Re: c# listview insert not working - C# Discussion Boards

Richard MacCutchan9-Dec-13 5:37

9-Dec-13 5:37

I just tried that and it worked fine, is there something else that you are doing?

Veni, vidi, abiit domum

dbushong9-Dec-13 5:51

9-Dec-13 5:51

Thank you for replying.
The app has 2 listviews. The lvBOM listview has 7 cols.
I have supplied test data to all 70 rows in the first col only.
Here is the code for that:

for (int i = 0; i < intRCount; i++)
{
ListViewItem myItem = lvBOM.Items[i];//row
myItem.SubItems[1].Text = "5";//col

}
In the same button_click I followed that code with this code:

ListViewItem item = lvBOM.Items[2];//row

lvBOM.Items.Insert(2,"Hi");

The result is that the row is inserted but the data does not show. This data is test and only used to test the insert function.

Richard MacCutchan9-Dec-13 6:13

9-Dec-13 6:13

I have four rows and three columns in my control. When I press the button it runs the following code:

ListViewItem item = listView1.Items[2];//row
listView1.Items.Insert(2, "Hi");

The row is added, and the word "Hi" appears in column 1. I can only assume that there is something in your code that you have not shown us, which is causing a problem.

Veni, vidi, abiit domum

dbushong9-Dec-13 7:18

9-Dec-13 7:18

Thank you for hanging in there with me..

I just started a new project. In the form load I have the following.
I still cannot get it to work.

private void Form1_Load(object sender, EventArgs e)
{
lvBOM.Clear();
lvBOM.Width = 451;

lvBOM.Columns.Add("", 0, HorizontalAlignment.Center);//skip first col
lvBOM.Columns.Add("Level", 40, HorizontalAlignment.Center); //level 1 is base
lvBOM.Columns.Add("Part Number", 100, HorizontalAlignment.Center);
lvBOM.Columns.Add("Description", 250, HorizontalAlignment.Center);
lvBOM.Columns.Add("Qty", 40, HorizontalAlignment.Center);
lvBOM.Columns.Add("", 0, HorizontalAlignment.Center);//InventoryMstrGUID
lvBOM.Columns.Add("", 0, HorizontalAlignment.Center); //InventoryMstrGUIDMAIN

lvBOM.FullRowSelect = true;
lvBOM.View = View.Details;
for (int i = 1; i <= 70; i++)//'initialize rows so grid looks like a grid
{
var lvi = new ListViewItem("");//will add to column(0) not being used
lvi.SubItems.Add("");
lvi.SubItems.Add("");
lvi.SubItems.Add("");
lvi.SubItems.Add("");
lvi.SubItems.Add("");
lvi.SubItems.Add("");
lvBOM.Items.Add(lvi);
}
ListViewItem item = lvBOM.Items[2];//row

lvBOM.Items.Insert(2, "Hi");
}

Richard MacCutchan9-Dec-13 7:34

9-Dec-13 7:34

When you add the new item the text is placed in the first column. But you have chosen to hide that column, so the text never shows. Change the width of that column to something larger than 0 and it will work.

Veni, vidi, abiit domum

dbushong9-Dec-13 7:43

9-Dec-13 7:43

Thank you so much. But I apparently am having a fundamental problem.

ListViewItem item = lvBOM.Items[2];//<<<< this line inserts the row

lvBOM.Items.Insert(2, "Hi");//<<< I thought this line would select the 3rd col since the index is 2.

Column 0 is hidden = 0 index
column 1 is visible = 1 index
column 2 is visible = 2 index

I thought the "HI" would go into the 3rd column which has an index of 2.

What am I missing? How do I do this?

Richard MacCutchan9-Dec-13 7:47

9-Dec-13 7:47

No, you are adding an Item into the second position of the view. You need to set the string into the second subitem position of the item that you add.

Veni, vidi, abiit domum

dbushong9-Dec-13 8:03

9-Dec-13 8:03

I am rather new at listviews so please excuse my ignorance.
I searched for hours on the net before signing up for this forum.

I do not understand why this >> lvBOM.Items.Insert(2, "Hi"); won't work.

What is the '2' if not to place data in the 3rd col?

Can you give sample code?

dbushong9-Dec-13 8:41

9-Dec-13 8:41

I finally got it. Thank you very much.

Richard MacCutchan9-Dec-13 8:59

9-Dec-13 8:59

dbushong wrote:
I am rather new

Nothing wrong with that, we all had to learn at one time. Make good use of the reference pages on MSDN, like the ListView pages[^].

Veni, vidi, abiit domum

C# XML or Database

Member 104453489-Dec-13 2:57

9-Dec-13 2:57

I'm looking at trying to make a app. that keeps track of camp-sites for a season. I was wondering if I should go with a full blown database (which I assume cost money) or maybe go with a XML file.

If I went XML I was wondering what would be the best way to do it. All the information in one xml file. Or maybe one xml for each month of the season and keep track that way.

Any input would be great, thanks for taking the time to help a noobie out.

Stevish

Richard MacCutchan9-Dec-13 3:34

9-Dec-13 3:34

Microsoft offers SQL Server Express[^] or SQL Compact Edition[^], both free. It does depend somewhat on your total requirements.

Veni, vidi, abiit domum

Member 104453489-Dec-13 9:22

9-Dec-13 9:22

Not much for requirements, it's just a simple booking system I guess. I really new to C# are programming as a whole, did some PHP a while back. I just wanted to make something that could be useful while I am learning.

Thanks for the info!

Stephen

thatraja9-Dec-13 3:54

thatraja

9-Dec-13 3:54

Addition to Richard's suggestions, you could choose one more instead of XML. Sqlite[^]

Don't go with XML. There're many advantages(Editor-GUI, Security, Performance, etc.,) if you go with Database.

Just FYI(XML vs Databases), check these
XML vs. SQL database: which is the right one for you?[^]
When to use XML Instead of a Relational Database[^]

thatraja

Code converters | Education Needed
No thanks, I am all stocked up. - Luc Pattyn
When you're wrestling a gorilla, you don't stop when you're tired, you stop when the gorilla is - Henry Minute

Nicholas Marty9-Dec-13 4:15

Nicholas Marty

9-Dec-13 4:15

I also used XML for storing some data in some cases.

An advantage: You can manually tell the application which file you want to load (or store to) and keep multiple different versions at the same time without causing any problems. If you're using a database this is getting a bit more difficult. Also if you want to store them in a e.g a Source Control as most Databases store the data in some binary format. You can however easily compare different XML files with each other.

Besides. Database might generally offer better performance but they can also require quite a lot of resources to run. If you don't have lots of data an XML file might still be faster than a database.

Member 104453489-Dec-13 9:22

9-Dec-13 9:22

Thanks for your suggestion, I will read up on Sqlite

Thanks again!
Stephen

harold aptroot9-Dec-13 6:30

harold aptroot

9-Dec-13 6:30

The data doesn't sound particularly tree-like (could have been an excuse to use XML)
It sounds like a bunch of records - like a database. If you find that too heavy-weight, you could use a simple comma-separated text file, or maybe just serialize your array of records to a binary file.

Member 104453489-Dec-13 9:24

9-Dec-13 9:24

Ya your got me, I was looking for an excuse to fool around with XML.
I'll will likely go with one of the DB options above and start learning
about that.

Thanks again all for the great info! very helpful site

Stephen

Dave Kreskowiak9-Dec-13 10:10

Dave Kreskowiak

9-Dec-13 10:10

You're kid of comparing apples to oranges. XML is not a database. You can use it for simple tables and such but it has no query engine. Go with a true database engine and you'll be much better off.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Member 1044534810-Dec-13 1:41

10-Dec-13 1:41

Ya working on setting one of those free ones up now. If I went with the XML root I would of used linq to xml.

Again thanks all for the help!

Steve

Dave Kreskowiak10-Dec-13 2:36

Dave Kreskowiak

10-Dec-13 2:36

Member 10445348 wrote:
If I went with the XML root I would of used linq to xml.

That's not exactly what I would call "performant". There is no indexing with XML or LinqToXML. Searches only work by iterating over the entire set of rows in a field.

No thanks. I'll stick with a database engine.

On top of that, XML doesn't scale with the number of users. Add more than a small handful of users using the system simultaneously and you'll be begging for a database engine.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Member 1044534810-Dec-13 4:10

10-Dec-13 4:10

Your more then like right and that is the direction that I went. I'll likely be back for help from time to time lol. I guess I should fill out the member stuff so I don't have such a funny member name.

Again thanks for all your comments!

Cheers!

BobJanova10-Dec-13 4:32

BobJanova

10-Dec-13 4:32

XML is never the right answer to any data storage question unless that data is intrinsically tree based. XML is a text format, so you have issues with performance and accuracy saving numbers, dates and other binary formats, and it's a very verbose text format at that.

If you want tables of data with connections between them then you want a database or something that acts like one, otherwise you'll end up writing a query engine yourself and that's silly. As well as the free options already mentioned, mySQL is free, and if you don't want an external dependency, you can create an in memory DataSet (System.Data) which can be enough for simple applications.

If you don't think that a database is necessary for the level of complexity of your app, then it can make sense to use tab separated text files for each 'table'.

Member 1044534810-Dec-13 8:28