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Factory pattern in C#: How to ensure an object instance can only be created by a factory class?
...some check before creating an object, probably in its constructor. This is all okay until I decide I want to make this check be a part of the business logic. So, how can I arrange for a business object to be creatable only through some method in my business logic class but never directly? The first ...
How to return result of a SELECT inside a function in PostgreSQL?
... -- potential ambiguity
END
$func$ LANGUAGE plpgsql;
Call:
SELECT * FROM word_frequency(123);
Explanation:
It is much more practical to explicitly define the return type than simply declaring it as record. This way you don't have to provide a column definition list with eve...
How to trigger event when a variable's value is changed?
...e you want to create a property.
public int MyProperty
{
get { return _myProperty; }
set
{
_myProperty = value;
if (_myProperty == 1)
{
// DO SOMETHING HERE
}
}
}
private int _myProperty;
This allows you to run some code any time the pr...
Sharing a result queue among several processes
... can I share a queue with asynchronous worker processes started with apply_async ? I don't need dynamic joining or anything else, just a way for the workers to (repeatedly) report their results back to base.
...
List of tables, db schema, dump etc using the Python sqlite3 API
...te("SELECT name FROM sqlite_master WHERE type='table';")
print(cursor.fetchall())
Watch out for my other answer. There is a much faster way using pandas.
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How to find where gem files are installed
I can finds gems that are installed using gem list , but it doesn't show me where the gems are installed.
10 Answers
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How to Apply Gradient to background view of iOS Swift App
...ems you may face with this is that when you add a sublayer it may sit over all your other items, labels, image, etc. To overcome this create another view that sits below everything and set its constraints to that of the container you want the gradient in. Then set the gradient to be applied to this ...
Call static method with reflection
...
I prefer simplicity...
private void _InvokeNamespaceClassesStaticMethod(string namespaceName, string methodName, params object[] parameters) {
foreach(var _a in AppDomain.CurrentDomain.GetAssemblies()) {
foreach(var _t in _a.GetTypes()) {
...
CMFCTabCtrl的使用、颜色样式调整 - C/C++ - 清泛网 - 专注C/C++及内核技术
...建一个CMFCTabCtrl，并给其添加4个CEdit:
CRect rectTab;
CEdit m_wnd1;
CEdit m_wnd2;
CEdit m_wnd3;
CEdit m_wnd4;
CMFCTabCtrl m_wndTab;
m_wndTabLoc.GetWindowRect (&rectTab);
ScreenToClient (&rectTab);
m_wndTab.Create (CMFCTabCtrl::STYLE_3D, rectTab, this, 1,
CMFCTabCtrl::...
Mongodb Explain for Aggregation framework
...ther manipulation will be in-memory (possibly using temporary files if the allowDiskUse option is set).
Optimizing pipelines
In general, you can optimize aggregation pipelines by:
Starting a pipeline with a $match stage to restrict processing to relevant documents.
Ensuring the initial $match / ...