Sendkeys sends no or multiple strings

Question

I made a keyboard in Windows.Forms with many Buttons and the content of them are the different characters of the Alphabet like a real keyboard.

Now the problem is when I am using the Keyboard in Windows 7 everything works perfectly. But when I use the Keyboard on the Touchscreen with Windows XP the keyboard writes multiple times the content of the button I just pressed or does not write anything inside of the textbox.

Here is some example code:

Button temp = sender as Button;
SendKeys.SendWait(temp.Text);

I have tried SendKeys.Flush and the

<appSettings>

<add key="SendKeys" value="SendInput"/>
</appSettings>

inside of the app.config

which is the solution here msdn. But it didnt fix the Problem.

What am I doing wrong?

Edit: Now I found out the first letter always works perfectly. After that everything turns awful. Is there something else than SendKeys.Flush that I could try?

Answer 1

You're losing focus after the first letter... reset focus to the target before calling SendWait.

Answer 2

The sendkeys function really is not the best of functions. Using the winApi and more specifically PostMessage will prove better.

Here is an example : PostMessage WM_KEYDOWN send multiply keys?

You will be working more directly with the message Queue, but it also means that you will have to handle extra things, such as layout/localization.