foreach Loop in C#

foreach (DataRow rowSec in ud.m_UsertestGroupsTable.Rows)
    {
        
             if( (bool)rowSec["ColumnName"] == true)
             // or if((bool)rowSec[columnIndex] == true)
             {
                 //do something. 
             }

        I suggest you Please not use index, prefer to Column Name

foreach(DataRow drow in dt.Rows)
 {
      string value = drow[columnname].ToString();
 }