c# 4.0 - Maximum value in datatable column c# -

i have set of text files reading datatable. want able read frist column (id) , find out highest number. each of files goes 0 @ least 21 sequentially. tried suggestions following link: how select min , max values of column in datatable?

sadly, not work. 1 suggestion kind of worked shown in second last line, returns value of 8 or 9. suggestions how results looking for?

        string filepath = system.io.path.getfullpath(curriculum);         datatable curriculmdatatable = new datatable();          curriculmdatatable.columns.add("id");         curriculmdatatable.columns.add("course");         curriculmdatatable.columns.add("credit");          // read in file line-by-line, , store         var txtfileline = file.readalllines(filepath).tolist();          //reads line splits data colums @ tab (ascii value 9)         txtfileline.foreach(line => curriculmdatatable.rows.add(line.split((char)9)));           //suggestions link         int max = convert.toint32(curriculmdatatable.select("id=max(id)")[0][0]);            label1.text = ""+ max; 

the problem have created string columns want max-values according numeric value. best way store corrrect type in first place. either use datatable.compute or linq-to-dataset:

create int column:

 curriculmdatatable.columns.add("id", typeof(int)); 

convert strings int , add them table:

foreach(string line in file.readlines(filepath)) {     datarow row = curriculmdatatable.rows.add();     string[] fields = line.split(new[]{(char)9});     int id;     if(fields.length == 3 && int.tryparse(fields[0], out id)     {         row.setfield("id", id);         row.setfield("course", fields[1]);         row.setfield("credit", fields[2]);     } } 

now can use linq:

int maxid = curriculmdatatable.asenumerable().max(r => r.field<int>("id")); 

datatable.compute (works earlier .net versions):

int maxid = (int)curriculmdatatable.compute("max(id)", "")