新建Update事件，增加Prism事件列表

新建文件Mytodo/Common/Events/UpdateLoadingEvent.cs

using Prism.Events;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace Mytodo.Common.Events
{public class UpdateModel{public bool IsOpen { get; set; }}public class UpdateLoadingEvent : PubSubEvent<UpdateModel>{}
}

新建含加载窗体基类

新建文件Mytodo/ViewModels/NavigationViewModel.cs

using Prism.Events;
using Prism.Ioc;
using Prism.Regions;
using Mytodo.Common.Events;
using System;
using System.CodeDom;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media.Animation;
using Prism.Mvvm;
using Mytodo.Extensions;namespace Mytodo.ViewModels
{public class NavigationViewModel : BindableBase,INavigationAware{private readonly IContainerProvider container;/// <summary>/// 事件聚合器/// </summary>public readonly IEventAggregator aggregator;public NavigationViewModel(IContainerProvider container){this.container = container;aggregator = container.Resolve<IEventAggregator>();}/// <summary>/// 是否允许导航/// </summary>/// <param name="navigationContext"></param>/// <returns></returns>public bool IsNavigationTarget(NavigationContext navigationContext){return true;}public virtual void OnNavigatedFrom(NavigationContext navigationContext){}public virtual void OnNavigatedTo(NavigationContext navigationContext){}public void UpdateLoding(bool isopen){aggregator.UpdateLoading(new Common.Events.UpdateModel(){IsOpen = isopen});}}
}

建立数据加载窗体扩展方法

新建文件Mytodo/Extensions/DialogExtension.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;
using Prism.Events;
using Mytodo.Common.Events;namespace Mytodo.Extensions
{public static class DialogExtension{/// <summary>/// 推送消息/// </summary>/// <param name="aggregator"></param>/// <param name="model"></param>public static void UpdateLoading(this IEventAggregator aggregator, UpdateModel model){aggregator.GetEvent<UpdateLoadingEvent>().Publish(model);}/// <summary>/// 注册等待的消息/// </summary>/// <param name="aggregator"></param>/// <param name="action"></param>public static void Register(this IEventAggregator aggregator, Action<UpdateModel> action){aggregator.GetEvent<UpdateLoadingEvent>().Subscribe(action);}}
}

主窗口命名

修改文件Mytodo/Extensions/DialogExtension.cs

<Grid><materialDesign:DialogHostx:Name="DialogHost"DialogTheme="Inherit"

主窗口订阅消息

修改文件Mytodo/Views/MainView.xaml.cs

namespace Mytodo.Views
{/// <summary>/// MainView.xaml 的交互逻辑/// </summary>public partial class MainView : Window{/// <summary>/// 订阅消息/// </summary>public MainView(IEventAggregator aggregator){aggregator.Register(arg =>{DialogHost.IsOpen = arg.IsOpen;if (DialogHost.IsOpen)DialogHost.DialogContent = new ProgressView();});

新建数据加载窗体ProgressView

修改文件Mytodo/Views/ProgressView.xaml

<UserControlx:Class="Mytodo.Views.ProgressView"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:local="clr-namespace:Mytodo.Views"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"d:DesignHeight="450"d:DesignWidth="800"mc:Ignorable="d"><StackPanel Background="Transparent"><ProgressBarWidth="50"Height="50"Background="Transparent"IsIndeterminate="True"Style="{StaticResource MaterialDesignCircularProgressBar}" /></StackPanel>
</UserControl>

修改viewmodel ，使用数据加载窗体

修改文件Mytodo/Views/TodoViewModel.cs

修改为：

using Mytodo.Common.Models;
using Mytodo.Service;
using Prism.Commands;
using Prism.Ioc;
using Prism.Mvvm;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using MyToDo.Share.Models;
using System.Threading.Tasks;
using Prism.Regions;namespace Mytodo.ViewModels
{public class TodoViewModel: NavigationViewModel{private readonly ITodoService service;private ObservableCollection<ToDoDto>? todoDtos;private bool isRightOpen;public bool IsRightOpen{get { return isRightOpen; }set { isRightOpen = value; RaisePropertyChanged(); }}public DelegateCommand OpenRightContentCmd { set; get; }/// <summary>/// todo集合/// </summary>public ObservableCollection<ToDoDto>? TodoDtos{get { return todoDtos; }set { todoDtos = value; RaisePropertyChanged(); }}public TodoViewModel(ITodoService service,IContainerProvider provider) : base(provider){TodoDtos=new ObservableCollection<ToDoDto>();OpenRightContentCmd = new DelegateCommand(Add);this.service = service;}/// <summary>/// 获取所有数据/// </summary>async void GetDataAsync(){//调用数据加载页面UpdateLoding(true);var todoResult = await service.GetAllAsync(new MyToDo.Share.Parameters.QueryParameter { PageIndex = 0, PageSize = 100 });if (todoResult.Status){todoDtos.Clear();foreach(var item in todoResult.Result.Items)todoDtos.Add(item);}//卸载数据加载页面UpdateLoding(false);}/// <summary>/// 打开待办事项弹窗/// </summary>void Add(){IsRightOpen = true;}public override void OnNavigatedTo(NavigationContext navigationContext){base.OnNavigatedTo(navigationContext);GetDataAsync();}}
}