> For the complete documentation index, see [llms.txt](https://overleaf-pro.ayaka.space/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://overleaf-pro.ayaka.space/latex/zh-tw/zhi-shi-ku/163-why-does-it-sometimes-take-a-lot-of-time-to-show-the-pdf-preview.md).

# 為什麼顯示 PDF 預覽有時需要很長時間？

這可能是因為您正在編輯的文件中有錯誤——只有當文件能成功編譯時，預覽才會更新。任何錯誤都會使預覽無法更新，而它會持續顯示上一次成功編譯的結果，直到錯誤被修正。

您可以將滑鼠移到預覽右上角的「error」一詞上，查看文件中的任何錯誤。舉例來說，一個常見的錯誤是需要把數學符號放在美元符號中，例如 $$\phi$$ 而不是只寫 \phi。

如果即使錯誤已解決，PDF 預覽仍未更新，請 [告訴我們](https://www.overleaf.com/contact) 我們會幫您查看。


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