大约有 40,000 项符合查询结果（耗时：0.0417秒） [XML]
How to save a PNG image server-side, from a base64 data string
...plode(';', $data);
list(, $data) = explode(',', $data);
$data = base64_decode($data);
file_put_contents('/tmp/image.png', $data);
And as a one-liner:
$data = base64_decode(preg_replace('#^data:image/\w+;base64,#i', '', $data));
An efficient method for extracting, decoding, and checking for e...
Safe (bounds-checked) array lookup in Swift, through optional bindings?
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WARNING! Checking arrays this way can be really expensive. The contains method will iterate through all indices thus making this an O(n). A better way is to use the index and count to check the bounds.
– Stefan Vasiljevic
May 7 '...
UITableView is starting with an offset in iOS 7
...ed Aug 22 '13 at 19:05
Mick MacCallum
122k4040 gold badges273273 silver badges274274 bronze badges
answered Aug 22 '13 at 19:02
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Calculate distance between 2 GPS coordinates
...y solution:
#include <math.h>
#include "haversine.h"
#define d2r (M_PI / 180.0)
//calculate haversine distance for linear distance
double haversine_km(double lat1, double long1, double lat2, double long2)
{
double dlong = (long2 - long1) * d2r;
double dlat = (lat2 - lat1) * d2r;
...
Why does the C++ STL not provide any “tree” containers?
...we have
std::map (and std::multimap)
std::set (and std::multiset)
Basically the characteristics of these two containers is such that they practically have to be implemented using trees (though this is not actually a requirement).
See also this question:
C tree Implementation
...
Purpose of returning by const value? [duplicate]
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In the hypothetical situation where you could perform a potentially expensive non-const operation on an object, returning by const-value prevents you from accidentally calling this operation on a temporary. Imagine that + returned a non-const value, and you could write:
(a + b).expensiv...
How to serialize a lambda?
...le)() -> System.out.println("Serializable!");
And the lambda automagically becomes serializable.
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How can I make a UITextField move up when the keyboard is present - on starting to edit?
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isn't it batter to call -(void)setViewMovedUp:(BOOL)movedUp in keyBoardWillSHow and KeyBoardWillHide events!!
– Abduliam Rehmanius
Jun 26 '11 at 4:08
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Regular expression: find spaces (tabs/space) but not newlines
... You'll need to either normalize your strings first (such as by replacing all \u3000 with \u0020), or you'll have to use a character set that includes this codepoint in addition to whatever other whitespace you're targeting, such as [ \t\u3000].
If you're using Perl or PCRE, you have the option of...
Increasing the maximum number of TCP/IP connections in Linux
...local_port_range = 32768 61000
net.ipv4.tcp_fin_timeout = 60
This basically means your system cannot consistently guarantee more than (61000 - 32768) / 60 = 470 sockets per second. If you are not happy with that, you could begin with increasing the port_range. Setting the range to 15000 61000 is...