大约有 36,010 项符合查询结果（耗时：0.0305秒） [XML]
Do I set properties to nil in dealloc when using ARC?
...
Short answer: no, you do not have to nil out properties in dealloc under ARC.
Long answer: You should never nil out properties in dealloc, even in manual memory management.
In MRR, you should release your ivars. Nilling out properties means call...
How do synchronized static methods work in Java and can I use it for loading Hibernate entities?
...t approach to ensure thread-safety.
Not really. You should let your RDBMS do that work instead. They are good at this kind of stuff.
The only thing you will get by synchronizing the access to the database is to make your application terribly slow. Further more, in the code you posted you're buildi...
How do I update a Linq to SQL dbml file?
How do I update a Linq to SQL .dbml file?
8 Answers
8
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Differences between Ant and Maven [closed]
...rstand that they are used to automate the building of Java projects, but I do not know where to start from.
9 Answers
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How do I make the first letter of a string uppercase in JavaScript?
How do I make the first letter of a string uppercase, but not change the case of any of the other letters?
94 Answers
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When saving, how can you check if a field has changed?
... so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharField()
__original_name = None
def __init__(self, *args, **kwargs):
super(Person, self)._...
In Bash, how to add “Are you sure [Y/n]” to any command or alias?
...sure? [y/N] " response
case "$response" in
[yY][eE][sS]|[yY])
do_something
;;
*)
do_something_else
;;
esac
Or, for Bash >= version 3.2:
read -r -p "Are you sure? [y/N] " response
if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]
then
do_something
else
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How do I fit an image (img) inside a div and keep the aspect ratio?
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You will need some JavaScript to prevent cropping if you don't know the dimension of the image at the time you're writing the css.
HTML & JavaScript
<div id="container">
<img src="something.jpg" alt="" />
</div>
<script type="text/javascript">
(fu...
How do I get the AM/PM value from a DateTime?
...rom date. But if I want to change AM to PM in any date. Then what should I do ?
– Ajay Sharma
Apr 14 '16 at 6:11
2
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Hand Coded GUI Versus Qt Designer GUI [closed]
...eading about Qt Designer just a few hours ago, which made me wonder : what do people writing real world applications in Qt use to design their GUIs? In fact, how do people design GUIs in general?
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