SqlBulkCopy: Error in ColumnName

I want to implement the use of SqlBulkCopy to reduce the insertion times in a migration I'm doing from a system.

In StrArray(x) I get the name of the columns as they are in the table where I want to insert the information, which I store in a GridView, and in StrArray(w) the name of the columns is exactly the same as in the GridView, this is already stored in the .csv file.

Dim directorio as String = "C:\Proyect\Carga.csv"
Dim sr As StreamReader = New StreamReader(directorio)
Dim line As String = sr.ReadLine()
Dim strArray As String() = line.Split(",")
Dim dt As DataTable = New DataTable()
Dim row As DataRow

   For Each s As String In strArray
        dt.Columns.Add(New DataColumn())
   Next

   Do
     row = dt.NewRow()
     row.ItemArray = line.Split(",")
     dt.Rows.Add(row)
     i = i + 1
     line = sr.ReadLine()
   Loop While Not line = String.Empty

   Dim bc As SqlBulkCopy = New SqlBulkCopy(conn, SqlBulkCopyOptions.KeepIdentity, Nothing)
   Dim x as string = 0

   For w = 1 to StrArray - 1
     bc.ColumnMappings.Add(strArray(w), strArray(x))
     x = x + 1
   Next

   bc.DestinationTableName = "dbo." & Nombre_Tabla & ""
   bc.WriteToServer(dt)

But, when trying to make the insert, it throws an exception:

La ColumnName 'ID_Carga' no coincide con ninguna columna del origen de datos.

Since StrArray(w) and StrArray(x) have exactly the same names in relation Table-Table when using ColumnMappings.Add , Why do you give me that error and how can I solve it?

I'm using SQL Server 2008 R2 in a VS2017 project.