Multi-Select List Field - ASP.NET MultiSelect DropDownList with Validation
Do you ever need an ASP.NET MultiSelect DropDownList with validation? Multi-Select List Field
is the answer. Multi-Select List Field respresents a labeled ASP.NET multi-select drop down list
that allows user to select, display and validate multiple items from the autocomplete drop down list.
Implementation
Multi-Select List Field is implemented by the MultiSelectListField class.
Documentation
Click here to see the documentation
of the MultiSelectListField class.
Validations
Multi-Select List Field supports validations in the following execution order.
- Not null validation
- Selected items count validation
- Custom validation
Custom Validation
Multi-Select List Field supports custom validation at both client-side and server-side. To setup
the custom validation error message, use the MultiSelectListField.CustomValidation.Message property;
to setup client-side custom validation, use the MultiSelectListField.CustomValidation.ClientValidator
property to specify the name of a JavaScript function that is used to perform client-side custom validation;
to setup server-side custom validation, handle the server-side CustomValidate event.
The custom client validator function must take one parameter which in run-time will receve the
validation context as a JSON object in the following format:
{"source":listBoxId, "data":selectedItems, "callback":callbackFunction}.
Here the "source" contains the id of the list box (multi-selectable select tag); "data" is an array
that contains the selected option elements in the list box; "callback" contains a function that can be
used during asynchronous custom validation to notify the XField's Client Validation Engine about the
result of the validation.
To perform synchronous custom validation, add validation logic in the custom client validator you
provide, and return a boolean value to indicate whether the field data passes the validation or not.
To perform asynchronous (Ajax) custom validation, first save the callback function somewhere
(typically in a global variable); then setup Ajax call to the server-side to handle custom validation.
After the Ajax call completes, notify the XField's Client Validation Engine about the result of
the validation by invoking the saved callback with a boolean value to indicate whether the
field data passes the validation or not.
Styles / Skin Management
Multi-Select List Field exposes the following properties to allow client to manage its styles or skin.
| Property Name |
Property Type |
Default Value |
Description |
| DataControlsFontFamily |
System.String |
"" |
Gets or sets the font family for the data controls (e.g. "Arial"). |
| DataControlsFontSize |
System.String |
"" |
Gets or sets the font size for the data controls (e.g. "12px"). |
| HideSummary |
System.Boolean |
false |
Gets or sets a value indicating whether the selection summary should be hidden. |
| RemoveButtonText |
System.String |
"Remove" |
Gets or sets the remove button text. |
| SearchBoxWidth |
System.String |
"60px" |
Gets or sets the width of the search box (e.g. "60px"). |
| SelectAllText |
System.String |
"Select All" |
Gets or sets the select all text. |
| SelectedItemsList |
SelectedItemsListStyles |
- SelectedItemsList.BackgroundColor = ""
- SelectedItemsList.DisabledTextColor = "gray"
- SelectedItemsList.ForeColor = ""
- SelectedItemsList.Height = "94px"
- SelectedItemsList.HighlightBackgroundColor = ""
- SelectedItemsList.HighlightForeColor = ""
- SelectedItemsList.MaxWidth = 300
|
Gets the settings that mangages the styles of the selected items list. |
| SelectionPromptText |
System.String |
"Select" |
Gets or sets the selection prompt text. |
| SuggestList |
SuggestListStyles |
- SuggestList.BackgroundColor = ""
- SuggestList.BorderColor = ""
- SuggestList.BorderWidth = ""
- SuggestList.CloseButtonFontSize = "11pt"
- SuggestList.ForeColor = ""
- SuggestList.HighlightBackgroundColor = ""
- SuggestList.HighlightForeColor = ""
- SuggestList.MaxRows = 1000
- SuggestList.MaxVisibleRows = 20
- SuggestList.PageInfoKeyword = "/"
|
Gets the settings that mangages the styles of the suggest list. |
| SummaryPrefix |
System.String |
"" |
Gets or sets the prefix of the selection summary that indicates how many items are selected. |
| SummarySuffix |
System.String |
" selected" |
Gets or sets the suffix of the selection summary that indicates how many items are selected. |
View Custom Validation Demo of Multi-Select List Field.
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