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Dialog throwing "Unable to add window — token null is not for an application” with getApplication()
...ce, which is an object's reference to itself (i.e. reference to the actual allocated memory for storing the object's data). It happens to any allocated memory for which the Garbage Collector (GC) is unable to free up after the allocated memory has outlived its useful lifespan.
Most of the time, whe...
UITableView Cell selected Color?
...ed).
Therefore, if you're using a plain-style table, then you'll need to alloc-init a new UIView having your desired background colour and then assign it to selectedBackgroundView.
Alternatively, you could use:
cell.selectionStyle = UITableViewCellSelectionStyleGray;
if all you wanted was a gr...
Is leaked memory freed up when the program exits?
...o, and thus can no longer free. The OS still keeps track of all the memory allocated to a process, and will free it when that process terminates.
In the vast majority of cases the OS will free the memory - as is the case with normal "flavors" of Windows, Linux, Solaris, etc. However it is important...
What do 'real', 'user' and 'sys' mean in the output of time(1)?
...s'
There are things that your code cannot do from user mode - things like allocating memory or accessing hardware (HDD, network, etc.). These are under the supervision of the kernel, and it alone can do them. Some operations like malloc orfread/fwrite will invoke these kernel functions and that the...
Does the default constructor initialize built-in types?
...tually a source for really strange errors as modern OSs tend to fill newly allocated memory regions with zeroes. If you expect that, it might work the first time. However, as your application keeps running, delete-ing and new-ing objects, you will sooner or later end up in a situation where you expe...
How do I tokenize a string in C++?
...ybe, but then we’re forced to perform (potentially redundant and costly) allocations.
Instead, C++ offers a plethora of ways to split strings based on arbitrarily complex delimiters, but none of them is encapsulated as nicely as in other languages. The numerous ways fill whole blog posts.
At its...
How do I initialize an empty array in C#?
...r of places that return an empty byte array to avoid
// unnecessary memory allocation.
internal static class EmptyArray<T>
{
public static readonly T[] Value = new T[0];
}
(code contract related code removed for clarity)
See also:
Array.Empty source code on Reference Source
Introducti...
Can we open pdf file using UIWebView on iOS?
... in your web view directly:
Objective-C
UIWebView *webView = [[UIWebView alloc] initWithFrame:CGRectMake(10, 10, 200, 200)];
NSURL *targetURL = [NSURL URLWithString:@"https://www.example.com/document.pdf"];
NSURLRequest *request = [NSURLRequest requestWithURL:targetURL];
[webView loadRequest:requ...
Are tuples more efficient than lists in Python?
...les can be reused instead of copied.
3) Tuples are compact and don't over-allocate.
4) Tuples directly reference their elements.
Tuples can be constant folded
Tuples of constants can be precomputed by Python's peephole optimizer or AST-optimizer. Lists, on the other hand, get built-up from scra...
Python - Create a list with initial capacity
...bject %d" % ( i, )
result.append(message)
return result
def doAllocate( size=10000 ):
result=size*[None]
for i in range(size):
message= "some unique object %d" % ( i, )
result[i]= message
return result
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