prism导航功能

延续上一节代码继续

代码结构如下：

1.建立ViewAViewModel类

using Prism.Mvvm;
using Prism.Regions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;

namespace ModuleA.ViewModels
{
    public class ViewAViewModel : BindableBase, IConfirmNavigationRequest  //INavigationAware  //IConfirmNavigationRequest导航离开的时候，进行判断提示
    {
        private string title;

        public string Title
        {
            get { return title; }
            set { title = value; RaisePropertyChanged(); }
        }

        public ViewAViewModel()
        {
            //执行顺序1
        }
        public bool IsNavigationTarget(NavigationContext navigationContext)
        {
            //每次重新重新导航的时候，是否重用原来的实例
            return true;
        }


        public void OnNavigatedFrom(NavigationContext navigationContext)
        {
            //在导航离开时调用。
        }

        /// <summary>
        /// 当已导航到实现时调用。
        /// </summary>
        /// <param name="navigationContext"></param>
        public void OnNavigatedTo(NavigationContext navigationContext)
        {

            //执行顺序2
            if (navigationContext.Parameters.ContainsKey("Title"))//判断是否有值再赋值
            {
                Title = navigationContext.Parameters.GetValue<string>("Title");
            }
        }

        public void ConfirmNavigationRequest(NavigationContext navigationContext, Action<bool> continuationCallback)
        {
            //导航离开的时候，进行判断提示，是否允许从A到B模块

            bool b = true;
            if (MessageBox.Show("确定切换吗", "提示", MessageBoxButton.YesNo) == MessageBoxResult.No)
                b = false;
            continuationCallback(b);
        }
    }
}

2.ViewA.xaml中进行绑定

3.ModuleAfile类中进行匹配

using ModuleA.ViewModels;
using ModuleA.Views;
using Prism.Ioc;
using Prism.Modularity;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ModuleA
{
    public class ModuleAfile : IModule

    {
        public void OnInitialized(IContainerProvider containerProvider)
        {
            //初始化
        }

        public void RegisterTypes(IContainerRegistry containerRegistry)
        {
            //依赖注入，模块注册。和主程序继承PrismApplication类似。
            containerRegistry.RegisterForNavigation<ViewA,ViewAViewModel>();//进行匹配，这里一般不使用自动匹配
        }
    }
}

4.MainViewModel类

using Prism.Commands;
using Prism.Mvvm;
using Prism.Regions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WPFPrism.Views;

namespace WPFPrism.ViewModels
{
    public class MainViewModel : BindableBase
    {
        private readonly IRegionManager regionManager;//区域管理
        private IRegionNavigationJournal journal;//区域导航日志
        public DelegateCommand<string> OpenCommand { get; set; }//创建命令，string用来接收参数，例如ViewA
        public DelegateCommand BackCommand { get; set; }//创建导航上一步命令
        public DelegateCommand ForwardCommand { get; set; }//创建导航下一步命令
        public MainViewModel(IRegionManager regionManager)//这里点击快速操作。拿界面定义的区域Content
        {
            BackCommand = new DelegateCommand(Back);
            ForwardCommand = new DelegateCommand(Forward);
            OpenCommand = new DelegateCommand<string>(Open);
            this.regionManager = regionManager;//拿到这个值
        }

        private void Forward()
        {
            if (journal.CanGoForward)
                journal.GoForward();
        }

        private void Back()//返回上一步方法
        {
            if (journal.CanGoBack)
                journal.GoBack();

        }

        private void Open(string obj)
        {
            NavigationParameters keys = new NavigationParameters();
            keys.Add("Title", "Hello");
            regionManager.Regions["Content"].RequestNavigate(obj, callBack =>
             {
                 if ((bool)callBack.Result)//导航问题
                 {
                     journal = callBack.Context.NavigationService.Journal;
                 }
             }, keys);//这里需要依赖注入的方式
        }
    }

}

5.主界面进行绑定

 

6.App.xaml.cs中不需要变化，只是修改成代码加载的方式

using ModuleA;
using ModuleB;
using Prism.DryIoc;
using Prism.Ioc;
using Prism.Modularity;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;
using WPFPrism.Views;

namespace WPFPrism
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : PrismApplication
    {
        protected override Window CreateShell()
        {
            //通过容器去拿MainView,也是启动的地方
            return Container.Resolve<MainView>();
        }

        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
            //依赖注入的功能，增加依赖注入要实现的内容
            //containerRegistry.RegisterForNavigation<ViewA>(); //containerRegistry.RegisterForNavigation<ViewA>("ViewA的具体名字")自定义，可以这样写;
            //containerRegistry.RegisterForNavigation<ViewB>();
            containerRegistry.RegisterForNavigation<ViewC>();//我们依然使用C模块，C模块是当前程序的。
        }

        protected override void ConfigureModuleCatalog(IModuleCatalog moduleCatalog)
        {
            //这里是走代码的
            moduleCatalog.AddModule<ModuleAfile>();//加载A模块
            moduleCatalog.AddModule<ModuleBfile>();//加载B模块
            base.ConfigureModuleCatalog(moduleCatalog);
        }
        protected override IModuleCatalog CreateModuleCatalog()
        {
            //这里是走配置的
            //return new DirectoryModuleCatalog()
            //{
            //    ModulePath = @"Modules"//这里是主程序exe同文件夹下面的Modules文件夹
            //};
            return base.CreateModuleCatalog();
        }

    }
}

7.效果