大约有 40,000 项符合查询结果（耗时：0.0487秒） [XML]
What is Lazy Loading?
...:
...
@property
def total(self):
if not hasattr(self, "_total"):
self._total = self.quantity \
+ sum(bi.quantity for bi in self.borroweditem_set.all())
return self._total
Basically, I have an Item class which represents an item in our inven...
Is the != check thread safe?
...g/Object;
ALOAD 0
GETFIELD test/Test1.a : Ljava/lang/Object;
IF_ACMPEQ L1
...
as we can see it loads field a to local vars twice, it's a non-atomic operation, if a was changed in between by another thread comparison may produce false.
Also, memory visibility problem is relevant here...
C# Regex for Guid
...a-fA-F0-9]{8}[-]?([a-fA-F0-9]{4}[-]?){3}[a-fA-F0-9]{12}[})]?",
@"${ __UUID}",
RegexOptions.IgnoreCase
);
Surely works! And it matches & replaces the following styles, which are all equivalent and acceptable formats for a GUID.
"aa761232bd4211cfaacd00aa0057b243"
"AA761232-BD42-1...
Scala: write string to file in one statement
....write(Paths.get("file.txt"), "file contents".getBytes(StandardCharsets.UTF_8))
I think this is by far the simplest and easiest and most idiomatic way, and it does not need any dependencies sans Java itself.
share
...
Improve INSERT-per-second performance of SQLite
... versions of SQLite - Consider a less paranoid journal mode (pragma journal_mode). There is NORMAL, and then there is OFF, which can significantly increase insert speed if you're not too worried about the database possibly getting corrupted if the OS crashes. If your application crashes the data sho...
force Maven to copy dependencies into target/lib
...ocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>groupId</groupId>
<artifactId>artifactId</artifactId>
<version>1.0</version>
<dependencies>...
How can one display images side by side in a GitHub README.md?
...ssible to add a title to each of the images?
– recipe_for_disaster
Jan 12 at 7:27
This is perfect! As it allows to spe...
Splitting templated C++ classes into .hpp/.cpp files--is it possible?
...
You can do it in this way
// xyz.h
#ifndef _XYZ_
#define _XYZ_
template <typename XYZTYPE>
class XYZ {
//Class members declaration
};
#include "xyz.cpp"
#endif
//xyz.cpp
#ifdef _XYZ_
//Class definition goes here
#endif
This has been discussed in Daniweb
...
Reusable library to get human readable version of file size?
...o require a library" issue by a straightforward implementation:
def sizeof_fmt(num, suffix='B'):
for unit in ['','Ki','Mi','Gi','Ti','Pi','Ei','Zi']:
if abs(num) < 1024.0:
return "%3.1f%s%s" % (num, unit, suffix)
num /= 1024.0
return "%.1f%s%s" % (num, 'Yi', s...
Check whether or not the current thread is the main thread
...be executed on the main thread, you can:
- (void)someMethod
{
dispatch_block_t block = ^{
// Code for the method goes here
};
if ([NSThread isMainThread])
{
block();
}
else
{
dispatch_async(dispatch_get_main_queue(), block);
}
}
...