Generating Unique Numbers - C# Discussion Boards

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Re: List

Guffa25-Jul-07 3:22

Guffa

25-Jul-07 3:22

foreach (SomeType theItem in someList) {
   DoSomethingWith(theItem);
}

---
single minded; short sighted; long gone;

Re: List

PhilDanger25-Jul-07 3:29

PhilDanger

25-Jul-07 3:29

----
List<int> intList = new List<int>();
//fill the list
//...

foreach(int myInt in intList){
Console.WriteLine(myInt);
}
----
This enumerates over all integers in intList, storing them in the variable myInt inside the loop so that you can access it.

Note that you can't edit the list itself during this loop, so if you are trying to remove an element from the list you will get an exception thrown. The way around this is to make a separate list to store the elements that you want removed, then loop through those later and remove them from your original list OR, see below (looping backwards and removing elements)

----
//loops through intList and removes every 0 from the list
cont int BADVAL = 0;
for(int i = intList.Count - 1; i >= 0; --i){
if(intList[i] == BADVAL){
intList.RemoveAt(i); //removes the current index from the list
}
}
----

Re: List

sangramkp25-Jul-07 4:50

sangramkp

25-Jul-07 4:50

Hi PhilDanger,

Thanks for reply...

I have a specific problem.... I hope u will help me out

SeatEntity is a class having fields seat_id and row_id and properties SeatId and RowId. I stored the SeatId and RowId in a List<seatentity> now while iterating each and every cell of a dataGridView Control I want to iterate through each item in List<eeatentity> and comapre its values with the cells RowIndex and ColumnIndex....
Ur help will be much aapreciated

Re: List

PhilDanger25-Jul-07 5:01

PhilDanger

25-Jul-07 5:01

In your loop that iterates through the DataGridView, assume that you have two values RowIndex and ColumnIndex that point to the appropriate cell.

//this is inside the loop of the datagrid view...
SeatEntity gridSeat = (SeatEntity)gridView[ColumnIndex, RowIndex].Value;
//We did a few things here, we indexed into the gridView using the column and the row, this returns a DataGridViewCell.
//We then used the .Value property to get what is stored inside.  Since this returns an object, we cast it to the type that we stored in the grid (I'm assuming you're storing SeatEntitys).

//now we can loop through the list and compare the values
foreach(SeatEntity seat in seatList){
    if(seat.SeatId == gridSeat.SeatId){
         //do something
    }
}

Re: List

sangramkp25-Jul-07 6:32

sangramkp

25-Jul-07 6:32

Hi I am sending u the code if u can help better

SeatChartService scs = new SeatChartService();

private void Form1_Load(object sender, EventArgs e)
{
List<seatentitiy> seat = scs.GetSeats();

//dataGridView1.DataSource = seat;
dataGridView1.ColumnCount = scs.GetColumnCount();
dataGridView1.RowCount = scs.GetRowCount();
int i = 0;
int j = 0;

foreach (DataGridViewTextBoxColumn c in dataGridView1.Columns)
{
c.HeaderText = i.ToString();
i++;
}

foreach (DataGridViewRow r in dataGridView1.Rows)
{
r.HeaderCell.Value = j.ToString();
j++;
}

SeatEntitiy seobj= new SeatEntitiy();
foreach (DataGridViewRow row in dataGridView1.Rows)
{
foreach (DataGridViewCell cell in row.Cells)
{
foreach (SeatEntitiy se in seat)
{
//SeatEntity gridSeat = (SeatEntity)cell[ColumnIndex, RowIndex].Value;

seobj.SeatId = se.SeatId.ToString();
seobj.RowId = se.RowId.ToString();
if (cell.ColumnIndex.ToString() == seobj.SeatId.Substring(14) && cell.RowIndex.ToString() == seobj.RowId.Substring(12))
{
cell.Style.BackColor = Color.Green;
//MessageBox.Show(cell.ColumnIndex.ToString(),cell.RowIndex.ToString());
}
else
{
cell.Style.BackColor = Color.Red;
}
}
}
}

}

Re: List

PhilDanger25-Jul-07 6:50

PhilDanger

25-Jul-07 6:50

What's the problem with this code?

Re: help needed using gprs connection

Justin Perez25-Jul-07 3:06

Justin Perez

25-Jul-07 3:06

Wrong forum, see Mobile Development[^]

I get all the news I need from the weather report - Paul Simon (from "The Only Living Boy in New York")

Generating Unique Numbers

Jalpesh B. Patel25-Jul-07 2:55

Jalpesh B. Patel

25-Jul-07 2:55

Hi,

I would like to make an application that generates unique numbers (numerics only) in sequential order (better if this way but not compulsory).

It should be able to recover in case of a crash. i.e. if the generation crashes or system crashes, then the next time its up, it should give unique numbers only, and not repeat any number previously given. This is of utmost importance.

And if crash recovery feature doesn't involve I/O, it would be better. (e.g saving numbers to disk and stuff).

Note: Random is not mandatory, unique is.

If you have a solution to this, please help.

Thank you.