I have an ascx component, that holds two-level menu, because there are several user types, and the menu needs to be computed on server.
Anyways - I'm also doing the highlighting of current menu item on server (adding a selected class/css to an item). Highlighting with javascript is not good option, because there is content in datagrids, that causes postback and needs to remain the menu in the same position as selected value is.
So I am doing this as some kind of mapping with a hashtable (e.g. pairs (url-of-the-site, menu-item-to-highlight)), and i have to include a mapping for every site my web application contains in order i want to have menus highlighted... so somehow it bothers me that there has to be a better way to do this. are there any better techniques?
A technique I use on my master page/content pages with .NET 2.0 is to have a publicly accessible method called "SetNavigation" that takes a string character that correlates to the hyperlink control I want to highlight. What the method does is set the CSS stylesheet of the specified hyperlink to my "selected" one.
Then in my child pages, in the Page_Load method, I call the SetNavigation method and pass in the link based on the current page I'm on, such as SetNavigation("hypSearch")
I would gather that you could create a similar control on your ASCX control and then have your Page_Load events, or even button click events call the method if so desired.
Related
I am using two tabs in my page like the attached image.
.
Here, after selecting the value in all dropdownlist controls then, i click the generate button. so, the tab is moved from parameter to report. Then again i click the parameter tab. At this time all my dropdown controls shows null value.
but I want all the dropdown values which i selected before.
how can i get the dropdown control values?
It's important to remember that web pages like this are stateless. One request won't remember anything about another request.
So in your situation, you're putting in data, then it sounds like you're clicking a link (or button) that redirects you to another page, then you try and go back to the first one, and it has to fire off yet another request, with no knowledge of the first one's state.
Given that, it seems like you have two primary options (and dozens of others that I won't bother mentioning):
Move the tabs to be on the same page. (My recommendation)
There are lots of controls out there, or you could easily write one yourself, that don't separate tab pages via multiple requests. If you did that, switching tabs wouldn't lose the data.
Add a "save" button, and disable the other tab.
This way, the user actively has to save the data before being able to leave the page via another tab. The biggest issue here comes in the form of usability.
Which one of those you choose is dependent on a number of factors, not the least of which being code maintainability and the size of requests.
I'm working on a project where the page load certain controls depending on the index available. The loading occurs in the page load where the method PopulateSearchField is called.
Within this method, all the UserControl are added on the page using : Page.LoadControl("path");
The page load and all the required controls are on the page. My problem is when the user click on the Search button the event is triggered and a query is built based on the user input int those controls. Unfortunately, the method isn't able to produce a proper query as it is unable to find any of the controls on the page.
With a temporary ControlCollection variable, I've been able to see that the number of controls on my page is 3 when it should be something from 4 to 10. Those 3 controls in the collection are the static label and buttons on the page.
I don't know if something is wrong with the code or if it's a page cycle problem as this solution used to work on framework 1.1. Yeah, I know this isn't the best thing to do so, but they did it this way and I gotta make it work.
I'm not sure if it is the migration that has caused the problem or not.
Thanks a lot, David!
When you click the button, the controls are no longer available server side when your click handler is being processed. The page, server side, has no knowledge of the controls you created dynamically since there are no server side controls for the posted values to map to. If you want to find the values, you need to inspect the posted control data and not rely on the server side asp.net control heirarchy.
You could also write all the data you require to a hidden field via javascript and then read the hidden data server side since it will will be posted.
The following is occuring:
Creating controls dynamically
Posting controls data on click
ASP.NET maps the data to the existing controls it knows about.
Your controls are not found so the data is no mapped to anything.
You need to add your controls before the mapping occurs (in PreInit). Check out the Page Lifecycle and you will see how it ties all the controls and data together.
Are you re-adding the controls to the new page when the user clicks search?
Remember... every time the user hits your server for that page... a new Page object is created. If you're dynamically adding controls, you have to do it every time the page loads.
Additionally, since you seem to want to get values out of the controls, you're going to have to make sure that the controls are created with the exact same ID property every time, and created before viewstate is loaded, if you want them to retain their values.
We have a win application that shows a web form in a web browser.
In order to get data from this web form we are using a hidden text box and get its text using HtmlDocument object of web browser control.
I want to make an abstraction of this web form that has this text box element so that other forms can use this abstraction.
I made a web control and put the text box on it.I thought that if I put this control on my page it would have the text box.When i ran my application I noticed that the text box had been rendered but had its control name in its name (WebControl$TextBoxName) and its id(WebControl_TextBoxName) and the win app throw an exception since it couldn't find the element by its id(TextBoxName).
So here's my question:
How can I make an abstract web form/web control that has some elements on it and I can use it to make my final forms have these elements on them? (their names and ids should not be changed)
Thank you for your help
dotNet 4.0 supports static id's so they don't get mangled, read up on Client Id Mode
Alternatively, you could override the render of your control to output a standard html hidden form field with whatever ID you want, and then also add a custom property that will return the textbox that will hide the fact that it isn't an asp.net server control.
Though I've never used the browser control in WinForms, I think what you want to use is a Master Page. Assuming what you're rendering in the browser control is an ASPX page, create a Master Page with the hidden text box that you want to grab your data from, and tell all of the pages you want to have that common control on to use your Master Page. When the page renders, the control id will then be "ctl00_TextBoxName". There is no way of getting around the ID concatenation, since unique IDs are needed and that's the only way to guarantee uniqueness with all the nested control abilities of ASP.NET. However, doing this will guarantee you always have that control named the same on every new form you create that inherits the Master Page. Hope that helps!
In summary (because who reads paragraphs?):
Create Master Page
Place your common control in the Master Page
Have your Form inherit the Master Page
You can read up on how Master Pages work in MSDN's Documentation.
I'm writing an ASP.NET app in which a table of objects is created by the user client-side.
I envisage them clicking "Add item" and a new 'row' is created in the table with textboxes for them to enter their stuff.
I can do this fine by adding HTML with jQuery. The problem is that one of the fields in the row for the user to fill in needs to be a colour picker.
I have an ASP.NET web user control for my colour picker. How do I add an instance of it to the page within my html row? Or am I barking up the wrong tree here - is there a better way of encapsulating the functionality of my colour picker so that it can be put on every row?
No, you can't add a server-side asp.net control to a page that has already been rendered using client-side techniques (aka Javascript)
Two options:
Firstly, switch to using a client-side colour picker. You can then have the data from this included in the post-back by dynamically adding hidden fields to your form.
Secondly, have a single editing panel which includes your colour picker. Users then select a row to edit, which updates the edit panel with current values etc. Values are stored in hidden fields created when you dynamicaly add rows to your table, and included in the post-back
Without seeing your UI, I can't comment as to which would be best. The asp.net control might look nicer, but it might be difficult to work into your design. A pure client-side solution might fit your designer better, but might not look so good. You also need to consider what happens if / when a users adds lots of rows (this might be 10, 50 or 100 depending on your app /code). Lots of dynamically added controls (the first solution) might cripple the performance of the page.
I'm not sure what version of ASP.NET you're using, one approach that would work is to turn your usercontrol into a custom control. You'd then need to implement ICallbackEventHandler (the first way to do Ajax on asp.net); for sure it's a bit more work but it does give you a good level of control.
Alternatively, you could try this
You can't add ASP.NET controls with jQuery (at least not easily). You could, however, perform a postback when you need to add the colour picker to the row.
In the code in front declaratively define a template of what the new row should look like, then hide it using css.
When the user clicks the 'Add new button' select and cloen the contents of your hidden template and write that into your target div. Just make sure to remove the hiding css when you do this.
You will, of course, just be copying the rednered html of your server controls, but htis apporach may give you a quick and easy way of doing what you need
I have a page which is used to display numerous forms for the user to fill out and get reports generated. Each of these forms is inside it's own ASP:Panel control so that I can toggle the visibility of the form (so that only those with appropriate permissions get access to the reports they are allowed to).
The client has now requested a "table of contents" like area on the page with hyperlinks pointing to each of the forms (so that they don't have to spend time scrolling the page to find the particular report form they want). This is easy to accomplish using standard <a href="#Area"> and <a id="Area"> tags. What I am now looking for is a way that would allow me to hide the links of reports that the user does not have access to.
I was first thinking of using the ASP:LinkButton control, but I do not want any postbacks to occur from clicking the links (that would be very unnecessary). Are there any other methods I could use to accomplish the same goal? I am looking for something which would make it easy for me to toggle the visibility of the corresponding link at the same time I am toggling the visibility of the panels containing the report forms (done now from the code-behind).
Note: Using VB as the language
If you use link controls you can just show or hide the link bases on the visibility of its related panel.
Link1.Visible = Panel1.Visible
I was first thinking of using the ASP:LinkButton control, but I do not want any postbacks to occur from clicking the links (that would be very unnecessary)
I disagree. You're talking about redrawing most of the page each time a link is clicked, making a full postback appropriate from a technical standpoint. Additionally, users are conditioned to expect a round-trip to the server when they click on links. That's what a hyperlink normally does. So it's also appropriate from a user-experience standpoint.