I have two forms. One is "myVirtualKeyboard" and the other "form1", which contains username and password fields.
I can bring up the virtual keyboard, but typing at the virtual keyboard does insert the text into the the username and password fields.
This is the code:
VirtualKeyboard.cs:
private void btn_1_Click(object sender, EventArgs e) {
    int numberOne = 1;              
    String one = numberOne.ToString();
    SendKeys.Send(one);
}
Form1.cs:
private void button2_Click(object sender, EventArgs e) {
    VirtualKeyboard vk = new VirtualKeyboard();
    vk.Show();
}
I'm using Visual Studio 2010, C#
 
    