大约有 44,000 项符合查询结果（耗时：0.0446秒） [XML]
Detect backspace in empty UITextField
...essed in the iPhone keyboard on a UITextField that is empty? I want to know when Backspace is pressed only if the UITextField is empty.
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Is there a way to programmatically scroll a scroll view to a specific edit text?
...ng the UI thread, when you can, after you've done all you had to do before now, do this (scroll). You're basically putting the scroll in the queue and letting the thread do it when it can, respecting the order of things it was doing before you requested it.
– Martin Marconcini
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Drop unused factor levels in a subsetted data frame
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It is a known issue, and one possible remedy is provided by drop.levels() in the gdata package where your example becomes
> drop.levels(subdf)
letters numbers
1 a 1
2 b 2
3 c 3
> levels(dro...
How to highlight and color gdb output during interactive debugging?
... set inferior-tty command. ex. from my .gdbinit set inferior-tty /dev/tty2 now your stdout will not mess up $gdb -tui.
– netskink
Jan 18 '16 at 0:02
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Disable ActiveRecord for Rails 4
... I created an application with rails new my_app -O a month ago. Now I want the active record back. What are files/gems/configuration I need to add now?
– Jak
Mar 25 '15 at 20:09
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Does a foreign key automatically create an index?
...en two tables - that has nothing to do with an index per se.
But it is a known fact that it makes a lot of sense to index all the columns that are part of any foreign key relationship, because through a FK-relationship, you'll often need to lookup a relating table and extract certain rows based on ...
How to get C# Enum description from value? [duplicate]
...urn Enumerations.GetEnumDescription((Enum)(object)((TEnum)EnumValue));
}
now I can write:
MyEnum my = MyEnum.HereIsAnother;
string description = my.ToDescription();
System.Diagnostics.Debug.Print(description);
Note: replace "Enumerations" above with your class name
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What's the difference between Ruby's dup and clone methods?
...48 (Rails cookie handling) then you can easily get an error when they unbeknownst to you they clone it and then attempt to modify the clone. duping your frozen value and passing that in allows you to at least guarantee that no one accidentally modifies your constant, without breaking Rack here.
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Converting .NET DateTime to JSON [duplicate]
...r, that's fine too, but if that means you're doing substring + validation, now you're into multiple lines of code (hopefully in a separate function) which means more things that can go wrong and more programmer time spent (programmers being more expensive than CPUs).
– gregmac
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How to install plugins to Sublime Text 2 editor?
...me, type in install and press enter, then search for emmet.
EDIT: You can now also press Ctrl + Shift + P right away and use the command 'Install Package Control' instead of following the install instructions. (Tested on Build 3126)
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