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Android 4.3 Bluetooth Low Energy unstable
...gy (testing on the Nexus 4). After getting started with the official BLE APIs in Android 4.3, I have noticed that after I connect a device for the first time I am rarely able to successfully connect to / communicate with that device or any other device again.
...
What are some (concrete) use-cases for metaclasses?
...r and an offscreen plotting wrapper, I found it was more efficient to do this via metaclasses, wrapping the appropriate methods, than to do something like:
class PlottingInteractive:
add_slice = wrap_pylab_newplot(add_slice)
This method doesn't keep up with API changes and so on, but one that...
Which CheckedListBox event triggers after a item is checked?
I have a CheckedListBox where I want an event after an item is checked so that I can use CheckedItems with the new state.
...
Java ArrayList copy
I have an ArrayList l1 of size 10. I assign l1 to new list reference type l2 . Will l1 and l2 point to same ArrayList object? Or is a copy of the ArrayList object assigned to l2 ?
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Why C# fails to compare two object types with each other but VB doesn't?
...g two references which are the result of boxing conversions, so those are distinct references.
EDIT: With types which overload the ==, you can get different behaviour - but that's based on the compile-time type of the expressions. For example, string provides ==(string, string):
string x = new str...
implements Closeable or implements AutoCloseable
... any other resources which needs to be closed.
In your implementation, it is enough to call pw.close(). You should do this in a finally block:
PrintWriter pw = null;
try {
File file = new File("C:\\test.txt");
pw = new PrintWriter(file);
} catch (IOException e) {
System.out.println("bad t...
How can I replace a newline (\n) using sed?
...
Use this solution with GNU sed:
sed ':a;N;$!ba;s/\n/ /g' file
This will read the whole file in a loop, then replaces the newline(s) with a space.
Explanation:
Create a label via :a.
Append the current and next line to the pa...
Singletons vs. Application Context in Android?
Recalling this post enumerating several problems of using singletons
and having seen several examples of Android applications using singleton pattern, I wonder if it's a good idea to use Singletons instead of single instances shared through global application state (subclassing android.os.Applicat...
Detect URLs in text with JavaScript
...
First you need a good regex that matches urls. This is hard to do. See here, here and here:
...almost anything is a valid URL. There
are some punctuation rules for
splitting it up. Absent any
punctuation, you still have a valid
URL.
Check the RFC carefull...
How to call an external command?
...cess
subprocess.run(["ls", "-l"])
The advantage of subprocess vs. system is that it is more flexible (you can get the stdout, stderr, the "real" status code, better error handling, etc...).
The official documentation recommends the subprocess module over the alternative os.system():
The subpr...