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Can an abstract class have a constructor?
... what) {
super(what);
}
}
The superclass Product is abstract and has a constructor. The concrete class TimesTwo has a constructor that just hardcodes the value 2. The concrete class TimesWhat has a constructor that allows the caller to specify the value.
Abstract constructors will fre...
Android update activity UI from service
...tivity UI to show that info.
I did find https://github.com/commonsguy/cw-andtutorials/tree/master/18-LocalService/ this example. Is that a good approch ? Any other examples?
...
How do you avoid over-populating the PATH Environment Variable in Windows?
...
This will parse your %PATH% environment variable and convert each directory to its shortname equivalent and then piece it all back together:
@echo off
SET MyPath=%PATH%
echo %MyPath%
echo --
setlocal EnableDelayedExpansion
SET TempPath="%MyPath:;=";"%"
SET var=
FOR %%a IN (...
ExpandableListView - hide indicator for groups with no children
In an ExpandableListView , is there a way to hide the group indicator for groups with no children?
13 Answers
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How do I use DateTime.TryParse with a Nullable?
...
As Jason says, you can create a variable of the right type and pass that. You might want to encapsulate it in your own method:
public static DateTime? TryParse(string text)
{
DateTime date;
if (DateTime.TryParse(text, out date))
{
return date;
}
else
...
subtle differences between JavaScript and Lua [closed]
... keyword inside generators, giving it support for coroutines.
Lua doesn't convert between types for any comparison operators. In JS, only === and !== don't type juggle.
Lua has an exponentiation operator (^); JS doesn't. JS uses different operators, including the ternary conditional operator (?: vs...
What is the main purpose of setTag() getTag() methods of View?
What is the main purpose of such methods as setTag() and getTag() of View type objects?
7 Answers
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C# elegant way to check if a property's property is null
In C#, say that you want to pull a value off of PropertyC in this example and ObjectA, PropertyA and PropertyB can all be null.
...
Android global variable
...
You can extend the base android.app.Application class and add member variables like so:
public class MyApplication extends Application {
private String someVariable;
public String getSomeVariable() {
return someVariable;
}
...
How to perform file system scanning
...e versions of GO in the near future.
There's actually a function in the standard lib just for this: filepath.Walk.
package main
import (
"path/filepath"
"os"
"flag"
)
type visitor int
// THIS CODE NO LONGER WORKS, PLEASE SEE ABOVE
func (v visitor) VisitDir(path string, f *os.FileInf...