Only numbers entered afterwards, or numbers which are then edited, will become text numbers. If you decide to enter a number directly as a text string, enter an apostrophe (') first. For example, for years in column headings, you can enter '1999, '2000 and '2001. The apostrophe is not visible in the cell, it only indicates that the entry is to be recognised as a text string and not as a number.
如果您是在单元格中输入了一些常规数字后才将单元格格式改为“文字”，则这些数字仍保留常规数字格式，而不会转换为文字格式。只有在设置了“文字”格式后输入新的数字或编辑现有数字，这些数字才会转换为文字。