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Please indicate the exact error message, as well as the line which is triggering it. "Not working" is not precise enough.
"Five fruits and vegetables a day? What a joke!
Personally, after the third watermelon, I'm full."
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You have a control with the ID ListBoxResults, which will automatically generate a field in your class:
private ListBox ListBoxResults; You have also declared a property called ListBoxResults in your code-behind.
I'd be extremely surprised if that code compiled; if it did, your references to ListBoxResults in your Page_Load method would be referring to the property, not the control.
Remove the property and your code should start working:
namespace Pig
{
public partial class Index : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Driver d1 = new Driver("Hans", "Christensen", 32, "hans@pig.dk", 123456);
Driver d2 = new Driver("Peter", "Jensen", 40, "peter@mail.dk", 123456);
Admin a1 = new Admin("Lene", "Maarud", 55, "lene@pig.dk");
ListBoxResults.Items.Add(d1.ToString());
ListBoxResults.Items.Add(d2.ToString());
ListBoxResults.Items.Add(a1.ToString());
}
}
}
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Okay, I removed the property and also changed "ListBoxResults" to simply "ListBox".
There are some problems remaining.
I will list the errors here (sorry for not doing so at first)
ListBox.Items.Add(d1.ToString());
ListBox.Items.Add(d2.ToString());
ListBox.Items.Add(a1.ToString());
Here I get the error: "An object reference is required for the non-static field, method, or property."
If I remember correctly, a solution to this would be to make a static ArrayList, but I am not sure how I can do it for this code.
Error no. 2
<pre lang="c#">public virtual bool ChangeEmail(string email)
{
Email = email;
return true;
}
Error: "Property or indexer cannot be assigned to -- it is read only"
Error no. 3
public Driver(string v1, string v2, string v3, string v4, string v5)
{
this.v1 = v1;
this.v2 = v2;
this.v3 = v3;
this.v4 = v4;
this.v5 = v5;
}
Error message: There is no argument given that corresponds to the required formal parameter of 'firstName' of 'Person.Person (string, string, int, string)'
Thanks a ton for being patient with me, you guys.
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Member 14671427 wrote: and also changed "ListBoxResults" to simply "ListBox"
Which is not what I said, and is the cause of the "object reference required" errors.
Remove the property; leave the Page_Load method as I showed you:
namespace Pig
{
public partial class Index : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
Driver d1 = new Driver("Hans", "Christensen", 32, "hans@pig.dk", 123456);
Driver d2 = new Driver("Peter", "Jensen", 40, "peter@mail.dk", 123456);
Admin a1 = new Admin("Lene", "Maarud", 55, "lene@pig.dk");
ListBoxResults.Items.Add(d1.ToString());
ListBoxResults.Items.Add(d2.ToString());
ListBoxResults.Items.Add(a1.ToString());
}
}
}
Member 14671427 wrote: Error: "Property or indexer cannot be assigned to -- it is read only"
You haven't added a setter to the Email property, so you can't set it.
If you don't want to be able to change it from outside of the class, then make the setter private:
public string Email { get; private set; }
Member 14671427 wrote: There is no argument given that corresponds to the required formal parameter of 'firstName' of 'Person.Person (string, string, int, string)'
Your Person constructor requires four arguments. Every constructor of a class derived from Person must pass those four arguments into the base constructor.
public Driver(string v1, string v2, string v3, string v4, string v5)
: base("??? FIRST NAME ???", "??? LAST NAME ???", 0, "??? EMAIL ???")
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Hi again and thanks once again.
I did do ask you said. The reason why I tried playing around with the ListBox line is because I am getting an CS0103 error: "The name ListBoxResults does not exist in the current context", which I don't get, because I looked in my index file.
It says
<asp:ListBox ID="ListBoxResults" runat="server" Height="800px" Width="600px"></asp:ListBox>
I checked if the namespace was the issue, but that was not that case.
However, the object reference error is gone, just like you said =)
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That would suggest that your .aspx markup file isn't correctly tied to your .aspx.cs code-behind file.
Check the CodeFile / CodeBehind and Inherits attributes on the <%@ Page ... %> directive in your markup file.
@ Page | Microsoft Docs[^]
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Ah, what an idiot I was. In Inhereits, I had written "index" instead of "Index".
Thanks a lot for helping me =)
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Hi Friends,
I have migrated asp.net 2.0 VS 2005 application to VS 2015 (framework 4.5).
Site loading fine. But when i click on the menus available in the page, actually it is not adding localhost in the redirection url.
for Eg:
My Home Page : http://localhost:1087/CGP/Home/Home.aspx. This page is loading fine.
In this page I have side menus and each menu "Profile" will have hyperlink like : CGP/Emp/Profile.aspx
But when I click on the menu "Profile" it is redirecting to http://CGP/Home/Home.aspx.
The term localhost is missing. I am not sure how to handle this.
Please Suggest.
Thanks and Regards
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We'll probably need to see the code you're using to generate the side menu. But at a guess, you should add "~/" to the start of the URL.
So instead of:
NavigateUrl="CGP/Emp/Profile.aspx" use:
NavigateUrl="~/CGP/Emp/Profile.aspx"
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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.
modified 20-Nov-19 22:29pm.
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Don't post your question in multiple forums. It's annoying, and it's not like people who look at this forum never come in the webdevelopment-forum.
Bastard Programmer from Hell 
If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.
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Hello Friends,
i have following code. I am getting Error "The SqlParameterCollection only accepts non-null SqlParameter type objects, not SqlParameter[] objects."
in the line
cmd.Parameters.Add(HasPermissionParams).
Please help.
Thanks in Advance.
SqlCommand cmd = GetCommand(Sql_GetPermission);
SqlParameter[] HasPermissionParams = GetInsertParameters(Sql_GetPermission);
SetHasPermissionParams(HasPermissionParams, EmpID, Permission);
cmd.Parameters.Add(HasPermissionParams);
private static void SetHasPermissionParams(SqlParameter[] parms, string EmpID, string Permission)
{
parms[0].Value = EmpID;
parms[1].Value = Permission;
}
private const string Sql_GetPermission = "[sp_Permission]";
private static SqlParameter[] GetInsertParameters(string querytype)
{
SqlParameter[] parms = null;
switch (querytype)
{
case Sql_GetPermission:
parms = new SqlParameter[]
{
new SqlParameter("@EmpID", SqlDbType.VarChar),
new SqlParameter("@PermissionName", SqlDbType.VarChar)
};
break;
}
return parms;
}
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I've been developing in ASP.Net for over 12 years and, though it was a bit of a learning curve to start, feel the webforms environment is, for most purposes, pretty good. When MVC came on the scene (first via 3rd parties such as Castle's, then through MS's own offering) everyone pretty much jumped ship declaring it the best thing since sliced bread. As I had a commitment to supporting a number of webforms applications, I didn't initially have any need to switch; and subsequently haven't found any compelling reason to do so. I've looked (briefly, admittedly) at MVC but felt it was a steep learning curve and didn't seem to offer any advantages, and have some actual disadvantages, to what I was used to.
I answered a question in Q+A today where I mentioned Webforms, and the need to decide whether to go webforms or MVC, and a subsequent comment was "I will not recommend webforms".
So I'm curious: what is it about MVC that makes it so much better than webforms? Is it simply that it's flavour of the month and commercial requirements for webforms developers has crashed? (plug: I have a requirement for a webforms maintenance developer ... message me for more details)
Is it that MVC is a lot "better", or do people feel webforms is actively "bad"?
My applications, using webforms, successfully separate business functionality from presentation issues (and indeed database/storage access from business objects). They implement multi-level inheritance, use custom controls to implement standard functionality, incorporate AJAX-based interactive features (not using Microsoft AJAX controls); and have proven to be flexible and extensible. Not yet found anything I can't do with Webforms.
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Guess I must be the biggest opponent of WebForms here, even as far as calling it stupid.
What I didn't like?
Didn't like the way they tried to make it like WinForms, in which objects create HTML. So you create all these labels which are just span tags. Then when you go to port your HTML to another framework, you have to change all the objects back to actual HTML. As a negative effect, you never really master HTML or HTML5. If you stick with WebForms and not move forward, you stay stuck in that world of objects for years, never really moving forward to support phones, tablets and desktops.
I also got burned by the Ajax Control Toolkit. It worked great locally, but failed on long distance connections. The Partial Update control worked the same way. They added so much junk that was never really stable. Perhaps a WebForms app written for in-house use might be OK, but not for world wide production use. And then all of this stuff has to play nice with the Web Server such as IIS. It seems like WebForms with it's ViewState worked tightly with IIS server in order to post data back, and IIS server would have to keep track of every session out there.
Google just didn't play nice with WebForms. WebForms had a way of placing a script on the page, and using a weird URL for it's location that Google didn't like. I think it was a query-string added to the script name. Then Google complained about other elements I had no control over. And then the single use of the Form element, and having to work within that parameter or rule.
I could name probably 10 more things I didn't like about it.
Moving Forward
I dumped WebForms and went MVC, and loved it. After the steep learning curve, I was able to reduce the time for new projects in half. Learned how to write very effective models and are close to my database designs. With views and razor, I was able to create new UI that where more user friendly, and much more fluid. Learned Gulp to package my CSS and compress files.
Then I dumped MVC and went .Net Core MVC loving it even more. Delivering blazing fast speeds but I still didn't care for Razor much. But my SEO tests were off the charts and Google loved it.
Last, I took the Angular jump, Angular wrapped in a .Net Core project. Figured out how to pack all my stuff like SASS, and compile it into a single project that runs in a Docker container. With this technology, I can now focus on providing a great user experience, with super efficient models and database designs, with blazing fast speeds. I spend very time writing code, in which most are just a few lines. I don't have to worry about slow connections any more.
Now I can develop in 1/16 the amount of time it took me in WinForms. My website below is version 298 at the moment. I have no regrets at all about leaving WebForms, even MVC as well. The WebPack train is running and lots of people are hopping on the train.
If it ain't broke don't fix it
Discover my world at jkirkerx.com
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Convincing arguments, and a very nice site that would shame many a company 
..but "There just fine for low volume entry level use in which you get a few visitors a week."? Isn't that "they are just fine"?
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.
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Thanks Eddie!
Maybe I spoke too soon, one of my Docker MongoDB container crashed. First time in 7 months since I figured out how to use Docker that any container has crashed. 7 months uptime is not bad.
If it ain't broke don't fix it
Discover my world at jkirkerx.com
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jkirkerx wrote: Maybe I spoke too soon, one of my Docker MongoDB container crashed.
It's the demo-effect; post a link on CP, and soon you get a lot of posts pointing out what is wrong 
It looks clean, is readable, contains an impressive list of clients and reviews. No weird font/color combinations, not much distractions in animations, and only one popup
Bastard Programmer from Hell
If you can't read my code, try converting it here[^]
"If you just follow the bacon Eddy, wherever it leads you, then you won't have to think about politics." -- Some Bell.
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jkirkerx wrote: Didn't like the way they tried to make it like WinForms,
That was pretty much the design principal. Many people's experience with writing "rich" MS apps was WinForms so they tried to move that stateful, event-driven methodology that people were used to onto the web so there wasn't as much of a learning curve.
jkirkerx wrote: you never really master HTML or HTML5
Because you don't write your own input tags? Input tags are probably 0.001% of html and html5. Like any technology, you can use it in different ways. Apart from the input tag issue you still have to do all the other html and css yourself. Also you don't have to use server controls, there is nothing stopping you using html only if that's your bag, it just means having to manage the state yourself.
jkirkerx wrote: Perhaps a WebForms app written for in-house use might be OK, but not for world wide production use
LOL, ok. Back in the day it was webforms or nothing so trust me, many world wide production apps were using webforms.
jkirkerx wrote: It seems like WebForms with it's ViewState worked tightly with IIS server in order to post data back, and IIS server would have to keep track of every session out there.
You don't seem to understand webforms very well. Of course it is tied to IIS. So? And ViewState is nothing to do with sessions, it's effectively a page-level session that IIS doesn't need to track, so kind of the opposite to what you said. Also Sessions remain in MVC too, they're not a webforms thing either.
jkirkerx wrote: Google just didn't play nice with WebForms
Again, simply not true. Google doesn't really care about your script tags.
jkirkerx wrote: And then the single use of the Form element
Gee, I wonder what I'm going to say here?  You can use as many forms as you want with webforms.
jkirkerx wrote: I dumped WebForms and went MVC...Then I dumped MVC and went .Net Core MVC...Last, I took the Angular jump
It seems to me that you just think "the latest thing" is amazing whatever that is, and the second something new comes out the thing you used to love is now garbage. A lot of your complaints aren't really webforms related, they stem from how you choose to use it, and things like gulp tasks to bundle, sass etc might make "new" tech seem better, but again that is unrelated to webforms, you can still use all of that tech on webforms projects.
As for your website, it look me about 10 seconds to put it into a broken state....
Loading....[^]
maybe it's not the tools you're using that is important, maybe it's how you use them? 
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F-ES Sitecore wrote: there wasn't as much of a learning curve.
Which seems like a good idea, until you see all of the developers who've never had to understand how it works "behind the scenes", who don't know which part of their code is running on the server, which part is running on the client, or even what the difference is between the two.
A problem that isn't helped by Visual Studio, where you develop and debug your server code in an interactive process on the same machine you use as the client.
Sometimes a learning curve is a good thing.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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I agree, but we now have the advantage of hindsight. Back then they obviously thought different, and have since changed direction as web dev is now so ubiquitous there is nothing wrong with making it a completely separate discipline.
As for "why does my code work on my local machine but not after I've deployed" brigade, we had that on classic ASP, web forms and it still exists in MVC, you can still write server code where the html goes, but I think the fact that people are conditioned against writing code in the view means we see less "Why does Word not show when I click button, it works on my local machine" questions.
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In the last years of me using WebForms, I did ditch the HTML objects for straight HTML and tried to normalize it as much as possible. I must admit that I have seen a few very good WebForm applications out there like Home - League Secretary. Not sure if the developer has made the switch to MVC yet.
I should of kept quiet on this subject and not said a thing about it. I might go back and delete my message. I can see all the WebForm proponents attacking my website, which is Ok for about a week so I can beef up the durability.
On my website crashing, I think I made a mistake in packing the that docker container and my controller API's were an older version that didn't match the client. The database basically just crashed and didn't bother to restart. I fixed it last night, and posted another build today. You have to refresh the browser to reload the new version.
The ViewState, could of swore I got that part right, or perhaps I read up on it with fake news. I can't remember my exact issue in detail about ViewState overall, but I can flash back to going through the Event Viewer and trying to fix every error with my WebForms E-Commerce site.
Advantages of server-side View State
The main advantage is that if a browser does not support a large encrypted file that is generated by the client-side View State then by the client-side View State we can handle it. As we know sometimes when we open an ASP web site in ASP.NET there will be some time corruption problem so it also minimizes the corruption problem. It also converts large client-side pages into a small client-side page because the View State data is stored at the server.
Disadvantages of Server-side View State
The main draw back is that the developer does not know how much space is taken by a View State on the server. If it takes a very large space there will be a problem. Another disadvantage is that server-side View State uses the server memory for the session object.
I sort of get frustrated with Asp.net post here and WebForm questions, like Richard said, most of the post don't know if their problem is on the client or server side. And all those GridView questions. I just got fed up with it and moved on to MVC.
If it ain't broke don't fix it
Discover my world at jkirkerx.com
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And with MVC people think everything has to be done with jQuery, that tables can only be created by jGrid (or whatever), they don't realise that Entity Framework is not a part of MVC and struggle with "using models without EF", they struggle getting their data from their view to their controllers because they don't understand model binding, they struggle using dropdown boxes because they don't understand the helper, they struggle with Url.Action because they don't understand the overloads, they're using json but don't understand the format or how to deserialise it, and so on.
I'm not saying webforms is perfect, or even good, I'm saying that all platforms have their quirks and issues and when you move from one to another you're simply moving from one set of common problems to another. Saying "this old tech is bad because of <these> problems" whilst completely ignoring all of the new problems that come with whatever is in fashion at the moment isn't giving a very fair or balanced view of the technologies in question. Criticise a tech all you want, as long as your criticisms are fair and accurate but don't give the impression that the tech de jour is going to solve all your problems and have no issues of its own.
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I agree 100%
Guess in hindsight, my gripe with WebForms was just related to me wanting to do more with UI and JavaScript and create more fluid interfaces. My target audience at the time was low skilled construction workers still running Windows XP and Corp buyers using the latest in tech. I wasn't able to make the UI easier to use in Checkout. Plus I designed a really bad data model for Checkout as well. The checkout process killed me.
I really feel that the concept of MVC has solved alot of the previous issues I had with WebForms. Whether the MVC is MVC, or Angular, Drupal, or something in PHP, I just like MVC better.
But to reiterate again, it's a shame that WebForms has sort of locked coders into a box, a certain way of thinking that seems to block new exploration into the parts that make up WebForms, to basically create HTML and use the HTTP protocol in general. Or to move forward to disassemble WebForms into it's actual components, and put it back together again as something better with other components.
If it ain't broke don't fix it
Discover my world at jkirkerx.com
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