[英]How to access a variable declared in a page to a inner class?
我想訪問在同一頁面中創建的新類中在Main class中聲明為public的變量。 我已經做了如下。 但是無法訪問該類中的變量
public sealed partial class MainPage : Page
{
public bool is_arrived = false;
public MainPage()
{
this.InitializeComponent();
bool is_arrived=true;
CallingWebServices asyn_task = new CallingWebServices();
}
public class CallingWebServices
{
//want to access variable "is_arrived" here.
}
}
在這種情況下,應使用構造函數注入,並將is_arrived的值傳遞給CallingWebServices。
public sealed partial class MainPage : Page
{
public bool is_arrived = false;
public MainPage()
{
this.InitializeComponent();
bool is_arrived=true;
CallingWebServices asyn_task = new CallingWebServices(is_arrived);
}
public class CallingWebServices
{
private bool _isArrived;
public CallingWebServices(bool isArrived)
{
_isArrived=isArrived;
}
//want to access variable "is_arrived" here.
}
}
這種方法的一個問題是,如果在父類中更改了is_arrived值,它將失去同步。 因此,另一種方法是將父類的引用傳遞給內部類。
public sealed partial class MainPage : Page
{
public bool is_arrived = false;
public MainPage()
{
this.InitializeComponent();
bool is_arrived=true;
CallingWebServices asyn_task = new CallingWebServices(this);
}
public class CallingWebServices
{
private MainPage _Instance;
public CallingWebServices(MainPage instance)
{
_Instance=instance;
}
//Access variable "instance.is_arrived" here.
}
}
但是,不應鼓勵這種做法,並應采用更好的設計方法來消除這種做法。
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