xamarin - 在内容页 XAMARIN 表单中调用 onresumo() 方法

我有以下问题
我在 iOS 中的声明。当用户在后台返回应用程序时，我需要激活命令。在我的 ContentPage 上，我找不到识别返回的方法。在Android中，它可以正常工作，只有在iOS中，我在内容中找不到任何显示我正在返回的功能

 protected override void OnAppearing()
    {
        Debug.WriteLine("OnAppearing()");
        base.OnAppearing();
    }

    protected override void OnDisappearing()
    {
        Debug.WriteLine("OnDisappearing");
        base.OnDisappearing();
    }

    protected override void OnBindingContextChanged()
    {
        Debug.WriteLine("OnBindingContextChanged");
        base.OnBindingContextChanged();
    }

我尝试了三个选项但没有结果

最佳答案

我通常这样做，所以我不必费心订阅:

public partial class App : Application
{
    public App()
    {
        InitializeComponent();

        MainPage = new MainPage();
    }

    protected override async void OnStart()
    {
        if (Application.Current.MainPage is IAppStateAware appStateAwarePage)
            await appStateAwarePage.OnStartApplicationAsync();
        if (Application.Current.MainPage.BindingContext is IAppStateAware appStateAwareVm)
            await appStateAwareVm.OnStartApplicationAsync();
        // Handle when your app starts
    }

    protected override async void OnSleep()
    {
        if (Application.Current.MainPage is IAppStateAware appStateAwarePage)
            await appStateAwarePage.OnSleepApplicationAsync();
        if (Application.Current.MainPage.BindingContext is IAppStateAware appStateAwareVm)
            await appStateAwareVm.OnSleepApplicationAsync();
        // Handle when your app sleeps
    }

    protected override async void OnResume()
    {
        if (Application.Current.MainPage is IAppStateAware appStateAwarePage)
            await appStateAwarePage.OnResumeApplicationAsync();
        if (Application.Current.MainPage.BindingContext is IAppStateAware appStateAwareVm)
            await appStateAwareVm.OnResumeApplicationAsync();
        // Handle when your app resumes
    }
}

public class YourContentPage : Page, IAppStateAware
{
    public Task OnResumeApplicationAsync()
    {
        throw new System.NotImplementedException();
    }

    public Task OnSleepApplicationAsync()
    {
        throw new System.NotImplementedException();
    }

    public Task OnStartApplicationAsync()
    {
        throw new System.NotImplementedException();
    }
}

public interface IAppStateAware
{
    Task OnResumeApplicationAsync();
    Task OnSleepApplicationAsync();
    Task OnStartApplicationAsync();
}

关于xamarin - 在内容页 XAMARIN 表单中调用 onresumo() 方法，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/46201143/