load words from text file to listbox

darma teja

Hi,

I loaded the data from database to listbox in my form. (every time it retrieves different number from the database)

now my listbox contains items as follows: (1st time:)

1021
1022
1023

later my listbox contains like this:

1021
1023

I have a text file like this: (I have almost 1000 rows here i am giving you only 3 rows)

1021 darma

1022 teja

1023 vulpes

Now i want to change my listbox numbers as follows:

1st time listbox should show like this:
darma
teja
vulpes

2nd time listbox should show like this:

darma
vulpes

Give me ideas to do.

Thanks allot

Darma

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
Accepted answer
It sounds like the numbers in the file are not unique as I was expecting them to be though I assume that a given number will always be associated with the same name.

Here's a modification to the previous code to deal with that:

string[] lines = System.IO.File.ReadAllLines("darma.txt");
string[] names = new string[lines.Length];
Dictionary dict = new Dictionary();

for (int i = 0; i < lines.Length; i++)
{
string[] items = lines[i].Split(' ');
if (!dict.ContainsKey(items[0]))
{
dict.Add(items[0], items[1]);
}
}

for (int i = 0; i < listBox1.Items.Count; i++)
{
names[i] = dict[listBox1.Items[i].ToString()];
}

listBox1.DataSource = names;
darma teja14y ago
Hi Vulpes,

You are genius man.

Darma
darma teja14y ago
Hi Vulpes,

Thanks allot once again.

I am getting exception at the line: dict.Add(items[0], items[1]);

The exception is like this: "An item with the same key has already been added"

Darma
Vulpes14y ago
I'm not 100% clear but it sounds like you need a Dictionary to associate the numbers with the corresponding names.

May be like this:

string[] lines = System.IO.File.ReadAllLines("darma.txt");
string[] names = new string[lines.Length];
Dictionary dict = new Dictionary();

for (int i = 0; i < lines.Length; i++)
{
string[] items = lines[i].Split(' ');
dict.Add(items[0], items[1]);
}

for (int i = 0; i < listBox1.Items.Count; i++)
{
names[i] = dict[listBox1.Items[i].ToString()];
}

listBox1.DataSource = names;
darma teja14y ago
Hi Vulpes,

Thanks allot for your reply.

Your code is to get all the names in listbox.

Actually i should not get all the names in my listbox.

These list box items are retrieved from other list box selected index changed event.

Now my list box get different numbers in different times based on other list box selected index changed event.

Based on the listbox numbers, i will change in names automatically.

Darma
Vulpes14y ago
The code to do that will be something like this:

string[] lines = System.IO.File.ReadAllLines("darma.txt");
string[] names = new string[lines.Length];
for(int i = 0; i < lines.Length; i++)
{
string[] items = lines[i].Split(' ');
lines[i] = items[1];
}
listBox1.DataSource = names;

This assumes there are no blank lines in the file.