我想处理来自另一个页面的 clickbutton 事件

Question

我有两个页面 MainPage 和 PlayPage。在 MainPage 内部我有一个框架和一个文本块，在框架内我有 Playpage。当我从播放页面单击按钮时，我更改了一个变量，但文本块没有更新。我怎么做？ 这是我的代码：

public class Swag 
{
    public static int swag = 0;

     public void Add(int a)
    {
         swag += a;
    }

    public void Reduce(int a)
    {
         swag -= a;
    }

    public int Get()
    {
        return swag;
    } 

}

public sealed partial class MainPage : Page
{

    public MainPage()
    {
        this.InitializeComponent();
        MyFrame.Navigate(typeof(PlayPage));
        SwagMeasurer.Text = Convert.ToString(Swag.Get());
    }
}


    public sealed partial class PlayPage : Page
    {
        public PlayPage()
        {
            this.InitializeComponent();
        }

        private void Clicker_Click(object sender, RoutedEventArgs e)
        {
            Swag.swag += 1;
        }

    }

Answer 1

Handling and Raising Events 应该是你的新朋友！

赃物：

public class Swag
{
    private static int _swag;

    public static void Add(int a)
    {
        _swag += a;

        OnUpdate?.Invoke(new SwagEventArgs(a));
        OnAddition?.Invoke(new SwagEventArgs(a));
    }

    public static void Reduce(int a)
    {
        _swag -= a;

        OnUpdate?.Invoke(new SwagEventArgs(a));
        OnSubtraction?.Invoke(new SwagEventArgs(a));
    }

    public static int Get()
    {
        return _swag;
    }

    public static event AddedValueEventHandler OnAddition;
    public static event SubtractedValueEventHandler OnSubtraction;
    public static event UpdatedValueEventHandler OnUpdate;

    public delegate void AddedValueEventHandler(SwagEventArgs e);
    public delegate void SubtractedValueEventHandler(SwagEventArgs e);
    public delegate void UpdatedValueEventHandler(SwagEventArgs e);
}

请记住，privacy should be respected!

---

播放页面：

public partial class PlayPage : Page
{
    public PlayPage()
    {
        InitializeComponent();
    }

    private void Clicker_Sub_Click(object sender, RoutedEventArgs e)
    {
        Swag.Reduce(1);
    }

    private void Clicker_Add_Click(object sender, RoutedEventArgs e)
    {
        Swag.Add(1);
    }
}

请注意，我添加了一个减法Button。

---

主窗口：

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        MyFrame.Navigate(new PlayPage());
        SwagMeasurer.Text = Convert.ToString(Swag.Get());

        Swag.OnAddition += Swag_Addition;
        Swag.OnSubtraction += Swag_OnSubtraction;
        Swag.OnUpdate += Swag_OnUpdate;
    }

    private void Swag_OnUpdate(SwagEventArgs e)
    {
        SwagMeasurer.Text = Convert.ToString(Swag.Get());
    }

    private void Swag_OnSubtraction(SwagEventArgs e)
    {
        LastMode.Text = "That's a negative";
    }

    private void Swag_Addition(SwagEventArgs e)
    {
        LastMode.Text = "That's a positive";
    }
}

LastMode 也是TextBlock（表示用户降低或提高了他的技能级别）。

---

SwagEventArgs：

public class SwagEventArgs : EventArgs
{
    public SwagEventArgs(int value)
    {
        Value = value;
    }

    public readonly int Value;
}

SwagEventArgs 将用于将信息存储为event data。