大约有 45,000 项符合查询结果（耗时：0.1901秒） [XML]
`static` keyword inside function?
...$has_run in your example) between multiple calls.
You could use this for different purposes, for example:
function doStuff() {
static $cache = null;
if ($cache === null) {
$cache = '%heavy database stuff or something%';
}
// code using $cache
}
In this example, the if would only b...
Convert data.frame columns from factors to characters
...
Just following on Matt and Dirk. If you want to recreate your existing data frame without changing the global option, you can recreate it with an apply statement:
bob <- data.frame(lapply(bob, as.character), stringsAsFactors=FALSE)
This will convert al...
Insert code into the page context using a content script
...inject the code that wants to access them into the page itself. Same thing if you want to expose your functions/variables to the page context (in your case it's the state() method).
Note in case chrome API is needed:
Since chrome.* APIs can't be used in the exposed page script directly, you have to ...
jQuery click events firing multiple times
...ck handler ain't a one-off throwaway thing. Especially when it's the bulky if-if-if shown in the question. You're supposed to attach it and let it do its work as long as the page lives.
– Marco Faustinelli
Jun 19 '15 at 5:44
...
Javascript - remove an array item by value [duplicate]
...,3,56,6,8,90],
id_tag = 90,
position = tag_story.indexOf(id_tag);
if ( ~position ) tag_story.splice(position, 1);
P.S. For an explanation of that cool ~ tilde shortcut, see this post:
Using a ~ tilde with indexOf to check for the existence of an item in an array.
Note: IE < 9 does ...
Remove redundant paths from $PATH variable
...in:/usr/bin:/sbin:/bin:/usr/games
that would be for the current session, if you want to change permanently add it to any .bashrc, bash.bashrc, /etc/profile - whatever fits your system and user needs.
Note: This is for Linux. We'll make this clear for new coders. (` , ') Don't try to SET = these.
...
How to generate a core dump in Linux on a segmentation fault?
...
This depends on what shell you are using. If you are using bash, then the ulimit command controls several settings relating to program execution, such as whether you should dump core. If you type
ulimit -c unlimited
then that will tell bash that its programs can ...
Check a collection size with JSTL
...
<c:if test="${companies.size() > 0}">
</c:if>
This syntax works only in EL 2.2 or newer (Servlet 3.0 / JSP 2.2 or newer). If you're facing a XML parsing error because you're using JSPX or Facelets instead of JSP, t...
Scale Image to fill ImageView width and keep aspect ratio
...up/down-scale as needed keeping aspect ratio.
scaleType="centerInside"
if the intrinsic width of src is smaller than parent widthwill center the image horizontally
if the intrinsic width of src is larger than parent widthwill make it as wide as the parent allows and down-scale keeping aspect ra...
java.lang.IllegalStateException: The specified child already has a parent
...override OnCreateView in your RouteSearchFragment class, do you have the
if(view != null) {
return view;
}
code segment?
If so, removing the return statement should solve your problem.
You can keep the code and return the view if you don't want to regenerate view data, and onDestroyView()...