> >
> > Brgds