How to make a messagebox appear at a specific time

问题:

I want to create an alarm clock that displays a specific event using a messagebox.

Using the code provided:

 [System.Windows.Forms.MessageBox]::Show("Do this task" , "Alert!")  


Do 
{ 
$waitMinutes = 1 
$startTime = get-date 
$endTime   = $startTime.addMinutes($waitMinutes) 
$timeSpan = new-timespan $startTime $endTime 
Start-Sleep $timeSpan.TotalSeconds 

# Play System Sound 
[system.media.systemsounds]::Exclamation.play() 
# Display Message 
Show-MessageBox Reminder "Do this task." 
} 

# Loop until 11pm 
Until ($startTime.hour -eq 23)

回答1:

I think using an event rather than a loop is a much cooler way to do this.

[datetime]$alarmTime = "November 7, 2013 10:30:00 PM" 
$nowTime = get-date 
$tsSeconds = ($alarmTime - $nowTime).Seconds
$timeSpan = New-TimeSpan -Seconds $tsSeconds

$timer = New-Object System.Timers.Timer
Register-ObjectEvent -InputObject $timer -EventName Elapsed -Action { [System.Windows.Forms.MessageBox]::Show("Brush your Teeth" , "Alert!") }
$timer.Autoreset = $false 
$timer.Interval = $timeSpan.TotalMilliseconds
$timer.Enabled = $true

I'm not really in the mood to write you a complete solution because that would be work, and I'm not at work, but I think between all the answers here you've got everything you need.

I referenced this page for guidance on the above:

http://blogs.technet.com/b/heyscriptingguy/archive/2011/06/16/use-asynchronous-event-handling-in-powershell.aspx

回答2:

Try this:

function New-Alarm
{
    param(
        [Parameter(Mandatory=$true,HelpMessage="Enter a time in HH:MM format (e.g. 23:00)")]
        [String]
        $time,

        [Parameter(Mandatory=$true,HelpMessage="Enter the alert box title (e.g. Alert!).")]
        [String]
        $alertBoxTitle,

        [Parameter(Mandatory=$true,HelpMessage="Enter the alert message.")]
        [String]
        $alertBoxMessage
    )

    do 
    {
        Start-Sleep -Seconds 1
    }
    until((get-date) -ge (get-date $time))
    # Play system sound:
    [system.media.systemsounds]::Exclamation.play()
    # Display message
    [System.Windows.Forms.MessageBox]::Show($alertBoxMessage,$alertBoxTitle) 
}

New-Alarm -time "22:00" -alertBoxTitle "Alert!" -alertBoxMessage "Time to study PowerShell!"

回答3:

If you were on V3 I would recommend this (from an elevated/admin prompt):

$principal = New-ScheduledTaskPrincipal -LogonType Interactive
Register-ScheduledJob -Name BrushTeeth -Trigger @{Frequency='Daily';At="7:30am"} -ScriptBlock {
    Add-Type -assembly System.Windows.Forms 
    [Windows.Forms.MessageBox]::Show('Brush your teeth!')}
Set-ScheduledTask -TaskName "\Microsoft\Windows\PowerShell\ScheduledJobs\BrushTeeth" -Principal $principal

Really folks, PowerShell V4 is out now. It's time to move to at least V3. :-)

Note: the $principal business is required to enable the setting "Run only when user is logged on". This allows the UI to interact with the desktop. Without this, now message box appears.