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Accessing UI (Main) Thread safely in WPF
... example:
class MyViewModel
{
private readonly SynchronizationContext _syncContext;
public MyViewModel()
{
// we assume this ctor is called from the UI thread!
_syncContext = SynchronizationContext.Current;
}
// ...
private void watcher_Changed(object send...
count(*) vs count(column-name) - which is more correct? [duplicate]
... difference is:
COUNT(*) will count the number of records.
COUNT(column_name) will count the number of records where column_name is not null.
Therefore COUNT(*) is what you should use. If you're using MyISAM and there is no WHERE clause, then the optimiser doesn't even have to look at the tabl...
Python 3.x rounding behavior
...l.Decimal('3.5').quantize(decimal.Decimal('1'),
rounding=decimal.ROUND_HALF_UP)
>>> Decimal('4')
>>> decimal.Decimal('2.5').quantize(decimal.Decimal('1'),
rounding=decimal.ROUND_HALF_EVEN)
>>> Decimal('2')
>>> decimal.Decimal('3.5').quantize(decimal...
How to deselect a selected UITableView cell?
...ndexPath:indexPath animated:YES];
}
Swift 3.0:
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
//Change the selected background view of the cell.
tableView.deselectRow(at: indexPath, animated: true)
}
...
What is a bus error?
...
In my case, a method static_casted a void * parameter to an object that stores a callback (one attribute points to the object and the other to the method). Then the callback is called. However, what was passed as void * was something completely differe...
If Python is interpreted, what are .pyc files?
...on at least. Also I wonder what Cython is.
– personal_cloud
Sep 29 '17 at 15:56
...
Difference between Django's annotate and aggregate methods?
... in the queryset.
Aggregation
>>> Book.objects.aggregate(average_price=Avg('price'))
{'average_price': 34.35}
Returns a dictionary containing the average price of all books in the queryset.
Annotation
>>> q = Book.objects.annotate(num_authors=Count('authors'))
>>> q[...
Why is the gets function so dangerous that it should not be used?
...need to use a wrapper around fgets() that deletes the newline:
char *fgets_wrapper(char *buffer, size_t buflen, FILE *fp)
{
if (fgets(buffer, buflen, fp) != 0)
{
size_t len = strlen(buffer);
if (len > 0 && buffer[len-1] == '\n')
buffer[len-1] = '\0';
...
Pass Array Parameter in SqlCommand
...The following command creates a table type for integers:
create type int32_id_list as table (id int not null primary key)
2. Implement helper methods
public static SqlCommand AddParameter<T>(this SqlCommand command, string name, IEnumerable<T> ids)
{
var parameter = command.CreateP...
PHP Regex to get youtube video ID?
...
Use parse_url() and parse_str().
(You can use regexes for just about anything, but they are very easy to make an error in, so if there are PHP functions specifically for what you are trying to accomplish, use those.)
parse_url takes...