i want to create a web page with a textbox and a gridview.
as you type in the textbox i want the content of grid view to be retrieved from database according to the text of textbox.
i am also using ajax.
is there any way to get the text from textbox as user types in and pass it to the server side code?
i searched on google but the only thing i got was keypress event using jquery or java and display it using java again. but there was nothing about passing it to the code behind.
Thanks and pardon my poor English :(
In asp.net you can specify the AutoPostBack="true" on a textbox this will fire an postback after you lose focus of that TextBox, so not on every keystrike if you desire to have a postback on every keystrike you will have to implement some javascript knowledge.
Here you can find an example:
How do I make a Textbox Postback on KeyUp?
But I believe you are more interessted in a AutoCompleteBox maybe give this link a try:
http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/AutoComplete/AutoComplete.aspx
As you said, you can use the java key press event. Then you can create an ajax request and ask the server for data.
You should make sure that the data you are requesting can be retrieved very fast, otherwise you would have a delay when typing. Maybe it's a better approach to fetch the whole result and filter it while typing.
A small example can be found here: Making a Simple Ajax call to controller in asp.net mvc
Other examples can be found with your friend google.com :-)
Related
I am looking for a textbox in C# which should work like dropdown search values when I type anything in the textbox. Those values will come from calling a method.. and I Should be able to select any of the values.
Do i need to use the asp dropdownlist or is there any other sample code available which could help me.
You should look into jQuery autocomplete feature.
http://jqueryui.com/autocomplete/
The ajax control toolkit provides Autocomplete extender to do just that. The control calls a method, which you specify, asynchronously and get all the values to be shown as an option. I would imagine these values would be retrieved when the page loads and will not be session specific so can be stored in a cache for faster retrieval.
http://www.asp.net/AjaxLibrary/AjaxControlToolkitSampleSite/AutoComplete/AutoComplete.aspx
I have a fairly complex form (user control actually) with one textbox control on it that needs to NOT post back. Is there a way to remove a control from the post? Yes, this textbox is editable.
More info: This is for a credit card processing form, so the "final" submit will post to another site's page. However, prior to this there is plenty of server-side processing that goes on. I know that I can move the the credit card number text box to another page - but this requirement came very late and I'll trying to not have to re-work a lot of things.
The easiest way would be to use an html input as opposed to an ASP TextBox. These are not accessible from code if runat="server" is not set on them.
Or use the viewstate property (http://msdn.microsoft.com/en-us/library/system.web.ui.control.enableviewstate.aspx)
So the situation is that you have a form that is rendered in the user's browser with an action pointing to a different site and you need to make sure that one of the form fields will not be sent when the form is submitted.
Sounds to me like you cannot in that case make absolutely sure that the value is not posted. There are many different possible ways to solve this using javascript (disable input, clear value, etc before submit) but if scripting is turned off I think you're out of luck.
But since you can prepare for sending the form to the other server (change action on form or enable button with PostBackUrl), I guess you could also then set the Enabled property on the textbox to false. That would mean that it can no longer be edited on the final page beforr posting to the other server. Or you could hide the textbox a (so it's not renered at all) and show the field as a label or literal instead.
But even then you still have to somehow make sure the secret value is not included in the viewstate of the form. Which it will be in case you use a label or literal. And also for a textbox that was disabled or hidden on the last postback. Normally the viewstate is just a base64 encoded string so it would be trivial to find the credit card number from there. You could probably fix this by turning off viewstate for the control in question (or even for the whole page) in the last post back to your page before setting the form up for posting to the other server.
If you cannot tell for sure which will be the last postback to your server, then I think you're out of luck without more significant changes. Sorry to be a downer. Some seemingly trivial things are just hard with Asp.Net web forms.
Maybe you could add a separate page that you populate with just the data that you need to send to the other server and have that a sort of "Confirmation page". In that page you could turn off viewstate, show all the data summarized (using labels and literals etc) and the actual data to post could be included in the form as hidden fields. Then that form would post to the other server when the user "Confirms".
How can I create a dynamic drop down list without using AutoPostBack. I ask because I just want to change the value of what the second drop down list displays and then the user clicks a button and it submits. But If I use AutoPostBack then it postbacks to page and runs code that shouldn't be run until that final box has been selected. (I use Postback in the other part of my program so using !IsPostBack isnt a option.) I looked at Javascript but ASP generates all of its controls names at runtime. What can I do? I have looked at the Ajax CascadingDropDown control but my problem with that is it contained in a XML file or a Database, I need this to be contained inside my Page. Any Ideas?
You can use the CascadingDropDown control from the AJAX Control Toolkit
Maybe this example will help? It's part of the ASP.NET AJAX Control Toolkit available here.
You can use AJAX to get the values for the second drop down list, based on the selected value of the first. Add a onchange event handler on the client-side to the first drop down list that makes the AJAX call and fills the second on success.
I have an asp dropdownlist loaded with cities/countries. They are loaded directly in code
<asp:ListItem Value="MIA">Miami, Florida</asp:ListItem>
I would like to extend the control with Ajax in order to allow a user to start typing and show similar matching options from a dropdownlist below. Is this possible using this control and the hard coded values? Thanks!
The behaviour you describe is usually achieved by extending the textbox control rather than dropdownlist.
Microsoft has a lot of useful tutorials on its asp.net website; try this one: http://www.asp.net/AJAX/AjaxControlToolkit/Samples/AutoComplete/AutoComplete.aspx for a start.
If you want to write your own control, I have written a blog about some of the gotchas when adding values to a DropDownList via javascript
http://blog.runxc.com/post/2009/04/27/Using-jQuery-to-add-values-to-a-DropDownList-and-overcoming-ASPNET.aspx
Im trying to emulate a 'find as you type' function like that of the address bar ("awesome bar") in FireFox. I want a suggestion box to appear below a textbox, and the suggestion box contains strings that contain what is in the textbox. I looked at the autocomplete feature of a normal WinForms textbox, but it seems to only search the beginning of the strings.
Has anyone here built or have experience with implementing something like this?
edit:
Some clarification- It is a WinForms project.
It needs to search inside a string, not just the beginning (which is what a normal textbox does if i recall correctly). And the suggestions should be displayed in a popup like a textbox autocomplete.
You need to handle the TextChanged event for your text entry field, and when the text changes, start a new thread running that will apply the new search. If the text changes before you get your results back, just kill the thread. If the thread returns results in time, display them.
You can get slightly more advanced (e.g. wait for a short time after the text changes so that the user can type a word without you triggering off loads of useless threads) but essentially that's it.
There was a discussion earlier on this topic where the author concluded that you are better off doing the whole thing yourself.
How can I dynamically change auto complete entries in a C# combobox or textbox?
I did something vaguely similar, but more like the iTunes® search box than the Awesomebar. My control used the textbox to actively filter a grid; so it wasn't for autocompletion.
...but... basically I had a DataView of all eligible items, whenever the TextBox's Text changed I'd update the Filter to hide all non-matching items. It worked well and might suit your needs for filtering the data--but not sure how to go about using it as an AutoComplete source for the textbox.
I have done such a thing for an app of mine not too much time ago.
What I did is make my search function in a new thread, so every time I typed a new letter, it called the search function in another thread, so I could keep on typing.
I can post some code if you need, but this should be enough to get you started. :)
Hemmed and hawed about deleting this after I noticed the OP edit mentioned winforms, but I think it'll be useful to anyone who comes here looking for the same but for asp.net apps.
Just because nobody has mentioned it yet, for a webforms app you absolutely want to do this with ajax (.net controls or pure JS, your choice). The feature is often called "autocomplete" and the one thing you don't want it to be breaking the seamlessness by making server round trips at the page level.
I suggest you look at this and this.
I've used Search As You Type in C# and How do I make a Textbox Postback on KeyUp?
Basically you use the keyup action to call a postback thats attached to the trigger to the update panel. then you do your update in the textbox_changed event with the dataview or whatever your backend looks like.