大约有 32,000 项符合查询结果（耗时：0.0587秒） [XML]
Java Singleton and Synchronization
...e loaded when it is needed. That means that the first time getInstance is called, InstanceHolder will be loaded and instance will be created, and since this is controlled by ClassLoaders, no additional synchronization is necessary.
...
Which icon sizes should my Windows application's icon include?
... 24, 32, 40, 48, 64, 96, 128 and 256. Then I checked which image is shown. All these were done with normal 96dpi. If using a larger DPI, the larger sizes may be used (only checked this a bit in Windows 7). The results:
Windows XP:
Explorer views:
Details / List: 16
Icons: 32
Tiles / Thumbnails: 48...
How do I create test and train samples from one dataframe with pandas?
...
In the newest SciKit version you need to call it now as: from sklearn.cross_validation import train_test_split
– horseshoe
Mar 22 '17 at 9:32
...
“Parser Error Message: Could not load type” in Global.asax
...
Your local web server is running different code than what you're actually working on. Ensure you have stopped debugging, stop your local web server, clean and rebuild as Peter suggested, double-check your global.asax and global.asax.cs, and try again.
If this doesn't work and you are using lo...
How do I get SUM function in MySQL to return '0' if no values are found?
...iddle.com/#!2/d1542/3/0
More Information:
Given three tables (one with all numbers, one with all nulls, and one with a mixture):
SQL Fiddle
MySQL 5.5.32 Schema Setup:
CREATE TABLE foo
(
id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
val INT
);
INSERT INTO foo (val) VALUES
(null),(1),(n...
Cannot simply use PostgreSQL table name (“relation does not exist”)
... is defined with a mixed-case spelling, and you're trying to query it with all lower-case.
In other words, the following fails:
CREATE TABLE "SF_Bands" ( ... );
SELECT * FROM sf_bands; -- ERROR!
Use double-quotes to delimit identifiers so you can use the specific mixed-case spelling as the tab...
What is your naming convention for stored procedures? [closed]
...ow the database is at 700 procedures plus, it becomes a lot harder to find all procedures on a specific object. For example i now have to search 50 odd Add procedures for the Product add, and 50 odd for the Get etc.
Because of this in my new application I'm planning on grouping procedure names by o...
Why should we typedef a struct so often in C?
...As Greg Hewgill said, the typedef means you no longer have to write struct all over the place. That not only saves keystrokes, it also can make the code cleaner since it provides a smidgen more abstraction.
Stuff like
typedef struct {
int x, y;
} Point;
Point point_new(int x, int y)
{
Point a...
How to select option in drop down protractorjs e2e tests
...
I had a similar problem, and eventually wrote a helper function that selects dropdown values.
I eventually decided that I was fine selecting by option number, and therefore wrote a method that takes an element and the optionNumber, and selects that optionNumb...
Where is Java's Array indexOf?
I must be missing something very obvious, but I've searched all over and can't find this method.
13 Answers
...