大约有 44,000 项符合查询结果（耗时：0.0685秒） [XML]
What does “Object reference not set to an instance of an object” mean? [duplicate]
I am receiving this error and I'm not sure what it means?
8 Answers
8
...
Is there a CSS selector for the first direct child only?
... you posted literally means "Find any divs that are inside of section divs and are the first child of their parent." The sub contains one tag that matches that description.
It is unclear to me whether you want both children of the main div or not. If so, use this:
div.section > div
If you onl...
What does the 'static' keyword do in a class?
...n the example given, main does not know which instance of the Hello class (and therefore which instance of the Clock class) it should refer to. static members can only refer to static members. Instance members can, of course access static members.
Side note: Of course, static members can access ins...
While loop to test if a file exists in bash
... using a Bash (or related) shell by typing 'echo $SHELL'. I think that CSH and TCSH use a slightly different semantic for this loop.
share
|
improve this answer
|
follow
...
Relative paths based on file location instead of current working directory [duplicate]
...o is get the absolute path of the script (available via ${BASH_SOURCE[0]}) and then use this to get the parent directory and cd to it at the beginning of the script.
#!/bin/bash
parent_path=$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )
cd "$parent_path"
cat ../some.text
This will make your s...
How do I discard unstaged changes in Git?
...h about it.
After that, you can drop that stash with a git stash drop command if you like.
share
|
improve this answer
|
follow
|
...
Computed read-only property vs function in Swift
...operties for just that: properties; meaning simple values that you can get and/or set. I use functions (or methods) when actual work is being done. Maybe something has to be computed or read from disk or from a database: In this case I use a function, even when only a simple value is returned. That ...
How to attach debugger to iOS app after launch?
I have an issue I am troubleshooting which occurs very infrequently and doesn't seem to happen when I have things running under Xcode.
...
How can I open a cmd window in a specific location?
...
Try out this "PowerToy" from Microsoft:
Open Command Window Here
This PowerToy adds an "Open Command
Window Here" context menu option on
file system folders, giving you a
quick way to open a command window
(cmd.exe) pointing at the selected
folder.
EDIT : T...
What is the largest TCP/IP network port number allowable for IPv4?
...ions. Microsoft wrote an interesting Technet article about how to diagnose and avoid it in Windows environments: blogs.technet.microsoft.com/askds/2008/10/29/…
– JessieArr
Jul 13 '16 at 20:04
...