大约有 48,000 项符合查询结果（耗时：0.0694秒） [XML]
Placing border inside of div and not on its edge
I have a <div> element and I want to put a border on it. I know I can write style="border: 1px solid black" , but this adds 2px to either side of the div, which is not what I want.
...
isset() and empty() - what to use
...er something is set or not use isset.
Empty checks if the variable is set and if it is it checks it for null, "", 0, etc
Isset just checks if is it set, it could be anything not null
With empty, the following things are considered empty:
"" (an empty string)
0 (0 as an integer)
0.0 (0 as a floa...
Practical example where Tuple can be used in .Net 4.0?
...ng for the last 15 years. That's how expression bodied members were added, and now value tuples. Record-style classes narrowly missed the cut back in August (9 months before this comment) for this version of C# 7, and are probably coming out in C# 8. Also note that value tuples offer value equality ...
CSS '>' selector; what is it? [duplicate]
... <div class="inner">...</div>
</div>
</div>
and you declare a css rule in your stylesheet like such:
.outer > div {
...
}
your rules will apply only to those divs that have a class of "middle" since those divs are direct descendants (immediate children) of el...
Logging uncaught exceptions in Python
...d pointed out, sys.excepthook is invoked every time an exception is raised and uncaught. The practical implication of this is that in your code you can override the default behavior of sys.excepthook to do whatever you want (including using logging.exception).
As a straw man example:
>>> i...
Rails create or update magic?
...
Rails 6
Rails 6 added an upsert and upsert_all methods that deliver this functionality.
Model.upsert(column_name: value)
[upsert] It does not instantiate any models nor does it trigger Active Record callbacks or validations.
Rails 5, 4, and 3
Not ...
Last non-empty cell in a column
...
This works with both text and numbers and doesn't care if there are blank cells, i.e., it will return the last non-blank cell.
It needs to be array-entered, meaning that you press Ctrl-Shift-Enter after you type or paste it in. The below is for colu...
Save string to the NSUserDefaults?
...
NSString *valueToSave = @"someValue";
[[NSUserDefaults standardUserDefaults] setObject:valueToSave forKey:@"preferenceName"];
[[NSUserDefaults standardUserDefaults] synchronize];
to get it back later
NSString *savedValue = [[NSUserDefaults standardUserDefaults]
stringForKey:...
passing argument to DialogFragment
...
args.putInt("num", num);
f.setArguments(args);
return f;
}
And get the Args like this
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNum = getArguments().getInt("num");
...
}
See the full example here
http://developer.a...
A cron job for rails: best practices?
...Listener.process_new_messages
puts "done."
end
To execute from the command line, this is just "rake cron". This command can then be put on the operating system cron/task scheduler as desired.
Update this is quite an old question and answer! Some new info:
the heroku cron service I referenced ...