大约有 40,000 项符合查询结果（耗时：0.0554秒） [XML]
Detect permission of camera in iOS
...
Check the AVAuthorizationStatus and handle the cases properly.
NSString *mediaType = AVMediaTypeVideo;
AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:mediaType];
if(authStatus == AVAuthorizationStatusAuthorized) {
// do your logic
} else if(authStatus...
Why is x86 ugly? Why is it considered inferior when compared to others? [closed]
...rip through memory more frequently than would otherwise be necessary. The extra instructions needed to do this take execution resources that could be spent on useful work, although efficient store-forwarding keeps the latency low. Modern implementations with register renaming onto a large physical...
Using “super” in C++
... the first time C++ was standardized.
Dag Bruck proposed this extension, calling the base class "inherited." The proposal mentioned the multiple inheritance issue, and would have flagged ambiguous uses. Even Stroustrup was convinced.
After discussion, Dag Bruck (yes, the same person making the p...
Styling multi-line conditions in 'if' statements? [closed]
... after a \ it might not show in your editor, and the code becomes syntactically incorrect.
– Eric O Lebigot
Jan 14 '11 at 10:26
...
Why is UICollectionViewCell's outlet nil?
...er, binded views on it to the class, and then when I want to use and set a string to the label on the string, tha label has a nil value.
...
How to check size of a file using Bash?
...
[ -n file.txt ] doesn't check its size, it checks that the string file.txt is non-zero length, so it will always succeed.
If you want to say "size is non-zero", you need [ -s file.txt ].
To get a file's size, you can use wc -c to get the size (file length) in bytes:
file=file.txt
...
What is the pythonic way to avoid default parameters that are empty lists?
...he preferred way in this example is to say: if working_list is None . The caller might have used an empty list-like object with a custom append.
– tzot
Dec 14 '08 at 12:45
5
...
Allowed memory size of 33554432 bytes exhausted (tried to allocate 43148176 bytes) in php
...gram in PHP in a way that consumes memory faster than you realise. Copying strings, arrays and objects instead of using references will do it, though PHP 5 is supposed to do this more automatically than in PHP 4. But dealing with your data set in entirety over several steps is also wasteful compared...
Why do x86-64 instructions on 32-bit registers zero the upper part of the full 64-bit register?
...benefit of zero extension would actually be required more, so it saves the extra line of code mov rax, 0. By guaranteeing it will always be zero extended to 64 bits, the compilers can work with this axiom in mind whilst in mov rdx, rax, rax only has to wait for its single dependency, meaning it can ...
Is there a way to stop Google Analytics counting development work as hits?
...se of Google Analytics. Only problem is that I am sure that it is counting all my development work as hits. Seeing as I probably see some of those pages a hundred times a day it will really skew my readings. Is there a way to turn it off from a particular IP address or is this something that should ...