Check the below code.
C#
DataTable dt = new DataTable();
dt.Columns.Add("Name");
dt.Rows.Add("John Hammond");
dt.Rows.Add("Mudasssar Khan");
dt.Rows.Add("Suzanne Mathews");
dt.Rows.Add("Robert Schidner");
string[] names = dt.AsEnumerable().Select(r => r["Name"].ToString()).ToArray();
VB.Net
Dim dt As DataTable = New DataTable()
dt.Columns.Add("Name")
dt.Rows.Add("John Hammond")
dt.Rows.Add("Mudasssar Khan")
dt.Rows.Add("Suzanne Mathews")
dt.Rows.Add("Robert Schidner")
Dim names As String() = dt.AsEnumerable().Select(Function(r) r("Name").ToString()).ToArray()