how to read text file specifications row and column in c#

问题

i want read the each row and column but why it will pop out error message "make sure that the maximum index on a list is less than the list size".pls help...

string[] lines = File.ReadAllLines("C:\\test.txt");

        for (int i = 0; i < lines.Length; i++)
        {
            string[] line = lines[i].Split('^');
            for (int j = 0; j < line.Length; j++)
            {
                textBox1.Text = line[1];

                break;
            }
        }

回答1:

I think you wanted to have j in the line

textBox1.Text = line[j];

instead of

textBox1.Text = line[1];

Or it won't work if there's more than one part in the line split by ^.

Full code:

string[] lines = File.ReadAllLines("C:\\test.txt");

    for (int i = 0; i < lines.Length; i++)
    {
        string[] line = lines[i].Split('^');
        for (int j = 0; j < line.Length; j++)
        {
            textBox1.Text = line[j];

            break;
        }
    }

You may also consider changing the line textBox1.Text = line[j]; as it will overwrite the text in the loop.

EDIT

Based on the comment below, the code to read the first column from the first row is:

string[] lines = File.ReadAllLines("C:\\test.txt");
if (lines.Length > 0)
{
    string[] line = lines[0].Split('^');
    if (line.Length > 0)
        textBox1.Text = line[0];
}

回答2:

Maybe you have an empty line or a line without ^. Because your accessing the second item in the array of strings here:

textBox1.Text = line[1];

perhaps you want to access always the first element, then use 0 since indices are zero based:

textBox1.Text = line[0];

However, more meaningful would be

textBox1.Text += line[j];

Since you are looping the columns anyway.

but i just want read row 1 and col 1 ...so how ??

Then you don't need a loop at all:

string firstLinesColumnOne = lines.Length > 0 ? lines[0].Split('^')[0] : "";
textBox1.Text = firstLinesFirstColumn;

if i want read each column and display to different text box? example text file is row1 {ab cd ef} row2 {dc fc fd} row3 {dg hj ki} so output should be textbox1 = column 1 textbox2 = column 2 textbox3 = column 3

Assuming you want to assign split three columns to three textboxes and add a new line for every line in the file in the textbox as well:

IEnumerable<String[]> lineColumns = lines
    .Select(line => line.Split('^'));
textBox1.Lines = lineColumns.Select(cols => cols[0]).ToArray();
textBox2.Lines = lineColumns.Select(cols => cols[1]).ToArray();
textBox3.Lines = lineColumns.Select(cols => cols[2]).ToArray();

回答3:

        for (int j = 0; j < line.Length; j++)
        {
            textBox1.Text = line[1];

if line.Length == 1 there is no line[1], there is only line[0]

来源：https://stackoverflow.com/questions/19421745/how-to-read-text-file-specifications-row-and-column-in-c-sharp

标签

text-files