ASP.NET中的多选下拉列表

Question

Do any good multi-select dropdownlist with checkboxes (webcontrol) exist for asp.net?

Thanks a lot

Answer 1

您可以使用System.Web.UI.WebControls.CheckBoxList控件或使用System.Web.UI.WebControls.ListBox控件，并将SelectionMode属性设置为Multiple 。

Answer 2

jQuery Dropdown Check List can be used to transform a regular multiple select html element into a dropdown checkbox list, it works on client so can be used with any server side technology:

_{(source: googlecode.com )}

Answer 3

试试这个直接从CheckBoxList继承的服务器控件（免费，开源）： http ： //dropdowncheckboxes.codeplex.com/

Answer 4

I've used the open source control at http://dropdowncheckboxes.codeplex.com/ and been very happy with it. My addition was to allow a list of checked files to use just file names instead of full paths if the 'selected' caption gets too long. My addition is called instead of UpdateSelection in your postback handler:

// Update the caption assuming that the items are files<br/> 
// If the caption is too long, eliminate paths from file names<br/> 
public void UpdateSelectionFiles(int maxChars) {
  StringBuilder full = new StringBuilder(); 
  StringBuilder shorter = new StringBuilder();
  foreach (ListItem item in Items) { 
    if (item.Selected) { 
      full.AppendFormat("{0}; ", item.Text);
      shorter.AppendFormat("{0}; ", new FileInfo(item.Text).Name);
    } 
  } 
  if (full.Length == 0) Texts.SelectBoxCaption = "Select...";
  else if (full.Length <= maxChars) Texts.SelectBoxCaption = full.ToString(); 
  else Texts.SelectBoxCaption = shorter.ToString();
} 

Answer 5

Check this out. It's free one.

http://irfaann.blogspot.com/2009/07/ajax-based-multiselect-dropdown-control.html

HTH,

Answer 6

HTML does not support a dropdown list with checkboxes. You can have a dropdown list, or a checkbox list. You could possibly fake a dropdowncheckbox list using javascript and hiding divs, but that would be less reliable than just a standard checkbox list.

There are of course 3rd party controls that look like a dropdown checkboxlist, but they are using the div tricks.

you could also use a double listbox, which handles multi select by moving items back and forth between two lists. This has the added benefit of being easily to see all the selected items at once, even though the list of total items is long

(Imagine a list of every city in the world, with only the first and last selected)

Answer 7

I like the Infragistics controls. The WebDropDown has what you need. The only drawback is they can be a bit spendy.

Answer 8

Here's a cool ASP.NET Web control called Multi-Select List Field at http://www.xnodesystems.com/ . It's capable of:

(1) Multi-select; (2) Auto-complete; (3) Validation.