Xamarin.Forms MVVM 从 DISplayAlert 得到响应 [英] Xamarin.Forms MVVM getting responce from DIsplayAlert

问题描述

如何从 MVVM 视图正确使用 DisplayAlert()?

How to work with DisplayAlert() correctly from MVVM view?

我有一些屏幕和视图模型.在 ViewModel 中，我定义了一些 Actions:

I have some screen and ViewModel for it. Inside the ViewModel I defined some Actions:

class PageViewModel : INotifyPropertyChanged
{
    public Action DisplayDataSavedPromt;
    public event PropertyChangedEventHandler PropertyChanged = delegate { };

    public ICommand SaveCommand { protected set; get; }

    public PageViewModel()
    {
        SaveCommand = new Command(OnSubmit);
    }

    public void OnSubmit()
    {           
        DisplayDataSavedPromt();
    }

}

然后我从 View Page.cs 调用它:

And then I'm calling it from View Page.cs:

public Page ()
{
    var vm = new PageViewModel();
    this.BindingContext = vm;
    vm.DisplayDataSavedPromt += () => DisplayAlert("Success", "Your data are saved", "OK");
    InitializeComponent ();
}

它工作正常，但我不明白如何将某些操作绑定到此警报的按钮?例如.当用户在 Alert 中点击 OK 时，打开新页面.

And it's working fine, but I can't understand how can I bind some actions to this Alert's buttons? E.g. when user clicks OK inside Alert, open new page.

我应该在 ViewModel 中以某种方式还是在 View 中执行此操作?

Should I do it inside ViewModel somehow or inside View?

推荐答案

你可以在你的视图模型中试试这个

You can try this in your view model

var res = await App.Current.MainPage.DisplayAlert("Success", "Your data are saved", "Ok", "Cancel");

if(res){//logic} else {//logic}

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