大约有 47,000 项符合查询结果（耗时：0.0518秒） [XML]
When should I use nil and NULL in Objective-C?
...ails to acknowledge that [NSNull null] is a very different beast. To quote from NSNull Class Reference, "The NSNull class defines a singleton object used to represent null values in collection objects (which don’t allow nil values)." Also see Using NSNull section of Number and Value Programming To...
How to create a listbox in HTML without allowing multiple selection?
...eate a simple listbox, but one of the requirements is to DISALLOW multiple selection. Most of the code for listboxes goes like this -
...
What does Redis do when it runs out of memory?
...s reached Redis will try to remove keys
# according to the eviction policy selected (see maxmemory-policy).
#
# If Redis can't remove keys according to the policy, or if the policy is
# set to 'noeviction', Redis will start to reply with errors to commands
# that would use more memory, like SET, LPU...
Postgres - FATAL: database files are incompatible with server
...
If you recently upgraded to 11 or 12 from 10.x you can run the below command to upgrade your postgres data directory retaining all data:
brew postgresql-upgrade-database
The above command is taken from the output of brew info postgres
...
Is there a Java API that can create rich Word documents? [closed]
...Word compatible documents (*.doc), as well as corresponding PDF documents, from a Java Web application (a Struts/JSP framework).
OpenOffice UNO also lets you build MS-Office-compatible charts, spreadsheets, presentations, etc. We were able to dynamically build sophisticated Word documents, inclu...
Edit a commit message in SourceTree Windows (already pushed to remote)
...most recent commit) using SourceTree for Windows version 1.5.2.0:
Step 1
Select the commit immediately before the commit that you want to edit.
For example, if I want to edit the commit with message "FOOBAR!" then I need
to select the commit that comes right before it:
Step 2
Right-click on th...
Count number of lines in a git repository
...stat 4b825dc642cb6eb9a060e54bf8d69288fbee4904
This shows the differences from the empty tree to your current working tree. Which happens to count all lines in your current working tree.
To get the numbers in your current working tree, do this:
git diff --shortstat `git hash-object -t tree /dev/...
How can I set the value of a DropDownList using jQuery?
... have described above, yet the range validator keeps failing telling me to select a value (when the value selected is within range). Please see my question stackoverflow.com/questions/3165033/…
– James
Jul 7 '10 at 13:14
...
Long-lasting FB access-token for server to pull FB page info
...page admin)
Head over to the Facebook Graph API Explorer
On the top right, select the FB App you created from the "Application" drop down list
Click "Get Access Token"
Make sure you add the manage_pages permission
Convert this short-lived access token into a long-lived one by making this Graph API c...
How do I detect “shift+enter” and generate a new line in Textarea?
...tarea, in characters, from the start?
function getCaret(el) {
if (el.selectionStart) {
return el.selectionStart;
} else if (document.selection) {
el.focus();
var r = document.selection.createRange();
if (r == null) {
return 0;
}
...