global

问题 Using import aliasing in one file/class, we can reference class library namespaces by assigning our own custom alias like this: ' VB Imports Db = Company.Lib.Data.Objects // C# using Db = Company.Lib.Data.Objects; And then we are able to reference the classes inside of Company.Lib.Data.Objects by using the Db alias that we assigned. Is it possible to do this at the global level so that the alias is applied to the entire solution instead of just one file/class? Currently, we are working with

问题 I have a settings menu in my app which controls the units used throughout the app - metric or US units. So when the user selects one of these in the options in the menu, I want my app to use the chosen units throughout in display and calculations. I plan to do this by storing a boolean in sharedpreferences, then check the value of the boolean every time an activity is opened, and then make the appropriate changes. Is there a better method to go about doing this? Thanks 回答1: Yes you can

问题 Say I have a struct like the following ... typedef struct { int WheelCount; double MaxSpeed; } Vehicle; ... and I have a global variable of this type (I'm well aware of the pitfalls of globals, this is for an embedded system, which I didn't design, and for which they're an unfortunate but necessary evil.) Is it faster to access the members of the struct directly or through a pointer ? ie double LocalSpeed = MyGlobal.MaxSpeed; or double LocalSpeed = pMyGlobal->MaxSpeed; One of my tasks is to

问题 Just confused about global value in Python, here are two piece of code #gl.py import cli a = 1 print "gl 1: %d %d" % (id(a), a) def reset(): global a a = 7 print "reset 1: %d %d" % (id(a), a) if __name__ == '__main__': cli.handler(reset) print "gl 2: %d %d" % (id(a), a) the cli code #cli.py def handler(func): from gl import a print "cli 1: %d %d" % (id(a), a) func() print "cli 2: %d %d" % (id(a), a) The result of execution is $ python gl.py gl 1: 150847672 1 gl 1: 150847672 1 cli 1: 150847672

问题 I know how to fine a global error redirect page in our defined package when exception encountered that just by adding the following configuration in the parent package in struts.xml : <global-results> <result name="error">/error.jsp</result> </global-results> <global-exception-mappings> <exception-mapping exception="java.lang.Exception" result="error" /> </global-exception-mappings> But It seems to not able to catch those exceptions like requested resources, methods, pages are not found, I

问题 I have used a static global variable and a static volatile variable in file scope, both are updated by an ISR and a main loop and main loop checks the value of the variable. here during optimization neither the global variable nor the volatile variable are optimized. So instead of using a volatile variable a global variable solves the problem. So is it good to use global variable instead of volatile? Any specific reason to use static volatile?? Any example program would be appreciable. Thanks

问题 I have a global var foo="some value" and a background process back_func, I want to the background process to access $foo and modify its value, which can be seen by the main process. It's something like the following: #!/bin/bash foo=0 function back_func { foo=$(($foo+1)) echo "back $foo" } (back_func) & echo "global $foo" The result of the above script is global 0 back 1 How could I get the result of global and back are both '1'?, i.e. the back ground process's modification can return back to

问题 This question already has an answer here : Closed 6 years ago . Possible Duplicate: Why is not the keyword global not required in this case? I wonder why I can change global dictionary without global keyword? Why it's mandatory for other types? Is there any logic behind this? E.g. code: #!/usr/bin/env python3 stringvar = "mod" dictvar = {'key1': 1, 'key2': 2} def foo(): dictvar['key1'] += 1 def bar(): stringvar = "bar" print(stringvar) print(dictvar) foo() print(dictvar) print(stringvar) bar(

问题 I just want to use a $variable at several places: not only views and controllers, but also in the routes.php and other configuration files. I don't want things like: use the Config class to load configuration files; use CI's get_instance , et cetera. I just want to declare a given $variable (it could be a constant, but I need it as a variable), and use it absolutely everywhere. In fact... I'd like to know which PHP file in the CI bootstrap is one of the first to be parsed, so I could

问题 This question already has answers here : Closed 6 years ago . Possible Duplicate: Why are global and static variables initialized to their default values? See the code, #include <stdio.h> int a; int main(void) { int i; printf("%d %d\n", a, i); } Output 0 8683508 Here 'a' is initialized with '0', but 'i' is initialized with a 'junk value'. Why? 回答1: Because that's the way it is, according to the C Standard . The reason for that is efficiency: static variables are initialized at compile-time ,