大约有 47,000 项符合查询结果（耗时：0.0858秒） [XML]
What are 'closures' in .NET?
...
The general feature of closures is implemented in C# by anonymous methods and lambda expressions.
Here's an example using an anonymous method:
using System;
class Test
{
static void Main()
{
Action action = CreateAction();
action();
action();
}
static Act...
Detect if value is number in MySQL
... FROM myTable WHERE concat('',col1 * 1) = col1
It doesn't work for non-standard numbers like
1e4
1.2e5
123. (trailing decimal)
share
|
improve this answer
|
follow
...
How do I execute inserts and updates in an Alembic upgrade script?
...ms.
Note that Alembic provides some basic data functions: op.bulk_insert() and op.execute(). If the operations are fairly minimal, use those. If the migration requires relationships or other complex interactions, I prefer to use the full power of models and sessions as described below.
The followi...
Android: How to enable/disable option menu item on button click?
...enu() method is called
only once, as described above. The
system keeps and re-uses the Menu you
define in this method until your
activity is destroyed. If you want to
change the Options Menu any time after
it's first created, you must override
the onPrepareOptionsMenu() method.
This ...
In C#, how do I calculate someone's age based on a DateTime type birthday?
...
An easy to understand and simple solution.
// Save today's date.
var today = DateTime.Today;
// Calculate the age.
var age = today.Year - birthdate.Year;
// Go back to the year in which the person was born in case of a leap year
if (birthdat...
Checking in packages from NuGet into version control?
...o enable your projects to support pack restore you need to run another command:
Enable-PackageRestore
Now you are ready to commit your code base without the packages folder. The previous command changed your project files so that if packages are missing they get automatically downloaded and added...
Why do you need ./ (dot-slash) before executable or script name to run it in bash?
...Unix, usually, the current directory is not in $PATH.
When you type a command the shell looks up a list of directories, as specified by the PATH variable. The current directory is not in that list.
The reason for not having the current directory on that list is security.
Let's say you're root and...
Hadoop “Unable to load native-hadoop library for your platform” warning
...p.so.1.0.0 was actually compiled on 32 bit.
Anyway, it's just a warning, and won't impact Hadoop's functionalities.
Here is the way if you do want to eliminate this warning, download the source code of Hadoop and recompile libhadoop.so.1.0.0 on 64bit system, then replace the 32bit one.
Steps o...
SQLite error 'attempt to write a readonly database' during insert?
... Also, SELinux (if installed) must not be enforcing. Took me a day and a half to figure that one out.
– Steve V.
Dec 19 '10 at 8:31
1
...
Non-Singleton Services in AngularJS
...eturn a newable function as this begins to break down dependency injection and the library will behave awkwardly, especially for third parties. In short, I am not sure there are any legitimate use cases for non-singleton sevices.
A better way to accomplish the same thing is to use the factory as an...