I have a powershell script:
$i = 0
$delay = 1000
while($i -eq 0)
{
$myshell = New-Object -com "Wscript.Shell"
$myshell.sendkeys("q")
Start-Sleep -m $delay
}
It works but instead of sending a key only for a moment, I want to simulate pressing a key for a while, e.g. 1 second.
1 Answer
To send multiple keystrokes to whatever with sendkeys, you can just do this ( no real need for the WScript stuff):
Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.SendKeys]::SendWait('q'*3)
# Results
<#
qqq
#>
If you are trying to do this against a time state, then you need to provide that. So, that means setting up a stopwatch.
An example of a timer with a form:
Add-Type -AssemblyName Microsoft.VisualBasic,
PresentationCore,
PresentationFramework,
System.Drawing,
System.Windows.Forms,
WindowsBase,
WindowsFormsIntegration
$delay = 10
$Counter_Form = New-Object System.Windows.Forms.Form
$Counter_Form.Text = "Countdown Timer!"
$Counter_Form.Width = 450
$Counter_Form.Height = 200
$Counter_Label = New-Object System.Windows.Forms.Label
$Counter_Label.AutoSize = $true
$Counter_Form.Controls.Add($Counter_Label)
while ($delay -ge 0)
{
$Counter_Form.Show()
$Counter_Label.Text = "Seconds Remaining: $($delay)"
start-sleep 1
$delay -= 1
}
$Counter_Form.Close()
Using a timer object, a short example:
$Timer = New-Object system.diagnostics.stopwatch
$Timer.Start()
Start-Sleep -Milliseconds 1001
$Timer.Stop()
$timer
# Results
<#
IsRunning Elapsed ElapsedMilliseconds ElapsedTicks
--------- ------- ------------------- ------------
False 00:00:01.0055471 1005 10055471
#>
So, you end up going down the above, with your code.
Add-Type -AssemblyName System.Windows.Forms
$Timer = New-Object system.diagnostics.stopwatch
$Timer.Start()
while ($Timer.ElapsedMilliseconds -le 1000)
{[System.Windows.Forms.SendKeys]::SendWait('q')}
# Results
<#
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
#>
Using a delay/sleep
Add-Type -AssemblyName System.Windows.Forms
$Timer = New-Object system.diagnostics.stopwatch
$Timer.Start()
while ($Timer.ElapsedMilliseconds -le 1000)
{
Start-Sleep -Milliseconds 100
[System.Windows.Forms.SendKeys]::SendWait('q')
}
# Results
<#
qqqqqqq
#>
Update based on SilBee's comment:
Taking action on any keypress.
Add-Type -AssemblyName System.Windows.Forms
$Timer = New-Object system.diagnostics.stopwatch
$Timer.Start()
while ($Timer.ElapsedMilliseconds -le 1000)
{
$Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown") | OUT-NULL
[System.Windows.Forms.SendKeys]::SendWait('q')
Start-Sleep -Milliseconds 100
}
'Done'
$Timer
# Results
<#
Done
IsRunning Elapsed ElapsedMilliseconds ElapsedTicks
--------- ------- ------------------- ------------
True 00:00:02.0041171 2004 20041490
q
#>
If you are only after a specific key, then the $Host object still provides that.
$Host.UI.RawUI.ReadKey()
# Results
<#
q
VirtualKeyCode Character ControlKeyState KeyDown
-------------- --------- --------------- -------
81 q NumLockOn True
#>
Thus you can code for a specific letter, then branch to whatever other code you choose.
A rough example, could be something like this:
Add-Type -AssemblyName System.Windows.Forms
$Timer = New-Object system.diagnostics.stopwatch
$Timer.Start()
while (($Host.UI.RawUI.ReadKey()).Character -eq 'q')
{
[System.Windows.Forms.SendKeys]::SendWait('q')
Start-Sleep -Milliseconds 100
If ($Timer.ElapsedMilliseconds -ge 5000)
{Break}
}
'Done'
$Timer
# Results
<#
qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqDone
IsRunning Elapsed ElapsedMilliseconds ElapsedTicks
--------- ------- ------------------- ------------
True 00:00:05.0420154 5042 50420519
#>
Again, the above is a user touching the keyboard, not a simulated event.
Trying to simulate that can/will lead to odd results/behavior with SendKeys, without a lot of fine-tuning and involving potentially calls to user32.dll.
It must be remembered, that press and hold is a mechanical action of the keyboard device (signal to the OS via the keyboard driver). There is no such thing in memory, which is where all code is fired.
