AJAX :: Cascading Dropdown List Where The Number Of Dropdowns Is Created Dynamically On The Page
Mar 7, 2010
I am using cascading dropdown list where the no of dropdowns is created dynamically on the page. The cascading drop downs are contained in a User Control. I need to call a method from the Parent page which will be executed when the values in one of the dropdowns change. The server side event is not firing as I have set AutoPostback property for the dropdownlists to be false. How can i make the Page event fired from the Selected index changed of the dropdowns keeping the autopostback property to be set as false.
I have three cascading dropdowns on my web page and they work fine. The issue I am facing is that there are other controls on the page which cause a postback and with each postback the cascading drop downs are being re-populated (service methods are called) which is becoming a performnace issue.
How can i generate dropdown lists based on what has been selected in the checckbox list. Below is an example of what i need. if the user selects the options day, lotID and waferID, then 3 cascading dropdown lists should be displayed. And then a gridview displays data based on what has been chosen in the dropdown lists.
Day LotID SlotID WaferID VendorID ToolID LocationDetected ProcessStep Stage Precipe WaferStartMaterial WaferStartVendor WaferStartLot WaferDiameterCOA WaferMapTitle BreakPoint BreakpointSide BreakpointMeasurement
I have a Cascading drop down list that is working fine to load the correct lists however I would like to have the last one initiate a query and display a datagrid on the same page containing the results of the query. Without Ajax involved this seems rather easy by using autopostback on the drop downs. If I could do it through Ajax that would be great but I can settle with having the page to reload to display the data. Right now I'm not sure how to do either. I enabled autopostback on the last drop down and wrote a method for it but I get an error at runtime saying:
I have a database with some data in. Now I'm trying to show that data on my page whit a ListView.
For each object from the database a ListView will generate a dropdownlist.
I also have a DataPager on my page and this is where the problem occurs.
Each object generated from the database has a field that may look like this example.: 1,2,3.
In my code now I´m trying to split this string of comma character and add new items to my dropdownlist.
This works as long as I do not have DataPager on. But if I choose to view an x number of pages at the time when the page loads, I have value in the dropdownlists, only on my first page.
I am new to using Ajax Control toolkit. I need to create a dynamic cascading dropdowns in which the no of dropdowns will be programatically decided. Also the last dropdown can be replaced with a listbox as well. how i can leverage the Ajax toolkit's cascading dropdown.
I've 2 dropdownlists, both are binded to a cascadingdropdown. Whenever I select an option in the 1st dropdownlist (parent), the options in the 2nd dropdownlist (child) will repopulate based on the options I selected in the parent dropdownlist. I need a javascript function to reset the options of both dropdownlists in their initial state (the prompt text).
I've tried changing the selectedIndex of the parent dropdownlist. However, this only changes the selected option in the parent dropdownlist. It does not reset the child dropdownlist to its initial state (which is supposed to be disabled and without any options). Need the script to reset the chained dropdownlists?
is there a way to cancel the current selection for a cascadingdropdown list ? For example, user changes selection, I present user with option to cancel selection and if he chooses to cancel, then the old value should be reverted.
I am using the newest AJAX control toolkit. What I want to accomplish is I have a modal popup panel with cascading dropdown list and radio button inside. The issue is the postback. RadioButton and Cascading dropdown have postback so that will cause the modal panel disappear after the postback. I just want the panel disappear after I click the ok button on the panel and send the data into a field in a page. What I did was I placed the update panel inside the popup panel. If I did that, I would see the dropdown lists automatically refresh every time by accessing the webservice. If I placed the update panel outside, the dropdown would not be triggered. Even I set the trigger for the Update Panel, it will not see that way.
i use cascading dropdown lists (in a user registration form) and when the user hits the submit button i get the error: "Invalid postback or callback argument" I've seen on the net that this is a problem dating back many years but still haven't found a solution to this. I've read about changing EnableEventValidation to false, but this poses a security risk.
I've been working on my first version of an ASP.NET app, using cascading dropdowns. I've got 2 dropdowns on a page.
However, the third major control on the page is a details view. It works fantastic, with the cascading dropdowns, to display information from the second dropdown, and allow the user to edit that data. All well and good. But now, in testing, I suddenly realized that I've got no way of displaying the details view if I want to let the user enter new data, which would show some information in the second drop down.
This has totally spoiled my .net 4 vs2010 realease day happiness. Running Cascading dropdowns using 'webservice' asmx method. Everything worked on .3.5 and i solved the running 'code In page' method with this post. Method error 500 [URL] Thought I was sorted but seems the rules are totaly different for the 'webservice method'. For example where did ToolkitScriptManager come from Ive been using ScriptManager for years. Anyway below is the Webservice and Page code. Ive looked at and tried everything of the forum but all of it is pre .4. This is demo code, the real version has 3 dependant dropdowns and the lookups are used several times so it HAS to be a webservice. My current theroies are:
1. Permissions- dosent makes sense. 2. Something missing in web.config to enable webservices. 3. Something to do with placement of 'System.Web.Script.Services.ScriptService()>'
I have 3 dropdowns in my VB.Net 3.5 web app. After a user selects a value from the first (let's call it Countries) the second (called States) should populate correspondingly. Dropdown three (cities) should also cascade down after a State is selected. The Countries and States dropdowns have SQL DataSources. The Cities dropdown has to call 2 procs (based on the selected State value) so it does not have a SQLDataSource. My question is, the code below works for Countries and States, however, I cannot ge the Cities to populate...
<asp:DropDownList ID="drpCountries" runat="server" DataTextField="CountryName" DataValueField="CountryId" DataSourceID="sdsCountries" AutoPostBack="true"> </asp:DropDownList> <asp:SqlDataSource ID="sdsCountries" runat="server" ConnectionString="<%$ ConnectionStrings:MyConnectionString %>" SelectCommand="SELECT * FROM [Countries] ORDER BY [CountryName] ASC"></asp:SqlDataSource> <asp:UpdatePanel ID="updStates" runat="server" UpdateMode="Conditional"> <ContentTemplate> <asp:DropDownList ID="drpStates" runat="server" DataTextField="StateName" DataValueField="StateId" AutoPostBack="true" DataSourceID="sdsStates"> </asp:DropDownList> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="drpCountries" EventName="SelectedIndexChanged" /> </Triggers> </asp:UpdatePanel> <asp:SqlDataSource ID="sdsStates" runat="server" ConnectionString="<%$ ConnectionStrings:MyConnectionString %>" SelectCommand="SELECT * FROM [states] WHERE StateId = @StateID ORDER BY [StateName] ASC"> <SelectParameters> <asp:ControlParameter ControlID="drpCountries" Name="StateID" PropertyName="SelectedValue" DefaultValue="" /> </SelectParameters> </asp:SqlDataSource>
THIS DOES NOT WORK:
<asp:UpdatePanel ID="updCities" runat="server" UpdateMode="Conditional"> <ContentTemplate> <asp:DropDownList ID="drpCities" runat="server" DataTextField="CityName" DataValueField="CityId" AutoPostBack="true"> </asp:DropDownList> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="drpStates" EventName="SelectedIndexChanged" /> </Triggers> </asp:UpdatePanel> Protected Sub drpStates_DataBinding(ByVal sender As Object, ByVal e As System.EventArgs) _ Handles drpStates.DataBinding ' Call some procs and get a DataSet drpCities.DataSource = ds drpCities.DataBind() End Sub
I have three cascading dropdowns and two of them need to trigger something outside of the dropdowns, so I have OnSelectedIndexChanged events on them. So as to not reload the whole page when these items are triggered, I have all of this in an Update Panel.
Everything works fine -- the only issue that the client doesn't like is that the cascading dropdowns reload on the asynchronous postback.
I have a webpage used to document work performed on a job. There can be as many as 6 employees for every line of work documented and I have placed 6 ddl's which are all populated with the same list of employees along with 6 text boxes for the hours. I loop through each ddl in the code behind to add the work performed to the server but I'm thinking there must be a better way to do this. I'll add the code for the first two ddl's so you can get an idea of what I need to do.
I am using cascading dropdown, model popup and update panel in my page.
my all drop down are in update panel. now i am retrieving values from the database through data reader and assign value of respective data to the respective control. but control (drop down list) shows "--select--" and not the retrieve value i.e. "Hospital"
I have a form that needs to display 3 dropdown lists, one for my client type, then, based on the selection, my second list shows the clients for that type, and then based on the client name, my third dropdown box shows the contacts for that client. The first dropdown list one being a normal html.dropdownlist, and the other 2 being CascadingDropdownLists.
I have followed Stephen Walther's method 1 located at [URL]. If I select my client type, then my client names in my second dropdown shows perfectly, but when I choose my client name, the third dropdown does not work. When I view my page source, all my contacts are listed in my <select> control, but my dropdown box stays blank. Did anyone ever get a third dropdown to work?
I'm creating an quiz application which queries the database and extracts the questions and choices. I use dynamically created controls such as a checkbox list and fill the values dynamically. How do I do this? Right now I have these functions:
array_random_init(); this creates a 10 element integer array from 1-20 - extract_question(i): this extracts a question indexed at i in DB, I created the controls and set the appropriate text in this function. - validate_question(i); this is called by button_click and validates the question i according to DB.
I understand I have to recreate the controls in Page_init on postback, but what should it look like? Do I need to add "if IsPostBack" in page_init, or do I create the controls in page_init() and reset their properties in page_load when I use extract_question(i)? Also, I cannot seem to clear the selected boxes on postback, I added page directive "enableviewstate=false" but it doesn't work.
I'm trying to follow this article on cascading dropdown list in a GridView control in edit mode (except I'm using C#) [URL] I keep getting this error message "ProjectID is neither a DataColumn nor a DataRelation for table DefaultView."
I tried cascading dropdown in asp.net using ajax. I have tried with 3 dropdown control. The scenario is First dropdown is loaded when page gets loaded and the second dropdown is loaded based on first is selected and thrid dropdown is loaded based on second one selected, now I want to know how do I load third dropdown based on first and second selected value...
and this aspx page [Code].... perhaps i followed this example here http://programming.top54u.com/post/AJAX-Cascading-Dropdown-Example-using-SQL-Database.aspx
it return an error that System.InvalidCastException: unable to cast di object of 'AjaxControlToolkit.CascadingDropDown' on tye 'System.Web.UI.WebControls.DropDownList'.
Suppose parent dropdown is car (Values are car1, car2, car3)and its child is color(for car1 R Y G B, For car2 R Yand for car3 G B).Now on selection of car2 R and Y will appear and select R, then again made the change on car and select car3 then again select is comiing with G and B and select B.
Now if I select again in car, car1 then the child is populating with the values of car1 but it takes the B as a default value as it was previously selected and also present for car1 too.This case is only happen. on select of child value which is availble for both parent selection.
