比如
Dim dlg As New OpenFileDialog '定义一个新的OpenFileDialogdlg.Filter= "Excel文件|*.xls" '设置筛选器
dlg.MultiSelect=true
If dlg.ShowDialog = DialogResult.Ok Then '如果用户单击了确定按钮
For each file as string in dlg.FileNames
Dim mg As New Merger
mg.SourcePath = file
mg.Format = "excel" '指定格式
mg.SourceTableName = "订单" '指定要合并的表
mg.DataTableName = "订单" '指定接收数据的表
mg.Merge() '开始合并
Next
End If