C# 如何从Xamarin表单中的ViewModel获取数字输入

我需要在命令运行后向用户请求一个号码。这需要在视图模型中运行。我尝试过ACR.UserDialog，但似乎不知道如何从viewmodel调用它

  public MainPage()
        {
           InitializeComponent();

            personsViewModel =  new PersonsViewModel(Navigation, UserDialogs.Instance, this);
            this.BindingContext = personsViewModel;



        }

大概是这样的：

void RemoveItem()
{ 
    int intQuantity = (dialog from user to get the quantity);
}

提前谢谢

演示如何做到这一点

// Dialogs is an IUserDialogs that you pass to your VM from your page
// using UserDialogs.Instance
var result = await Dialogs.PromptAsync(new PromptConfig()

  .SetTitle("Max Length Prompt")
  .SetPlaceholder("Maximum Text Length (10)")
  .SetInputMode(InputType.Name)
  .SetMaxLength(10));

// result.Text will contain the user's response

---

是否希望在viewModel中使用命令获得如下结果

首先，您需要创建

AbstractViewModel

using System.ComponentModel;
using System.Runtime.CompilerServices;
using Acr.UserDialogs;

namespace MyCusListview
{
    public abstract class AbstractViewModel : INotifyPropertyChanged
    {
        protected AbstractViewModel(IUserDialogs dialogs)
        {
            this.Dialogs = dialogs;
        }


        protected IUserDialogs Dialogs { get; }


        protected virtual void Result(string msg)
        {
            this.Dialogs.Alert(msg);
        }


        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

然后实现这个抽象类，不要忘记在viewmodel构造函数中添加

IUserDialogs对话框。然后按下
对话框.PromptAsync
，您可以在
input.Text
中获得结果

  public class PersonsViewModel: AbstractViewModel
    {   
        public ObservableCollection<Person> persons { get; set; }
        public static ObservableCollection<Person> selectItems { get; set; }

        public ICommand TextChangeCommand { protected set; get; }
       

     
        public PersonsViewModel(INavigation navigation, IUserDialogs dialogs, ContentPage page):base(dialogs)
        {

            TextChangeCommand = new Command<Person>(async (key) =>
            {
                var input = await dialogs.PromptAsync("What is your email?", "Confirm Email", "Confirm", "Cancel");

                if (input.Ok)
                {
                    Console.WriteLine("Your email is" + input.Text);
                }

            });
        }
     }


下面是运行结果

不可理解的不完整问题，请修改它以获得更好的答案对不起，我不知道它是如何不完整的。。我只需要能够要求用户从Viewmodel输入一个数字。也许你有一些建议？还是需要澄清的问题？我不知道还能怎么问。谢谢。不过，我不明白从ViewModel输入的数字是什么意思。。与ACR的联系是什么。分步写下你想要达到的目标。