Web Forms :: Use Validation Control With Dropdownlist?
Jul 19, 2010
I have a Dropdownlist control in my web form with names of few countries pre populated.I have also added a 'Please select..' option in the DDL .Now how to use validation control in DDL so that please select options doesnotget selected when i click submit button.Only after user selects country i want to insert the value in database.
I'm trying to add a validation support to DropDownList by creating a custom control inheriting from DropDownList:
public class MyDropDown: DropDownList, INamingContainer { private const string ValidatorID = "Validator"; private RequiredFieldValidator _validator;
[Code]....
My class implements INamingContainer because I wanted to avoid naming conflicts. Unfortunately when I try using this control I get the following exception:
Unable to find control id 'MDD' referenced by the 'ControlToValidate' property of 'MDD_Validator'
This is happening beause for INamingContainer FindControl(NamingContainerId) returns null.
When I remove INamingContainer implementation and set validator ID in the following way:
I am creating dropdown controls in code behind. in some conditions I need to add validation control to dropdowlist. But Validation not firing when I submit button.
If mQuestion.RequiredToAnswer = True Then Dim mValidator As New RequiredFieldValidator mValidator.ControlToValidate = mDDL.ID mValidator.InitialValue = mDDL.Items(0).Text mValidator.Display = ValidatorDisplay.Dynamic mValidator.ErrorMessage = "* Required!" mTableCell.Controls.Add(mValidator) End If
I have other dropdown controls on aspx page with validation comtrols. Those are working fine. Only when I ddl and validations from code not working?
I had use a combox to let user select staff name and then it will automatically retrive the responsible recommending officer and approving officer to display in other 2 dropdownlist.
my code works fine but when user select staff name each time, the page will reload once to refresh the dropdownlist.
user complaint and don't want the page reload every time, how can i disable the postback? I need to use ajax?
I am using one datalist control for uploading multiple images.I hv used one Asp:FileUplaod Control and one button in one itemtemplate.I am using reqired field validator and regular expression validator for file upload cntrl I am assigning validation group for both of them on ItemDataBound event of my datalist so that each upload cntrl hv same validaton group as required field and regular expression validator.Now what i want to do is - i want to show my error message in validation summary which is right at the top of the page.I want one know how to write javascript that will assign validation group of my control in datalist on which i click ?
I have a dropdownlist (cboViewAlbums) which has displays album values. The first item is a select an album. I am trying to use validation which when lb_create_album linkButton is clicked throws an error if the cboViewAlbums list has the value 0 selected. Below is the code for the this and my attempt:
<asp:DropDownList ID="cboViewAlbums" runat="server" DataSourceID="SqlDataSource1" DataTextField="album_name" DataValueField="album_id" Width="250px" AutoPostBack="True" AppendDataBoundItems="true"> <asp:ListItem Value="0">Please select an album...</asp:ListItem> </asp:DropDownList> <asp:LinkButton ID="lb_create_album" runat="server">Create Album</asp:LinkButton> <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:fpaConnectionString %>" SelectCommand="SELECT [album_id], [album_name] FROM [fpa_albums] ORDER BY [album_name]"> </asp:SqlDataSource> <br /> <asp:HyperLink CssClass="example7" ID="hLinkUploadPhotos" NavigateUrl="multiple_upload.aspx" runat="server">Upload Multiple Photos</asp:HyperLink> <br /> <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="cboViewAlbums" ErrorMessage="Please Select an Album" InitialValue="Please select an album..."></asp:RequiredFieldValidator>
I have Dropdownlist whose value field and text field are bind at runtime. it has --select-- as first item with a value of '0' and the rest of the values are bind at runtime.
I have given validaton group for both the control and the validator as "g1" and Intialvalue=0
But still the page is posting back even if I select '--select--' option.
I'm currently stuck with a problem with MVC2 RC and validation on a dropdownlist :
I have a page with some fields and a dropdownlist. The dropdownlist is not a mandatory field so I would like to save a null value into my property.
Unfortunately, I can't validate my page with a null selected value, because when I look into the modelstate just on the first line of my action, I've already an error telling me I must choose an item.
Is it normal working of dropdownlist validation or is it a bug ?
I'm pretty new to ASP.NET MVC and I'm trying to get my head around how validation of dropdown lists work. I have the following property in my ProfileViewModel class:
[DisplayName("Gender")] public bool? Gender { get; set; }
null is meant to mean "unknown", true female and false male. In the view model constructor I
AllGenders = new List<SelectListItem>(2) { new SelectListItem {Text = "Unknown", Value = "null"}, new SelectListItem {Text = "Male", Value = "false"}, new SelectListItem {Text = "Female", Value = "true"} };
First of all, it seems that I have to use strings when populating a List<SelectListItem>, which feels kinda weird. Is this really how it's done?
Secondly, when I choose "Unknown" in the list the validation fails telling me:
The value 'null' is not valid for Gender.
Why is that? When I remove the "null" option and change Gender to a simple bool, everything seems fine.
I've got a dropdownlist control that the user can select an an employee name and that should then fill in the detailsview control with specific information about that employee.
My dropdownlist control works fine and I do have AutoPostBack set to true. For some reason my detailsview doesn't work. There's no error message. The detailsview control just doesn't show up.
Here's my code:
This is the sqldatasource control for the dropdownlist control:
[Code]....
This is the sqldatasource control for the detailsview control:
I have a required field validator to validate a dropdownlist. this dropdownlist is an autopostback one, and it's causevalidation property is set to be false.the issue is, when I select the default item, the validation message shows, but the still do the postback. And after the postback, the message disappers.here is the snippet of codes:
I have a question regarding validation of drop-down list values. I have a view that is bound to a view model type called ReservationData.
This object contains a property CustomerVehicles of type List<VehicleData>. VehicleDatahas two int properties VehicleMakeId and VehicleModelId.
On my view I am trying to loop over the number of items in the CustomerVehicles collection and displaying two dropdowns for each, a vehicle make dropdown and a vehicle model dropdown usingDropDownListFor.
When I try to submit and validate I do not see any validation errors displayed on the screen.
Just in case you are wondering I have added a ValidationMessageFor for each dropdown as well. I am not sure if this is an issue with the structure of my view model and its complexity and how the controls need to be named or how the ids need to be set.
Here is the code for the looping over the collection:
I'm populating a DropDownList using JS on the client and validating with a RequiredFieldValidator.This works fine on the client but the Page.IsValid consistently comes back false on the server.Is this because the selected value wasn't in the DropDownList when it was first served to the page?What's the easiest way around this? (I need to leave server validation turned on)
I've put a DropDownList control within a LoginView control. I've got 2 SqlDataSource controls outside of the LoginView control, with the intent of databinding the items that comprise the ListItems of the DropDownList control, and another one for the data is stored in another table which has what was previously saved for the selection. However, when I've assign the SqlDataSource control to the DropDownList control's DataSourceID for the lookup table, I'm used to seeing the fields from the SqlDataSource control appearing in the DataTextField and DataValueField properties. However, they're not appearing there at all. Moreover, even when I try to type them in, its as if VS 2010 refuses to allow them.
I'm using Data Annotations to validate my fields, Eventhough field is marked with Required Attribute the DropdownList/ListBox Value doesn't fire up to show they are required. how can I solve this.
I have 2 text boxes in which I am comparing the numeric value of one to the other. At first it works fine and I get the appropriate error message. But eventually as i plug in different numbers although I should be getting an error message I stop getting one. Is there something going on behind the scenes to fire the error message than I am unaware of. Also the error message fires some time when the value is less than the value of another control and equal to the value. I only want it to fire when it is less than the value of the other control.
I hv taken 2 panels one for School transport detail , the other for Personal Transport detail.
The validation controls are different for the panels. When selecting 1st panel the other gets disable and on clicking Save button the error msg of 1st panel appears if not entering proper values. But when 2nd panel I am selecting and without entering any value clicking Save button it still giving error msg of 1st Panel yet it is disabled.