Selecting all content of layers in a folder

I have scoured the Adobe support and web for an answer to this question: How does one select all of the combined contents of layers within a folder? I was figuring ctrl-click on the folder icon would do it, as that's most similar to ctrl-clicking a layer's thumbnail to select all of its content. But alas, no. Is there a one-click way to do this? If not, why not? With dejection, I will appreciate multi-click solutions. Thanks for your time.

- DK