Question

使用以下代码为表单设置热键按下事件，但是当按下热键时，系统会发出警报声，为什么？

此外，如何设置多个修饰键，例如ctrl + alt + shift + Q

$form1_KeyDown = [System.Windows.Forms.KeyEventHandler]{
    #Event Argument: $_ = [System.Windows.Forms.KeyEventArgs]
    if ($_.Alt -and $_.KeyCode -eq 'Q')
    {
        Write-Host 'Alt-Q pressed'
    }
}

Answer 1

我不知道为什么在按下热键时会听到系统提示音，但这可能与将KeyEventHandler添加到表单中的方式有关。

使用$form1.Add_KeyDown({..})不会给我带来任何问题：

$form1.Add_KeyDown({
    # create a small array to capture the modifier keys used
    $modifiers = @()
    if ($_.Shift)   { $modifiers += "Shift" }
    if ($_.Alt)     { $modifiers += "Alt" }
    if ($_.Control) { $modifiers += "Control" }
    # using that array, build part of the output text
    $modkeys = ''
    if ($modifiers.Count) {
        $modkeys = '{0} ' -f ($modifiers -join ' + ')
    }

    # instead of building up a string 'Shift + Control + Alt', like above, you can also use 
    # the $_.Modifiers property and replace the commas by a plus sign like this:
    # $modkeys = $_.Modifiers -replace ', ', ' + '

    # these are the keys you want to react upon as example
    # here all keys pressed simply do the same thing, namely display what was pressed,
    # so we can shorten the code to simply test if any of the keys in the 
    # array correspond with the key the user pressed.

    if ('Q','A','F1','Escape','NumLock' -contains $_.KeyCode) {

        # we create the output string by making use of the '-f' Format operator in POwershell.
        # you can read more about that here for instance:
        # https://social.technet.microsoft.com/wiki/contents/articles/7855.powershell-using-the-f-format-operator.aspx
        Write-Host ('{0}{1} pressed' -f $modkeys, $_.KeyCode)

        # The same could have been done with something like:
        # Write-Host ($modkeys + ' ' + $_.KeyCode + ' pressed')
        # or
        # Write-Host "$modkeys $($_.KeyCode) pressed"
    }
})

设置表单的热键按下事件

1 个答案: