ExcelColumnCollection Class

public sealed class ExcelColumnCollection : ExcelRowColumnCollectionBase<ExcelColumn>

Public NotInheritable Class ExcelColumnCollection
	Inherits ExcelRowColumnCollectionBase(Of ExcelColumn)

foreach (ExcelColumn column in ws.Columns)
{
    // Writes hidden columns
    if (column.Hidden)
        Console.WriteLine("Column '{0}' is hidden", ExcelColumnCollection.ColumnIndexToName(column.Index));
}

// Counts used columns (columns that contain some data)
Console.WriteLine("Number of used columns is: {0}", ws.CalculateMaxUsedColumns());

For Each column In ws.Columns
    ' Writes hidden columns
    If column.Hidden Then
        Console.WriteLine("Column '{0}' is hidden", ExcelColumnCollection.ColumnIndexToName(column.Index))
    End If
Next

' Counts used columns (columns that contain some data)
Console.WriteLine("Number of used columns is: {0}", ws.CalculateMaxUsedColumns())