对于Xocde 12.0 beta 5:

在底部你会看到字体族。

去XCode >首选项>字体& 颜色 双击字体条目以获得字体检查器窗口 选择您想增加/减少大小的所有字体条目 在字体检查器窗口中选择相同的字体(例如:All Fonts > Menlo > Regular > 14)

小心，因为没有撤销!

更新!看Xcode 9来拯救你! 现在你可以使用cmd +来增加Xcode 9的字体。 你花了5个主要版本才得到它，苹果!但迟到总比不到好。

我算出来了，不过不是很直观。

首先是一些痛点

When You try to change the font size directly using edit -> format -> font, nothing happens! - Not a good UX ... moreover why play dumb when you can tell user that they are using default or "System-owned" theme and they cannot change it? - Bad Design and more bad UX ... Why keep this option (Cmd t) alive, which by the way is most standard way to increase font size across most well behaved mac apps, if you do not want user to change the font this way? In Xcode preferences, when you try to change the font size by clicking on "fonts and colors", thats when XCode gives a pop-up saying what needs to be done. Also making a duplicate and then changing the fonts and colors is a lot of work rather than giving a button that says "Restore to Defaults" if Apple is so worried about the user messing up the default settings!

解决方案是-你需要复制主题，然后修改你刚刚制作的副本，并应用该副本-唷!

你可以使用以下方法:

出版社xcode - >首选项 选择字体和颜色 选择列表中的任意字体并按cmd+a(选择所有字体) 选择窗口底部所有编辑器字体的字体大小

以下步骤:

去xcode_preferences->然后选择字体和颜色->选择所有的文本选项->点击字体部分，改变你想要的字体

对于Xcode版本12.3及以上(不确定它是否适用于一些旧版本，但你可以尝试一下)

Xcode

-> Preferences -> Themes 
-> Select your favourite theme on left panel 
-> SourceEditor 
-> Select All (`cmd + A`) 
-> Click on T option 
-> Select size