How to know if the keyboard is active on a text input

Question

I have an application that acts like an on screen keyboard, I need it to know if there is a keyboard cursor (caret) active any where, so the keyboard will set to active.

Answer 1

Define a DLLImport so that you can get the currently focused window handle:

[DllImport("user32.dll")]
static extern IntPtr GetFocus();

Now, you can run this to get that window handle if there is something focused for the keyboard:

public static bool ControlIsFocused() 
{
    // To get hold of the focused control: 
    IntPtr focusedHandle = GetFocus(); 
    return focusedHandle != IntPtr.Zero;
}

So, unless it's a control that allows keyboard focus this method should return IntPtr.Zero.

Here is a link to the Windows API.