From Excel (or any file) to Array List C#

Question

I want to put some numbers from Excel to array. Let's say I have an Excel file with some numbers like this:

23 34 1 3 100 56 45 43 56 4 87 6 89 9

this is just one column in excel (or any file) And i want to put those numers in arraylist as integer numbers, i dont need the result as one number but all those numbers to be in int value.

Any help please ?

Answer 1

Assuming that the above is a string (and the source does not matter), you can do the following:

string s = "23 34 1 3 100 56 45 43 56 4 87 6 89 9";
string[] numbers = s.Split(' ');

ArrayList numberList = new ArrayList();
int i;

foreach (String num in numbers)
{
    if (Int32.TryParse(num, out i))
        numberList.Add(i);
    else
        Console.WriteLine("'{0}' is not a number!", num);
}

listBox1.DataSource = numberList;

I suggest using List<int> instead of ArrayList for type safety.

The following code reads all values from an Excel sheet into a data set using a DB connection. You can then pick the value needed.:

String sConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + filename + ";" + "Extended Properties=\"Excel 8.0;HDR=NO;IMEX=1ReadOnly=False\"";

OleDbConnection objConn = new OleDbConnection(sConnectionString);

objConn.Open();
OleDbCommand objCmdSelect = new OleDbCommand("SELECT * FROM [" + sheetname + "$]", objConn);

OleDbDataAdapter objAdapter1 = new OleDbDataAdapter();
objAdapter1.SelectCommand = objCmdSelect;

DataSet dsExcelContent = new DataSet();
objAdapter1.Fill(dsExcelContent);

objConn.Close();

EDIT
You did not specify the exact source for the string, so if this question is about how to read a file or how to import data from an Excel spreadsheet, you should probably rephrase your question a little.

EDIT 2
Replaced List<int> by ArrayList on OP's wish (against better design).

EDIT 3
Added a new line to show the OP how to use the ArrayList as a data source for a ListBox ...

EDIT 4
Added code to read Excel sheet using OleDB.

Answer 2

This is quite easy be splitting the string and parsing each item into a list.

String input = "23 34 1 3 100 56 45 43 56 4 87 6 89 9";

List<Int32> result = input
    .Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
    .Select(i => Int32.Parse(i))
    .ToList();

Note that this code has no error handling. If an item is not a valid integer, an exception will be thrown. You can handle this case by using Int32.TryParse() . You best do this without LINQ, but you can use the following inefficent LINQ code, too.

Int32 dummy;
List<Int32> result = input
    .Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
    .Where(i => Int32.TryParse(i, out dummy))
    .Select(i => Int32.Parse(i))
    .ToList();

Without LINQ.

String input = "23 34 1 3 100 56 h45 43 56 4 87 6 89 9";

Int32 dummy;
List<Int32> result = new List<Int32>();

foreach (String item in input.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries))
{
    Int32 number;
    if (Int32.TryParse(item, out number))
    {
        result.Add(number);
    }
    else
    {
        // Handle invalid items.
    }
}

Answer 3

您也可以导出为文件格式，即xml或csv，然后从c＃程序中对此进行解析。