OpenFileDialog打开多种类型的文件

1.多种类型可以一起选择

OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Filter = "(excel文件)|*.xls;*.xlsx";

2.单类型选择

openFileDialog.Filter = ".xls|*.xls|.xlsx|*.xlsx";

3.所有类型

openFileDialog.Filter = "*|*";