大约有 48,000 项符合查询结果（耗时：0.0541秒） [XML]
How to detect if my shell script is running through a pipe?
How do I detect from within a shell script if its standard output is being sent to a terminal or if it's piped to another process?
...
Detect the Internet connection is offline?
...etermine that the connection is lost by making failed XHR requests.
The standard approach is to retry the request a few times. If it doesn't go through, alert the user to check the connection, and fail gracefully.
Sidenote: To put the entire application in an "offline" state may lead to a lot of ...
MySQL check if a table exists without throwing an exception
...
If you're using MySQL 5.0 and later, you could try:
SELECT COUNT(*)
FROM information_schema.tables
WHERE table_schema = '[database name]'
AND table_name = '[table name]';
Any results indicate the table exists.
From: http://www.electrictoolbox.com/check-if-mysql-table-exis...
How to allow to accept only image files?
...
That should be the selected answer! It just lack a note saying that you still need to check server-side (because of non supporting browser, but also for security)
– Erdal G.
Dec 19 '15 at 13:40
...
Can existing virtualenv be upgraded gracefully?
I have a virtualenv created for Python 2.5 and want to "upgrade" it to Python 2.6.
5 Answers
...
“Use of undeclared type” in Swift, even though type is internal, and exists in same module
...
In my case I had selected 3 targets (Project, UI & Unit tests), I had to deselect UI & Unit tests targets in order to solve this error
– Frakcool
Jan 15 '19 at 21:08
...
The type or namespace name 'Objects' does not exist in the namespace 'System.Data'
...ontext.tt and be nested under your edmx file in Solution Explorer. You can select the templates in Solution Explorer and press the Del key to delete them.
Note: In Web Site projects the templates will not be nested under your edmx file, but listed alongside it in Solution Explorer.
Note: In VB.N...
Replacing some characters in a string with another character
I have a string like AxxBCyyyDEFzzLMN and I want to replace all the occurrences of x , y , and z with _ .
5 Answers
...
How can I get every nth item from a List?
...
}
and you write in a LINQish way
from var element in MyList.GetNth(10) select element;
2nd Edit:
To make it even more LINQish
from var i in Range(0, ((myList.Length-1)/n)+1) select list[n*i];
share
|
...
Store boolean value in SQLite
...TO foo VALUES("0.0");
sqlite> INSERT INTO foo VALUES("1.0");
sqlite> select mycolumn, typeof(mycolumn) from foo;
0|integer
1|integer
0|integer
1|integer
0|integer
1|integer
and some that will fail:
sqlite> INSERT INTO foo VALUES("-1");
Error: constraint failed
sqlite> INSERT INTO foo ...