{"id":9921,"date":"2006-07-24T16:12:00","date_gmt":"2006-07-24T16:12:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/powershell\/2006\/07\/24\/casting-a-scriptblock-to-an-arbitrary-delegate-signature\/"},"modified":"2019-02-18T13:21:29","modified_gmt":"2019-02-18T20:21:29","slug":"casting-a-scriptblock-to-an-arbitrary-delegate-signature","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/powershell\/casting-a-scriptblock-to-an-arbitrary-delegate-signature\/","title":{"rendered":"Casting a scriptblock to an arbitrary delegate signature"},"content":{"rendered":"

Arild asked the following in http:\/\/arildf.spaces.msn.com\/blog\/cns!E99F8B43533149B0!140.entry?_c%3dBlogPart<\/a> :<\/p>\n

PSMDTAG:FAQ: Delegates – how to cast a scriptblock to an arbitrary delegate signature? ANSWER – You can’t in V1.0. <\/p>\n

In version 1.0 Windows PowerShell only supports casting scriptblocks to delegates with the signature:<\/p>\n

void Method(Object Sender, object e)<\/p>\n

For instance, here is a WinForms script which uses a scriptblock delegate when a button is clicked:<\/p>\n

  [void][Reflection.Assembly]::LoadWithPartialName(“System.Windows.Forms”)
  $form = new-object Windows.Forms.Form
  $button = new-object Windows.Forms.Button
  $button.Dock = “fill”
  $button.Text = “Click to exit”<\/font><\/p>\n

  ###################################
  # DELEGATE SUPPORT
  ###################################
  $button.add_click(
     {
 write-host @”
`$this is a handle to the button:
      $this”
$($this | out-string)<\/font><\/p>\n

=====================================
`$_ is a pointer to MouseEventArgs:
      $_
$($_ | out-string)
“@ <\/font><\/p>\n

        $form.close()
     }
  )
  $form.Add_Shown(
     {$form.Activate()
     }
  )<\/font><\/p>\n

  $form.controls.add($button)
  $form.showDialog()<\/font><\/p>\n

This works because the delegate for the WinForms button click has the signature that we support in V1.0 (no coincidence there).<\/p>\n

Support for delegates of any signature is definitely something we want to do ASAP (after V1.0).<\/p>\n

Jeffrey Snover [MSFT]
Windows PowerShell\/Aspen Architect
Visit the Windows PowerShell Team blog at:    http:\/\/blogs.msdn.com\/PowerShell<\/a>
Visit the Windows PowerShell ScriptCenter at:  http:\/\/www.microsoft.com\/technet\/scriptcenter\/hubs\/msh.mspx<\/a><\/p>\n

 <\/p>\n

PSMDTAG:DOTNET: Delegate signatures<\/p>\n

h.ps1<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Arild asked the following in http:\/\/arildf.spaces.msn.com\/blog\/cns!E99F8B43533149B0!140.entry?_c%3dBlogPart : PSMDTAG:FAQ: Delegates – how to cast a scriptblock to an arbitrary delegate signature? ANSWER – You can’t in V1.0. In version 1.0 Windows PowerShell only supports casting scriptblocks to delegates with the signature: void Method(Object Sender, object e) For instance, here is a WinForms script which uses a scriptblock delegate when a […]<\/p>\n","protected":false},"author":600,"featured_media":13641,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[53,14,10,54,55],"class_list":["post-9921","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-powershell","tag-delegates","tag-dotnet","tag-faq","tag-scriptblock","tag-winforms"],"acf":[],"blog_post_summary":"

Arild asked the following in http:\/\/arildf.spaces.msn.com\/blog\/cns!E99F8B43533149B0!140.entry?_c%3dBlogPart : PSMDTAG:FAQ: Delegates – how to cast a scriptblock to an arbitrary delegate signature? ANSWER – You can’t in V1.0. In version 1.0 Windows PowerShell only supports casting scriptblocks to delegates with the signature: void Method(Object Sender, object e) For instance, here is a WinForms script which uses a scriptblock delegate when a […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/posts\/9921","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/users\/600"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/comments?post=9921"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/posts\/9921\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/media\/13641"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/media?parent=9921"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/categories?post=9921"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/powershell\/wp-json\/wp\/v2\/tags?post=9921"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}