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Android 4.3 Bluetooth Low Energy unstable
...sting 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.
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Preserving order with LINQ
...ts, but the elements which are returned will be in the same order.
If you convert to a different data structure, e.g. with ToLookup or ToDictionary, I don't believe order is preserved at that point - but that's somewhat different anyway. (The order of values mapping to the same key is preserved for...
How do I create directory if it doesn't exist to create a file?
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var filePath = context.Server.MapPath(Convert.ToString(ConfigurationManager.AppSettings["ErrorLogFile"]));
var file = new FileInfo(filePath);
file.Directory.Create(); If the directory already exists, this method does nothing.
var sw = new StreamWriter(filePath...
Displaying the build date
... have an app displaying the build number in its title window. That's well and good except it means nothing to most of the users, who want to know if they have the latest build - they tend to refer to it as "last Thursday's" rather than build 1.0.8.4321.
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Understanding how recursive functions work
...grok yet. Filtering out all of the (extremely clever) "In order to understand recursion, you must first understand recursion." replies from various online threads I still am not quite getting it.
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What does [].forEach.call() do in JavaScript?
... Array, it is possible to iterate over it
with forEach(). It can also be converted to a real Array using
Array.from().
However, some older browsers have not implemented NodeList.forEach()
nor Array.from(). This can be circumvented by using
Array.prototype.forEach() — see this document...
How to combine two or more querysets in a Django view?
...ne, since itertools is implemented in C. It also consumes less memory than converting each queryset into a list before concatenating.
Now it's possible to sort the resulting list e.g. by date (as requested in hasen j's comment to another answer). The sorted() function conveniently accepts a generat...
Fetch first element which matches criteria
...row the NPE. To prevent that from happening, use orElse() instead of get() and provide a fallback object (like orElse(new Station("dummy", -1)), or store the result of findFirst() in a variable and check it with isEmpty() before calling get()
– ifloop
Jan 24 '1...
How do I add more members to my ENUM-type column in MySQL?
...ySQL is notorious for allowing garbage into ENUM columns. It will silently convert non-conforming values to empty strings, for instance. Are you 100% sure you don't have any offending values? No empty strings? No leading or trailing whitespace? Case differences? Accented characters?
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Create dynamic URLs in Flask with url_for()
...Just so that it is clearer, if you have @app.route("/<a>/<b>") and def function(a,b): ... as its function, then you should use url_for and specify its keyword arguments like this: url_for('function', a='somevalue', b='anothervalue')
– jarrettyeo
May...