大约有 40,000 项符合查询结果（耗时：0.0413秒） [XML]
Foreign Key to non-primary key
...erformance (as noted above). Does anyone foresee any problems with such a setup?
– Daniel Macias
Oct 19 '15 at 5:54
...
How to change a command line argument in Bash?
...
You have to reset all arguments. To change e.g. $3:
$ set -- "${@:1:2}" "new" "${@:4}"
Basically you set all arguments to their current values, except for the one(s) that you want to change. set -- is also specified by POSIX 7.
The "${...
How do I assign an alias to a function name in C++?
...
Excellent, how about C++98? I have a class w/2 "reset" overloads used to set & reset. Internally, no problem. For external users I wanted to alias as "set" so it's intuitive for context (set a default-constructed, clear()'d etc.; reset working object). Class methods: (1...
How to get error message when ifstream open fails
...use of errno.
On system with POSIX standard:
errno is thread-local; setting it in one thread does not affect its
value in any other thread.
Edit (thanks to Arne Mertz and other people in the comments):
e.what() seemed at first to be a more C++-idiomatically correct way of implementing ...
Chmod recursively
...
You can use chmod with the X mode letter (the capital X) to set the executable flag only for directories.
In the example below the executable flag is cleared and then set for all directories recursively:
~$ mkdir foo
~$ mkdir foo/bar
~$ mkdir foo/baz
~$ touch foo/x
~$ touch foo/y
~...
UIViewController viewDidLoad vs. viewWillAppear: What is the proper division of labor?
.... You should do things that you only have to do once in viewDidLoad - like setting your UILabel texts. However, you may want to modify a specific part of the view every time the user gets to view it, e.g. the iPod application scrolls the lyrics back to the top every time you go to the "Now Playing" ...
Performance - Date.now() vs Date.getTime()
...frozen at the time of its construction (or at whatever time/date it's been set to). That is, if you do this:
var now = new Date();
and then wait a while, a subsequent call to now.getTime() will tell the time at the point the variable was set.
...
setTimeout / clearTimeout problems
...inactivity (user not clicking anywhere). I use jQuery for the rest but the set/clear in my test function are pure javascript.
...
Android ClickableSpan not calling onClick
...
Have you tried setting the MovementMethod on the TextView that contains the span? You need to do that to make the clicking work...
tv.setMovementMethod(LinkMovementMethod.getInstance());
...
What exactly does the Access-Control-Allow-Credentials header do?
...omething that happens passively without any control.
The client code must set the withCredentials property on the XMLHttpRequest to true in order to give permission.
However, this header alone is not enough. The server must respond with the Access-Control-Allow-Credentials header. Responding with ...