How does win7 not open the file directly to copy the contents of the file

In many cases, there are a lot of words in some files. You have to select all and copy them for a long time, or you want to integrate the contents of all the files together, you need to open them one by one and then copy them. There is certainly no need to directly open the file for copying.
1
The contents of the copied file must be placed in a folder. You need to go to the registry to locate the copied content to a file.
Open the Registry Editor, navigate to: HKEY_CLASSES_ROOTtxtfileshell, create a new item, name it: copycontents, and change its default value to: “copy text content”.
2
In the copycontents item, create a new command item, the value is changed to: cmd /c clip < "%1".
3
OK to save and exit the Registry Editor. Feel free to choose a txt text file, click on the right button and try it out.
Modify the registry to be restarted before it can take effect.
4
Small details of copying
Because you don't open the file and copy it directly, it may cause a lot of content inside the clipboard. At this time we need to empty the clipboard, the easy way is to just copy a word and copy it.