大约有 44,000 项符合查询结果（耗时：0.0551秒） [XML]
windows batch SET inside IF not working
...y.
Therefore the delayedExpansion syntax exists, it uses ! instead of % and it is evaluated at execution time, not parse time.
Please note that in order to use !, the additional statement setlocal EnableDelayedExpansion is needed.
setlocal EnableDelayedExpansion
set var1=true
if "%var1%"=="true...
How is Generic Covariance & Contra-variance Implemented in C# 4.0?
...t I heard some news that C# 4.0 is announced to support Generic covariance and contra-variance. That is, List<string> can be assigned to List<object> . How could that be?
...
Get distance between two points in canvas
I have canvas drawing tab and want lineWidth to be based on distance between two last mousemove coordinate updates. I will make translation of distance to width myself, I just need to know how to get distance between those points (I already have coordinates of those pointes).
...
How to randomly sort (scramble) an array in Ruby?
...
And if you want to implement it yourself: en.wikipedia.org/wiki/Fisher-Yates_shuffle
– Joey
Nov 29 '09 at 18:52
...
Check time difference in Javascript
...objects to get their difference:
// use a constant date (e.g. 2000-01-01) and the desired time to initialize two dates
var date1 = new Date(2000, 0, 1, 9, 0); // 9:00 AM
var date2 = new Date(2000, 0, 1, 17, 0); // 5:00 PM
// the following is to handle cases where the times are on the opposite si...
How do I subtract minutes from a date in javascript?
...
But doesn't handle when you add minutes. To correctly handle when you add minutes, you should use .getTime(). Example: var myStartDate = new Date(myEndDateTime.getTime() + durationInMinutes * MS_PER_MINUTE);
– Gabrie...
Stop the 'Ding' when pressing Enter
I have a very simple Windows Forms Application. And, in Windows (or, atleast Windows Forms Applications), when you press Enter while inside a Single-line TextBox Control, you hear a Ding. It's an unpleasent sound, that indicated you cannot enter a newline, because it is a single-line TextBox.
...
PostgreSQL error: Fatal: role “username” does not exist
...en done with operating as system user postgres.
Or execute the single command createuser as postgres with sudo, like demonstrated by drees in another answer.
The point is to use the operating system user matching the database role of the same name to be granted access via ident authentication. pos...
Formatting a number with exactly two decimals in JavaScript
...cation (ECMA402). It has pretty good browser support, including even IE11, and it is fully supported in Node.js.
const formatter = new Intl.NumberFormat('en-US', {
minimumFractionDigits: 2,
maximumFractionDigits: 2,
});
console.log(formatter.format(2.005)); // "2.01"
console.log(for...
How to find serial number of Android device?
I need to use a unique ID for an Android app and I thought the serial number for the device would be a good candidate. How do I retrieve the serial number of an Android device in my app ?
...