List in popup window

Question

I have a program that uses a List of objects.

I want to show the content of the List in a popup-window.

How can I do this in a simple way.

I know I´ve done the same in Java, where I think I simply created a new frame. Can I also create a new form?

Vulpes · Answer

Yes, a ListView might be more suitable. However, you could still use a ListBox by creating another list which combines those two properties and then bind to that. Although you're using List for some reason, I assume that the list actually contains Customer objects. If that's the case, the code would be something like this: public Form2(List CustomerList) { List items = new List (); foreach(object obj in CustomerList) { Customer c = obj as Customer; if (c == null) continue; string item = c.personNr + " " + c.Name; items.Add(item); } listBox1.DataSource = items; // no need to set DisplayMember or ValueMember properties }

Sam Hobbs · Answer

I think Vulpes was a little hasty in creating sample code. To get the sample code to work, you will need to create the "items" array as a member of the form. The important thing is that you can use the DataSource property of the control. The following sample works. public partial class Form1 : Form { List Objects > items = new List Objects >(3); public Form1() { InitializeComponent(); listBox1.DataSource = items; items.Add( new Objects ()); items[0].id = "9" ; items[0].name = "Peter" ; items.Add( new Objects ()); items[1].id = "1" ; items[1].name = "Paul" ; items.Add( new Objects ()); items[2].id = "6" ; items[2].name = "Mary" ; listBox1.DisplayMember = "name" ; listBox1.ValueMember = "id" ; } } class Objects { public string id { get ; set ; } public string name { get ; set ;} }

Sam Hobbs · Answer

Yes it is very much a matter of judgement. I don't expect perfection but I do wish others would make as much of an effort as you do and that are as understanding as you.

Lars Persson · Answer

Well I see your point and I´m glad you see mine. But I'll try to keep one subject a thread I think. Often when I search (here and other forums) it´s very hard to find a correct answer, even if someone already answered your question. I suppose it´s a matter of judgment.

Sam Hobbs · Answer

Your thinking is correct. It does help to keep related subjects together. So perhaps I am being too picky again.

Lars Persson · Answer

Well, again I´m sorry. I suppose I felt that since it is the same program I´m working on it would make sense to keep it in one thread. That way don´t have to explain the background every time. But it does make it harder to search, that true. I am now trying to keep once subject a thread.

Sam Hobbs · Answer

The rules in most forums is for one question per thread. There are many reasons for that. It helps to keep threads from getting very long. It helps others looking for help so they do not have to read through many irrelevant replies. It helps others to find answers if the subject indicates what is in the thread. It helps you to get answers when the subject is relevant to the question.

Lars Persson · Answer

Thanks Vulpes, a very clear explanation!

Vulpes · Answer

Although you can add any type of object or value to a List , if you're only going to add a single type of object, then it's far preferable to create a List of that type. If you think about it, it makes no sense for a public method to take parameters which are less accessible. Here, Form2's constructor is public so you need List to be public and (since List is public anyway) you also need CSharpProjekt.Kund to be public as well. The default accessibility for any class (or other type) is internal i.e. it can only be accessed from code within the same assembly. So making it public solves the problem. As far as OO design is concerned, you should only make a class as accessible as it needs to be. Since it needs to be public here, then that's fine.

Lars Persson · Answer

The error-message I get is: Error 1 Inconsistent accessibility: parameter type 'System.Collections.Generic.List ' is less accessible than method 'CSharpProjekt.Form2.Form2(System.Collections.Generic.List )' I googled the error and one suggestion was to make the class public. This worked but is it god OOP-design? Why is a class default private?

Sam Hobbs · Answer

I will need more information. What is not accessible? My guess is that the error is for members of the Customer class and if so then probably you simply need to make them public.

Lars Persson · Answer

Well, I did put List CustomerList because I was thinking that you could put any kind of object in the list. Maybe not a good idea. Also not a good idea to use a listBox. Your suggestions are fine but I remembered that I used richTextBox which worked fine. But now I have another question: When I use the generic List CustomerList it is no problem to send it to the constructor of Form2. But when I use List Customerlist (if customer is a class) it doesn't work. The complaint is about accessibility. But how do I solve it?

Sam Hobbs · Answer

Actually the name "Objects" was my choice and as I said it was a bad choice. It is the plural version of Object so it is not the class that all .Net classes derive from. ListView might not work well; it is relatively inflexible. A DataGridView would be a good choice.

Sam Hobbs · Answer

Note that a listbox is for showing a list of items in which there is one string and only one string for each item. If you want more than one item, such as a book ISBN, title and author then you need to use a different control. In the sample code I provided, "ValueMember" is for a member of a class that is for use in your program; the form does not show the ValueMember item. The form shows the "DisplayMember" item but when an item in the list is selected, your program can get the ValueMember value corresponding to what was selected. In my sample code, I have a class called Objects. I create a list ("List ") of instances of the class. Then I add objects (instances of the "Objects" class) to the list and the items automatically appear in the listbox. Note that I am using the name "Objects" for the class and that can be confusing. I should not have done that but I was not sure what name to use. Your question is vague. You say " List of objects ". If the the sample code does not do what you need done then it would have helped for the question to have been more specific.

Lars Persson · Answer

I´m confused: In Form1 I have : private void btnSkrivUtKundLista_Click( object sender, EventArgs e) { Form2 f2 = new Form2 (CustomerList); f2.ShowDialog(); } And then in Form2: public Form2( List Object > CustomerList) { listBox1.DataSource = CustomerList; listBox1.ValueMember = " personNr " ; listBox1.DisplayMember = "Name" ; } Now I can show "personNr" or Name but not both at the same time. Also i can´t see any choise to appendText as in my other listBox. How can I show both the values? }

Lars Persson · Answer

Well, I think credit where credit´s due. Both of your answers where good and you should both have credit for that. I am also active in other forums and so many times instead of answer the question they reply in a bad way. Maybe pointing out how stupid you are for asking such a question or the usual "Google it!". I have two things to say about "Google it!": 1. You probably have Google it but found it hard to find the correct answer. Either there isn't one or there are too many. 2. You go to a forum because you expect that the people there are some kind of experts. They can quicker give you the correct answer or point you in the right direction. If people say "Google it!" it is only a waste of my and their time. I know I can Google it! Here as of yet I have found that the answers are good and given in a polite manor. That should be rewarded!

Sam Hobbs · Answer

I was being too critical. The rules are that you decide what reply, if any, is the answer. We appreciate that you do take the time to choose one reply as an answer. I should do nothing to discourage that. I have been active in forums in another web site wherein replies are seldonm recognized as having any value.

Lars Persson · Answer

Well. As I said I have still to learn how it works here. Didn´t think it would matter. I only marked one answer as correct to mark the thread as solved I think. Of course you should have points to! Fixed that now. (I hope).

Sam Hobbs · Answer

So why does Vulpes get marked as the answer? I sure do not understand that. I don't need the points but it is sure something I am very curious about. It sure is quite bizarre to me.

Lars Persson · Answer

Great! Thank you both!

Vulpes · Answer

Just add a new Form class to your project, Form2 say, and add a ListBox or ListView control to it. Change it's constructor to read as follows: public Form2(string[] items) { InitializeComponent(); listBox1.DataSource = items; listBox1.SelectedIndex = 0; } Now, on the main form, add a button - button1 say, and place the following code in its Click eventhandler: private void button1_Click(object sender, EventArgs e) { string[] items = { "Peter", "Paul", "Mary" }; Form2 f2 = new Form2(items); f2.ShowDialog(); } Instead of a string array, you can of course pass an array of your own objects. However, you'll need to specify the property to be displayed in the listbox. For example: listBox1.DisplayMember = "Name";

Lars Persson · Answer

I´m sorry, I have yet to learn the forum rules It is a windows-form and I didn´t realise that there was a separate forum for that. Anyway, thanks for the replies but as stated it is a window-form popup I need.

Sam Hobbs · Answer

What UI? Windows Forms, WPF/Soilverlight or ASP.Net? It helps to post UI questions in the appropriate forum so we do not need to get clarification but you alternativley could at least specify in the question what the UI is. This forum is for questions about the C# language but not about UI using C#. Edit: Senthilkumar and I obviously created our replies in parallel. If the question is about an ASP.Net application then hopefully it is answered. Otherwise we still need clarificaiton.

Senthilkumar · Answer

Hi, There are number of ways to show the popup. 1) You can use the div tag and set the z-index. The style you can define and initially it will be in hidden state and when you want to show then you make it visible. http://raventools.com/blog/create-a-modal-dialog-using-css-and-javascript/ 2) You can use the iframe and set the z-index, background transparent. 3) You can use the window modal dialog (only supports in IE) showModalDialog method example function showModalWindow() { window.showModalDialog("ModalPage.html", "Sample.jpg","resizable: yes"); } align="center"> showModalDialog() Example Click on the image to view full image http://www.roseindia.net/javascript/javascript-showmodaldialog.shtml 3) You can use the AJAX toolkit modal popup http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/ModalPopup/ModalPopup.aspx O ther than that you can use the external javascripts like extJs, jQuery, etc.., http://www.designlabelblog.com/2009/03/20-ways-to-create-javascript-modal.html

List in popup window

Answers (24)