C# text import from external window

Question

I'm working on an existing project that has a text import tool written in C#. It essentially shuffles to the last window that had focus, copies the text, switches back and pastes the text in the textbox. To do this it essentially issues keyboard commands so: "Alt+Tab", "Ctrl+A", "Ctrl+C", "Alt+Tab" and then finally get the text from the clipboard and add it to the textbox.

Currently, it works terrific on XP. It doesn't, however, work on Vista/Win 7. It will switch to the new window and that appears to be it but when I go back to the C# it has added whatever was previously in the clipboard (not successfully copying the new text). My guess is that there's some problem telling another window to use the keyboard keys (Select All and Copy).

I have done some moderate searching online and haven't really found anything so I was hoping to see if anyone may have had a similar problem.

Answer 1

Assuming you're using SendKeys, you might want to look at this comment on the SendKeys MSDN page. If this is something introduced with Vista, it'd almost certainly affect Windows 7 as well, Id' think:

Note

The SendKeys class has been updated for the .NET Framework 3.0 to enable its use in applications that run on Windows Vista. The enhanced security of Windows Vista (known as User Account Control or UAC) prevents the previous implementation from working as expected.

The SendKeys class is susceptible to timing issues, which some developers have had to work around. The updated implementation is still susceptible to timing issues, but is slightly faster and may require changes to the workarounds. The SendKeys class tries to use the previous implementation first, and if that fails, uses the new implementation. As a result, the SendKeys class may behave differently on different operating systems. Additionally, when the SendKeys class uses the new implementation, the SendWait method will not wait for messages to be processed when they are sent to another process.

If your application relies on consistent behavior regardless of the operating system, you can force the SendKeys class to use the new implementation by adding the following application setting to your app.config file.

To force the SendKeys class to use the previous implementation, use the value "JournalHook" instead.

http://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys.aspx