展开文字后，是否可以使用侧面按钮将文字标记为进一步折叠/展开？

Question

在我展开折叠的文本区域后，它不能再用侧面按钮折叠，因为它消失了，可以留在那儿以便我再次折叠吗？

Answer 1

The fold arrows that Sublime adds to the gutter only appear based on the indentation of your code; specifically there needs to be at least two lines below a line that are both indented (how much indent doesn't matter as long as there is any) for that line to gain a fold arrow.

As visualized in your screen shots, there is no indent and so you're forced to use manual key bindings in order to fold code.