How would I export a DataTable to a text file and define the string length and the start position of each column ?

My issue is I need to build a text file with a specific format. Each row (line) in the text file can only be 111 characters long and each row (line) in the text file will represent a single row from the DataTable.

DataTable:
Column1 | Column2 | Column3 | Column4
My |Phone # |is |8000000000
My |Phone # |is |9990000000

TextFile:

Column1 starts at position 0, Column2 starts at position 2, Column3 starts at position 40, Column4 starts at position 90,

MyPhone# is 8000000000
MyPhone# is 9990000000

I am able to use

public void ExportDataTabletoFile(DataTable datatable, string delimited, bool exportcolumnsheader, string file)

{
    StreamWriter str = new StreamWriter(file, false, System.Text.Encoding.Default);
    if (exportcolumnsheader)
    {
        string Columns = string.Empty;
        foreach (DataColumn column in datatable.Columns)
        {
            Columns += column.ColumnName + delimited;
        }
        str.WriteLine(Columns.Remove(Columns.Length - 1, 1));
    }
    foreach (DataRow datarow in datatable.Rows)
    {
        string row = string.Empty;
 
        foreach (object items in datarow.ItemArray)
        {
 
            row += items.ToString() + delimited;
        }
        str.WriteLine(row.Remove(row.Length - 1, 1));
 
    }
    str.Flush();
    str.Close();
 
}

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And call it like

ExportDataTabletoFile(GetTable(), " ,", false, file);

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but that is all I can come up with.

result:

My,Phone#,is,8000000000
My,Phone#,is,9990000000

Can any one expand on this for me.

Thanks.....

// Get each row of the DataTable foreach (DataRow datarow in datatable.Rows) { // Holds the formatted string of the row string row = string.Empty; // Holds the column values of the row object[] col = datarow.ItemArray; // Format the line of the file with the correct field width row = String.Format("{0,2}{1,-37}{2,-50}{3,-10}", col ); // Write the formatted line to the file str.WriteLine(row.Remove(row.Length - 1, 1)); } str.Flush(); str.Close();

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LVL 65

Fernando SotoRetiredCommented: 2015-06-25

Hi GD_GRAY;

The below code snippet is part of your code modify to write a formatted line. The format specifier such as {1,-37}, will format the second item in the array with index 1 to always have 37 character position and left justified, - means left justified. Now your sample output did not have a delimiter and seeming each column is a fixed width you do not need a delimiter. You can also apply this same idea with the header names.

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LVL 90

David Johnson, CD, MVPOwnerCommented: 2015-06-25

you will have to build your strings by yourself
Do you want
my,phone, is, ######## or
column1start = 0
column2start=4
column3start=40
column4start-90
output = column1.text + ","
spaces = column2start - strlen(output)
spacer = ""
for (I=0;i<spaces;i++){spacer += " ";}
output= output + spacer + column2.txt + ",";
spaces = column3start - strlen(output);
spacer = ""
for (I=0;i<spaces;i++){spacer += " ";}
output= output + spacer + column3.txt + ",";
spaces = column4start - strlen(output);
spacer = ""
for (I=0;i<spaces;i++){spacer += " ";}
output= output + spacer + column4.txt;
write(output);

GD_GRAYAuthor Commented: 2015-06-25

Wow......

Thank you !

Soto Sir,

Any way to get the string format values from a list, or a datatable column ?

Fernando SotoRetiredCommented: 2015-06-26

To your followup question, "Any way to get the string format values from a list, or a datatable column ?", the format specifier is just a string and can be stored in a list or any object that can store a string in. When you are ready to use it retrieve it from where you are storing it and place it in a string variable and use that string variable where the specifier is now.

How would I export a DataTable to a text file and define the string length and the start position of each column ?

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