problem with load data to listview

Question

1.00/5 (1 vote)

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Hi i want to load data to my listView and when i do it it has no problem with items but for subitems it add just the last word from the text file
can someone tell me what should i do?
My Problem Picture[^]
and here is my code

C#

private void LoadData(ListView slv)
{
    string[] lines2 = File.ReadAllLines("b.bat");
    foreach (string line2 in lines2)
    {
        b = line2 + "\n";
    }
    string[] lines = File.ReadAllLines("a.bat");
    foreach (string line in lines)
    {
        a = line + "\n";
        ListViewItem item = new ListViewItem(a);
        item.SubItems.Add(b);
        slv.Items.AddRange(new ListViewItem[] { item });
    }
}

i doing without problem for items but for subItems it just add the last one
With Respect

Posted 1-Dec-14 5:15am

Avenger1

Updated 2-Dec-14 2:52am

v3

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Comments

BillWoodruff 1-Dec-14 19:28pm

RyanDev has shown you the problem in your code.

I'd like to suggest that for questions like this you just post the code in your question: the code is not "huge," and it's distracting to have to open a web-page to go study a picture to figure out what's going on, in fact I predict many people here will just skip considering your question because of the link to an external source.

Avenger1 2-Dec-14 8:53am

i fixed my question
i didn't understand what to do in that solution
please help me to fix it
With Respect

BillWoodruff 2-Dec-14 21:39pm

Wasn't this question already asked and answered in another thread ?

syed shanu 2-Dec-14 21:38pm

HI,
Do you want to display both b.bat and a.bat file lines to display in 2 separate column of list view for example first column display b.bat file line and 2nd column of listview display a.bat of line.
If you tell more clearly your requirement it will be easy to tell the solution.

3 solutions

Solution 1

If you debugged it you would see exactly what is happening. You're first loop runs which all it does is assign a value to b. It then does another loop using the value which is now in b which is of course the last value.

It looks like you'll want to do a nested loop but without knowing for sure what you want, it's hard to say for sure.

Posted 1-Dec-14 5:28am

ZurdoDev

Comments

Avenger1 1-Dec-14 11:35am

i did it and it was normal but as you see it add just the last subItem
please help me to fix it
With Respect

ZurdoDev 1-Dec-14 11:53am

Of course it only adds the last subitem. Where exactly are you stuck then? I already explained how to fix it.

BillWoodruff 1-Dec-14 19:28pm

+5

Solution 3

C#

private void LoadData(ListView slv)
{
    string[] subItems = File.ReadAllLines("b.bat");

    string[] items = File.ReadAllLines("a.bat");

    foreach (string item in items)
    {
        ListViewItem lvItem = new ListViewItem(item);

        foreach (string subItem in subItems)
        {
            lvItem.SubItems.Add(new ListViewItem.ListViewSubItem(lvItem,subItem));
        }

        slv.Items.Add(lvItem);
    }
}

Just keep in mind that that you must add the ListViewItem.ListViewSubItem(s) inside the loop where you build/add the ListViewItem(s).

Posted 2-Dec-14 15:58pm

BillWoodruff

Comments

Avenger1 2-Dec-14 23:45pm

thanks bill but your answer just add first subitem and the second Solution was the great answer
With Respect

BillWoodruff 3-Dec-14 0:14am

Hey, I'm glad you got a userful answer; my interpretation of what you were after was something that given:

private string[] items = new string[4] {"1", "2", "3", "4"};
private string[] subItems = new string[4] {"a", "b", "c", "d"};

produced:

1 a b c d
2 a b c d
3 a b c d
4 a b c d

:)

If you are simply getting one SubItem per row of output, you do not need a loop inside a loop !

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DamithSL · Accepted Answer · 2014-12-02T03:36:00

Solution 2

you need loop inside loop or use LINQ to build the data you need from two files. for example :

C#

string[] lines2  = File.ReadAllLines("b.bat");
string[] lines  = File.ReadAllLines("a.bat");
if(lines2.Length == lines.Length)
{
    var res = lines2.Zip(lines, ( a,b) => new string[] { a, b});
    slv.Items.AddRange(res.Select(r=> new ListViewItem(r)).ToArray());
}

OR

C#

listView1.Items.AddRange(lines2.Zip(lines, (a, b) => new ListViewItem( new [] { a, b })).ToArray());

Posted 2-Dec-14 3:36am

DamithSL

Updated 2-Dec-14 16:13pm

v3

Comments

Avenger1 2-Dec-14 17:35pm

this code showed but for example if i had two items and two subitems it showed me 4 items and 4 subitems
what should i do?
With Respect

DamithSL 2-Dec-14 20:20pm

check my updated answer

BillWoodruff 2-Dec-14 21:38pm

That's very interesting code; I am trying to understand how that handles both adding ListViewItems and SubItems. thanks, Bill

DamithSL 2-Dec-14 22:19pm

Is it? loop will do the same but again it will be doing the homework as suggested in 1st answer. that's why I have post LINQ solution with combining two arrays and generate the array of list items. Hope this will help someone else in future :) (at least check what is Enumerable.Zip method)

BillWoodruff 2-Dec-14 22:59pm

using your code with this test data:

private string[] items = new string[4] {"1", "2", "3", "4"};
private string[] subItems = new string[4] {"a", "b", "c", "d"};

the ListView shows only values in the first (Item) and second (SubItem) columns: no SubItems shown in 3rd. to 5th. columns.

DamithSL 2-Dec-14 23:04pm

it will display as below
col1 col2
1 a
2 b
3 c

BillWoodruff 3-Dec-14 0:14am

It's clear to me we have a different interpretation of what the OP is asking. But, I'm happy he got a good answer from you !

If the code is only using one SubItem from a List per row of output, there is no need for a loop within a loop.

Avenger1 2-Dec-14 23:42pm

thanks a lot, this code did the best
;)
just can you tel me about the code, please?
i m not understanding how it works
With Respect

DamithSL 2-Dec-14 23:53pm

cool,
1. you can create listview item by giving array of items new ListViewItem(stringArray)
2. but for that you need to create new array from two arrays you already have.
3. read Enumerable.Zip[^] it will help you to create the new array
4. finally add all the ListViewItems by using AddRange method