IDialogAware 对话框

<Grid Background="White">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"></RowDefinition>
            <RowDefinition></RowDefinition>
            <RowDefinition Height="Auto"></RowDefinition>
        </Grid.RowDefinitions>
        <TextBlock DockPanel.Dock="Top" Text="编辑窗口" FontSize="50"/>
        <TextBox Grid.Row="1" Height="30" Text="{Binding Title}"/>
        <StackPanel Grid.Row="2" HorizontalAlignment="Right" Orientation="Horizontal"  >
            <Button Command="{Binding SaveCommand}" Content="确定" Height="30" Width="80"/>
            <Button Command="{Binding CancelCommand}" Margin="10" Content="取消" Height="30" Width="80"/>
        </StackPanel>
    </Grid>

using Prism.Commands;
using Prism.Mvvm;
using Prism.Services.Dialogs;
using System;

namespace PrismWpfBlankApp.ViewModels
{
    public class MsgViewModel : BindableBase, IDialogAware
    {//IDialogAware 对话框接口
        public MsgViewModel()
        {
            SaveCommand = new DelegateCommand(Save);
            CancelCommand = new DelegateCommand(Cancel);
        }
        private string title;
        public string Title
        {
            get { return title; }
            set { SetProperty(ref title, value); }
        }
        public DelegateCommand SaveCommand { get; }
        public DelegateCommand CancelCommand { get; }
        private void Save()
        {
            //当关闭对话框时，回传参数
            DialogParameters param = new DialogParameters();
            param.Add("Value", Title);
            RequestClose?.Invoke(new DialogResult(ButtonResult.OK, param));
        }
        private void Cancel()
        {
            RequestClose?.Invoke(new DialogResult(ButtonResult.No));
        }
        #region 接口
        public event Action<IDialogResult> RequestClose;

        public bool CanCloseDialog()
        {//是否允许关闭窗口
            return true;
        }

        public void OnDialogClosed()
        {//窗口关闭之后的处理业务

        }

        public void OnDialogOpened(IDialogParameters parameters)
        {//打开窗口之前
            Title = parameters.GetValue<string>("Value");//获取传入的参数
        }
        #endregion 
    }
}

  protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
         
            //注册对话框视图
            containerRegistry.RegisterDialog<MsgView, MsgViewModel>();
        }

 public class MainWindowViewModel : BindableBase
    {
       private readonly IDialogService m_DialogService;
    
        private string _title = "Prism Application";
        public string Title
        {
            get { return _title; }
            set { SetProperty(ref _title, value); }
        }

        public MainWindowViewModel(IDialogService dialogService)
        {
            OpenACommand = new DelegateCommand(OpenA);
            m_DialogService = dialogService;
        }
      
        public DelegateCommand OpenACommand { get; }
   
        private void OpenA()
        {
            DialogParameters param=new DialogParameters();
            param.Add("Value", "传入的参数");
            m_DialogService.ShowDialog(nameof(MsgView), param, result =>
            {
                if(result.Result== ButtonResult.OK)
                {
                    //得到返回参数的结果
                    Title = result.Parameters.GetValue<string>("Value");

                }
            });
        }
       
      
    }