I have the following Global class file:
Global.cs
public static class Global
{
private static string _globalVar = "";
public static string GlobalVar
{
get { return _globalVar; }
set { _globalVar = value; }
}
}
I set the new value of string GlobarVar in Form1.cs as '1234'.
Form1.cs
public Form1()
{
InitializeComponent();
Global.GlobalVar = "1234";
}
I tried to display the value to Form2.cs using the message box
public Form2()
{
InitializeComponent();
MessageBox.Show(Global.GlobalVar); // displays blank values
}
Am I missing something?
Four options:
You're not constructing Form1 before you construct Form2
Something else is setting Global.GlobalVar back to null or an empty string
Your forms are in different app domains, so they'll have entirely separate Global types
You're running the application twice; static variables don't live on across different processes
It's hard to tell which of these is the case, but personally I'd try to avoid using global state to start with. It's a pain for testability and reasoning about how your program works.
Try your property page (file Global.cs) like these:
public class Global
{
private static string _globalVar;
public string GlobalVar
{
get { return _globalVar; }
set { _globalVar = value; }
}
}
Related
I have WPF application and my work method play my files in different threads
This is my Global variable that update my UI:
public static int _totalFilesSent;
Now because i am implement INotifyPropertyChanged in my model i have also this:
public static int TotalFilesSent
{
get { return _totalFilesSent; }
set
{
_totalFilesSent = value;
OnStaticlPropertyChanged("TotalFilesSent");
}
}
(i didn't add the event function because this is not relevant here).
So every time i am update my Global variable this way:
Interlocked.Increment(ref _totalFilesSent );
Now because i need to update my UI with my INotifyPropertyChanged event i need to use TotalFilesSent instead of _totalFilesSent but in this way i got this compilation error:
A property, indexer or dynamic member access may not be passed as an
out or ref parameter.
What does it mean and how can i solved it ?
You may easily raise the StaticPropertyChanged event after calling Interlocked.Increment:
private static int _totalFilesSent;
public static int TotalFilesSent
{
get { return _totalFilesSent; }
}
public static void IncrementTotalFilesSent()
{
Interlocked.Increment(ref _totalFilesSent);
OnStaticPropertyChanged("TotalFilesSent");
}
Having a test similar to this:
public class myClass
{
public int speed100index = 0;
private List<int> values = new List<int> { 200 };
public int Speed100
{
get
{
return values[speed100index];
}
}
}
[TestClass]
public class UnitTest1
{
[TestMethod]
public void TestMethod1()
{
var fixture = new Fixture();
var sut = fixture.Create<myClass>();
Assert.AreEqual(sut.Speed100, 200);
}
}
Would have expected this to work, but I can see why it's not. But how do I argue, that this is not a problem with AutoFixture, but a problem with the code?
AutoFixture is giving you feedback about the design of your class. The feedback is, you should follow a more object-oriented design for this class.
Protect your private state, to prevent your class from entering an inconsistent state.
You need to make the speed100index field, private, to ensure it remains consistent with the values List.
Here is what I see if I run debugger on your test:
Autofixture assigns a random number to speed100index field because it is public, and in your array there is nothing at point 53 (from my screenshot)
If you set speed100index to be private, Autofixture will not re-assign the number and your test will pass.
Is it possible to change a variable in another scene in unity. I have a script right now that has the user pick 5 heroes and those 5 heroes get saved to a array, but in order for the game to run how i want it, that array will be in another scene and I'm not sure how to go about saving the five heroes data to an array in another scene. I can do it all in one scene but 2 scenes would be more efficient. Here's my code:
using UnityEngine;
using System.Collections;
public class HeroChooser : MonoBehaviour {
public static GameObject Archer;
GameObject Berserker;
GameObject Rouge;
GameObject Warrior;
GameObject Mage;
GameObject MainCamera;
public int counter = 0;
public bool archerOn = false;
public bool berserkerOn = false;
public bool rougeOn = false;
public bool mageOn = false;
public bool warriorOn = false;
// Use this for initialization
void Start () {
}
// Update is called once per frame
void Update () {
}
void OnGUI(){
if(archerOn == false){
if (GUI.Button (new Rect(50,0,50,50), "Archer")){
Archer = GameObject.Find("Archer");
MainCamera = GameObject.Find("Main Camera");
HeroArraySaver heroArraySaver = MainCamera.GetComponent<HeroArraySaver>();
heroArraySaver.array[counter] = Archer;
archerOn = true;
counter++;
}
}
Its saying that: Static member HeroArraySaver.array cannot be accessed with an instance reference, qualify it with a type name instead im not sure how to go about fixing it.
A simple way would be to create an empty GameObject and attach a script/MonoBehaviour to that which holds your data. To make it persist you would have to call DontDestroyOnLoad() on that GameObject. This will ensure your GameObject will hang around when moving to a different scene.
So something like:
GameObject myPersistentDataObject = new GameObject("myPersistentDataObject");
MyDataClass data_class = myPersistentDataObject.AddComponent<MyDataClass>();
//set your data to whatever you need to maintain
And in your Awake of your MyDataClass you'd do something like
void Awake()
{
DontDestroyOnLoad(transform.gameObject);
}
Then in your other scene you can simply find your GameObject again and retrieve its data from the attached component.
Assuming you have integer IDs for the heroes, simply store them in a static variable:
public class GlobalData {
public static int[] heroIds;
}
Static variables can be accessed from any scene and will persist as long as your game runs. The same technique works for strings or enums.
Whats the best way to save variables like userid that is stored and reachable from different pages in WP7.
There's the querystring method, but can be kind of a pain to implement.
When navigating, pass the parameter like a HTTP querystring.
Then, on the otherside, check if the key exists, and extract the value. The downside of this is if you need to do more than 1, you need to type it in yourself, and it only supports strings.
So to pass an integer, you'd need to convert it. (And to pass a complex object, you need to take all the pieces you need to recompile it on the other side)
NavigationService.Navigate(new Uri("/PanoramaPage1.xaml?selected=item2", UriKind.Relative));
protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
{
string selected = String.Empty;
//check to see if the selected parameter was passed.
if (NavigationContext.QueryString.ContainsKey("selected"))
{
//get the selected parameter off the query string from MainPage.
selected = NavigationContext.QueryString["selected"];
}
//did the querystring indicate we should go to item2 instead of item1?
if (selected == "item2")
{
//item2 is the second item, but 0 indexed.
myPanorama.DefaultItem = myPanorama.Items[1];
}
base.OnNavigatedTo(e);
}
Here's a sample app that uses a querystring.
http://dl.dropbox.com/u/129101/Panorama_querystring.zip
A easier (and better) idea is to define a variable globally, or use a static class. In App.xaml.cs, define
using System.Collections.Generic;
public static Dictionary<string,object> PageContext = new Dictionary<string,object>;
Then, on the first page, simply do
MyComplexObject obj;
int four = 4;
...
App.PageContext.Add("mycomplexobj",obj);
App.PageContext.Add("four",four);
Then, on the new page, simply do
MyComplexObj obj = App.PageContext["mycomplexobj"] as MyComplexObj;
int four = (int)App.PageContext["four"];
To be safe, you should probably check if the object exists:
if (App.PageContext.ContainsKey("four"))
int four = (int)App.PageContext["four"];
You may use an App level variable (defined in App.xaml.cs) and access it from anywhere within your app. If you want to persist, shove it into Isolated Storage and read it on App launch/activate. There are helpers available to JSon serialize/deserialize your reads/writes from the Isolated Storage.
Check out Jeff's post (here) on tips to use Isolated Storage.
Hope this helps!
Well "best" is always subjective, however, I think an application service is a good candidate for this sort of thing:-
public interface IPhoneApplicationService : IApplicationService
{
string Name {get; set;}
object Deactivating();
void Activating(object state);
}
public class AuthenticationService : IPhoneApplicationService
{
public static AuthenticationService Current {get; private set; }
public void StartService(ApplicationServiceContext context)
{
Current = this;
}
public void StopService()
{
Current = null;
}
public string Name {get; set;}
public object Deactivating()
{
// Return an serialisable object such as a Dictionary if necessary.
return UserID;
}
public void Activating(object state)
{
UserID = (int)state;
}
public int UserID { get; private set; }
public void Logon(string username, string password)
{
// Code here that eventually assigns to UserID.
}
}
You place an instance of this in your App.xaml:-
<Application.ApplicationLifetimeObjects>
<!--Required object that handles lifetime events for the application-->
<shell:PhoneApplicationService
Launching="Application_Launching" Closing="Application_Closing"
Activated="Application_Activated" Deactivated="Application_Deactivated"/>
<local:AuthenticationService Name="AuthServ" />
</Application.ApplicationLifetimeObjects>
Now you do need to tweak the App.xaml.cs:-
private void Application_Activated(object sender, ActivatedEventArgs e)
{
var state = PhoneApplicationService.Current.State;
foreach (var service in ApplicationLifetimeObjects.OfType<IPhoneApplicationService>())
{
if (state.ContainsKey(service.Name))
{
service.Activating(state[service.Name]);
}
}
}
private void Application_Deactivated(object sender, DeactivatedEventArgs e)
{
var state = PhoneApplicationService.Current.State;
foreach (var service in ApplicationLifetimeObjects.OfType<IPhoneApplicationService>())
{
if (state.ContainsKey(service.Name))
{
state[service.Name] = service.Deactivating();
}
else
{
state.Add(service.Name, service.Deactivating());
}
}
}
You can now access you UserID anywhere in your app with:-
AuthenticationService.Current.UserID
This general pattern can be used to maintain seperation of key application wide services (you don't load a whole bunch of incohesive properties into your App class). It also provides the hooks for maintaining state between activations which is essential.
I have a method Translate extension which searches for a translation. Normally translations are loaded in Window constructor (I tried in App.Setup too). No if i run the application all the translations are displayed correctly, but when opening a user control all translations are gone.
So the question is where do I put my initialization code so it would be executed before VS initializes design window
it should be default constructor
Either the class constructor (or code called from it) or some static member initialized by a static constructor.
Option 1:
public partial class MyUserControl : UserControl
{
int thisWillWork = 1;
int thisWillAlsoWork;
public MyUserControl()
{
thisWillAlsoWork = 1;
InitializeComponents();
}
Option 2:
public class SomeOtherClass
{
public static int YouCanUseThis = 1;
public static int AndThisAlso;
static SomeOtherClass()
{
AndThisAlso = 1;
}
}