How to patch module files with netbeans 7.4? Trying to apply patch https://drupal.org/files/webform_preview-435232_1.patch
to webform 7.x-3.19 via Netbeans tool - apply dif-patch. Downloaded this patch and put into drupal root directory. When applying patch to module files see the following: "The patch cannot be applied in the selected context". Module files are in Netbeans project and all paths are properly set. The code to which patch changes are applied exists in the target file, so what else problems can be? 

Thanks!
If you duplicate the file in Netbeans that gets patched (this is important that you do this on the file, NOT the project) then right click on it under Tools -> Apply Diff Patch then select your patch file. It should then say everything went as planned and allow you a summary.

You will need to repeat this for every file in the patch, or you can just apply it using Git or one of the other methods listed.