大约有 43,000 项符合查询结果（耗时：0.0724秒） [XML]
Do HttpClient and HttpClientHandler have to be disposed between requests?
System.Net.Http.HttpClient and System.Net.Http.HttpClientHandler in .NET Framework 4.5 implement IDisposable (via System.Net.Http.HttpMessageInvoker ).
...
Does MySQL ignore null values on unique constraints?
...sult:
x
NULL
NULL
1
This is not true for all databases. SQL Server 2005 and older, for example, only allows a single NULL value in a column that has a unique constraint.
share
|
improve this answ...
How do I set cell value to Date and apply default Excel date format?
...requirement to create entire .xls files in-memory (still using Apache POI) and then write them to a file at the end. The only problem standing in my way is the handling of cells with dates.
...
Why not abstract fields?
...Child constructor would be trying to use a non-existent noargs constructor and that is a compilation error (not a warning).
– Stephen C
Feb 6 '10 at 0:15
...
How to properly add cross-site request forgery (CSRF) token using PHP
...o add some security to the forms on my website. One of the forms uses AJAX and the other is a straightforward "contact us" form. I'm trying to add a CSRF token. The problem I'm having is that the token is only showing up in the HTML "value" some of the time. The rest of the time, the value is empty....
What arguments are passed into AsyncTask?
I don't understand what I am supposed to put in here and where these arguments end up? What exactly should I put, and where exactly will it go? Do I need to include all 3 or can I include 1,2,20?
...
How does deriving work in Haskell?
...-). This is to say that automatic deriving is baked into the Haskell spec, and every compiler can choose to implement it in its own way. There's lots of work on how to make it extensible however.
Derive is a tool for Haskell to let you write your own deriving mechanisms.
GHC used to provide a deri...
Are memory leaks ever ok? [closed]
...ever OK to do this?" but rather "Is there ever a good reason to do this?" And "hunting down that memory leak is a pain" isn't a good reason.
I like to keep things simple. And the simple rule is that my program should have no memory leaks.
That makes my life simple, too. If I detect a memory lea...
What exactly do “IB” and “UB” mean?
I've seen the terms "IB" and "UB" used several times, particularly in the context of C++. I've tried googling them, but apparently those two-letter combinations see a lot of use. :P
...
What are the mechanics of short string optimization in libc++?
...word) == sizeof(void*). You have correctly dissected the long/short flag, and the size field in the short form.
what value would __min_cap, the capacity of short strings, take for different architectures?
In the short form, there are 3 words to work with:
1 bit goes to the long/short flag.
...