{"id":70143,"date":"2005-03-29T20:02:00","date_gmt":"2005-03-29T20:02:00","guid":{"rendered":"https:\/\/blogs.technet.microsoft.com\/heyscriptingguy\/2005\/03\/29\/how-can-i-clear-a-list-box-in-an-hta\/"},"modified":"2005-03-29T20:02:00","modified_gmt":"2005-03-29T20:02:00","slug":"how-can-i-clear-a-list-box-in-an-hta","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/scripting\/how-can-i-clear-a-list-box-in-an-hta\/","title":{"rendered":"How Can I Clear a List Box in an HTA?"},"content":{"rendered":"

\"Hey, \n

Hey, Scripting Guy! How can I clear a list box in an HTA?

— AK<\/P>\"Spacer\"\"Hey,\"Script<\/A> \n

Hey, AK. For those of you who aren\u2019t familiar with the term, an HTA – among other things – is a way to use Internet Explorer to provide a graphical user interface for your scripts. (If that still<\/I> doesn\u2019t answer your questions, don\u2019t despair. Instead, stay tuned for April 11th<\/SUP> when we debut our new HTA Developers\u2019 Center.) With an HTA (short for HTML Application<\/I>) you can make your system administration scripts look – and run – like real applications, applications complete with radio buttons, text boxes, check boxes, and, yes, list boxes.<\/P>\n

So suppose you do<\/I> have a list box, one with a bunch of items (technically known as options<\/I>) already in it. In other words, something that looks like this:<\/P>\"Listbox\" \n


Suppose that you want to remove all of those options, leaving you with a nice, clean, empty list box. How can you do that? <\/P>\n

To begin with, as far we know there\u2019s no single command that can clear all the options in a list box. But that\u2019s OK; even if we can\u2019t clear all the options at once, we can<\/I> clear the options one at a time using the RemoveNode<\/B> method. All we have to do is iterate through the all the options in the list box and then delete each one. We can do that by adding a subroutine (in this case, a subroutine named ClearListbox<\/B>) to our HTA:<\/P>

Sub ClearListbox\n    For Each objOption in AvailableOptions.Options\n        objOption.RemoveNode\n    Next \nEnd Sub\n<\/PRE>\n
Note<\/B>. This subroutine assumes that the list box we want to clear is named AvailableOptions<\/B>. <\/P>\n
As you can see, we create a For Each loop that loops through all the Options<\/B> in the list box named AvailableOptions. For each option we find (and, remember, the options correspond to the items in the list box), we call the RemoveNode<\/B> method to remove that option. By the time the For Each loop is done, we will have found – and removed – every item in the list box.<\/P>\n
The only other thing we need to do is add a button to our HTA; this button, when clicked, will call the ClearListbox subroutine. Here\u2019s some HTML that will add a button like this to our HTA:<\/P>
<input id=runbutton  class=”button” type=”button” value=”Clear Listbox” \nname=”run_button”  onClick=”ClearListbox”><p>\n<\/PRE>\n
That\u2019s all we have to do. If we run our revised HTA and click the Clear Listbox<\/B> button, all the options in the list box will be removed, and our HTA will look like this:<\/P>\"Listbox\" \n

Breath-taking, isn\u2019t it?<\/P>\n
If you\u2019d like to try this out for yourself, here\u2019s code that will bring up an HTA with a list box pre-populated with 8 items. Click Clear Listbox<\/B> and all 8 items will be deleted. To use this sample code, copy it, paste it into Notepad, and then save it with a .hta<\/B> file extension (for example, listbox.hta<\/I>). Then just double-click the file in My Computer or Windows Explorer, and see what happens.<\/P>\n
Here\u2019s the HTA code:<\/P>
<html>\n<head>\n<title>Clear a Listbox<\/title>\n<\/head><\/p>\n
<SCRIPT Language=”VBScript”><\/p>\n
Sub ClearListbox\n    For Each objOption in AvailableOptions.Options\n        objOption.RemoveNode\n    Next \nEnd Sub<\/p>\n
<\/SCRIPT><\/p>\n
<body bgcolor=”buttonface”><\/p>\n
<select size=”8″ name=”AvailableOptions” style=”width:400″ >\n<option value=”1″>Option 1<\/option>\n<option value=”2″>Option 2<\/option>\n<option value=”3″>Option 3<\/option>\n<option value=”4″>Option 4<\/option>\n<option value=”1″>Option 5<\/option>\n<option value=”2″>Option 6<\/option>\n<option value=”3″>Option 7<\/option>\n<option value=”4″>Option 8<\/option>\n<\/select><\/p>\n
<p>\n<input id=runbutton  class=”button” type=”button” value=”Clear Listbox” \nname=”run_button”  onClick=”ClearListbox”><p><\/p>\n
<\/body>\n<\/html>\n<\/PRE><\/p>\n","protected":false},"excerpt":{"rendered":"
Hey, Scripting Guy! How can I clear a list box in an HTA?— AK Hey, AK. For those of you who aren\u2019t familiar with the term, an HTA – among other things – is a way to use Internet Explorer to provide a graphical user interface for your scripts. (If that still doesn\u2019t answer your […]<\/p>\n","protected":false},"author":595,"featured_media":87096,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[3,4,5,30],"class_list":["post-70143","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-scripting","tag-scripting-guy","tag-scripting-techniques","tag-vbscript","tag-web-pages-and-htas"],"acf":[],"blog_post_summary":"
Hey, Scripting Guy! How can I clear a list box in an HTA?— AK Hey, AK. For those of you who aren\u2019t familiar with the term, an HTA – among other things – is a way to use Internet Explorer to provide a graphical user interface for your scripts. (If that still doesn\u2019t answer your […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/70143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/users\/595"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/comments?post=70143"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/70143\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media\/87096"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media?parent=70143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/categories?post=70143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/tags?post=70143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}