Navigation区域导航

功能实现

这里以实现按钮打开A和打开B为例

首先创建ViewA和ViewB的页面

在App.xaml.cs中实现对页面的注册

 protected override void RegisterTypes(IContainerRegistry containerRegistry)
{containerRegistry.RegisterForNavigation<ViewA>("PageA");containerRegistry.RegisterForNavigation<ViewB>();
}

在MainWindowViewModel中实现对区域内容的设置。以打开A为例，创建按钮，然后实现打开A的函数功能。

using Prism.Commands;
using Prism.Mvvm;
using Prism.Regions;
using System;namespace BlankCoreApp1.ViewModels
{public class MainWindowViewModel : BindableBase{private readonly IRegionManager regionManager;public DelegateCommand OpenACommand { get; private set; }public MainWindowViewModel(IRegionManager regionManager){OpenACommand = new DelegateCommand(OpenA);this.regionManager = regionManager;}private void OpenA(){// 设置区域内容为PageA的内容regionManager.RequestNavigate("ContentRegion", "PageA", param);}}
}

实现参数传递

创建一个ViewAViewModel.cs的类，用来实现对ViewA页面参数的传递

其中可以实现以下接口

using Prism.Mvvm;
using Prism.Regions;
using System;
using System.Collections.Generic;
using System.Text;namespace BlankCoreApp1.ViewModels
{public class ViewAViewModel : BindableBase, INavigationAware{/// <summary>/// 判断是否需要重新创建一个新的实例/// </summary>/// <param name="navigationContext"></param>/// <returns></returns>public bool IsNavigationTarget(NavigationContext navigationContext){return true;}/// <summary>/// 导航离开当前页时触发/// </summary>/// <param name="navigationContext"></param>public void OnNavigatedFrom(NavigationContext navigationContext){}/// <summary>/// 导航完成前接收用户传递的参数以及是否允许导航等控制/// </summary>/// <param name="navigationContext"></param>public void OnNavigatedTo(NavigationContext navigationContext){}}
}

在MainWindowViewModel.cs中的OpenA函数中实现对参数的传递。这里使用NavigationParameters来创建一个param参数，使用键值对的方式把键值添加进去，使用regionManager.RequestNavigate传递参数。

private void OpenA()
{// 传递参数 通过RequestNavigate来把param参数传递过去，通过navigationContext来接收参数的值NavigationParameters param = new NavigationParameters();param.Add("Value", "Hello");// 设置区域内容为PageA的内容regionManager.RequestNavigate("ContentRegion", "PageA", param);//传递参数的另一种写法// regionManager.RequestNavigate("ContentRegion", $"PageA?Value=Hello");
}

然后通过ViewModel中的navigationContext来接收参数的值。

private string title;
public string Title
{get { return title; }set { title = value;RaisePropertyChanged(); }
}public void OnNavigatedTo(NavigationContext navigationContext)
{// 接收键值为Value的值Title = navigationContext.Parameters.GetValue<string>("Value");
}

实现弹窗提醒

使用IConfirmNavigationRequest接口来实现。在ViewAViewModel.cs中继承该类，使用其中的

ConfirmNavigationRequest方法来实现

public void ConfirmNavigationRequest(NavigationContext navigationContext, Action<bool> continuationCallback)
{bool result = true;if(MessageBox.Show("确认导航？","温馨提示",MessageBoxButton.YesNo) == MessageBoxResult.No){result =  false;}continuationCallback(result);
}

导航日志

使用IRegionNavigationJournal来实现导航日志的接口。接口实现了GoForward和GoBack方法。

在OpenA或者OpenB中使用arg调用回调函数来实现日志获取。

using Prism.Commands;
using Prism.Mvvm;
using Prism.Regions;
using System;namespace BlankCoreApp1.ViewModels
{public class MainWindowViewModel : BindableBase{private readonly IRegionManager regionManager;IRegionNavigationJournal journal; // 导航日志的接口public DelegateCommand OpenACommand { get; private set; }public DelegateCommand OpenBCommand { get; private set; }public DelegateCommand GoBackCommand { get; private set; }public DelegateCommand GoForwordCommand { get; private set; }public MainWindowViewModel(IRegionManager regionManager){OpenACommand = new DelegateCommand(OpenA);OpenBCommand = new DelegateCommand(OpenB);GoBackCommand = new DelegateCommand(GoBack);GoForwordCommand = new DelegateCommand(GoForword);this.regionManager = regionManager;}private void GoForword(){journal.GoForward();}private void GoBack(){journal.GoBack();}private void OpenB(){// 设置区域内容为ViewB的内容。 使用回调函数arg来拿到导航日志regionManager.RequestNavigate("ContentRegion", "ViewB", arg =>{journal = arg.Context.NavigationService.Journal;});}private void OpenA(){// 传递参数 通过RequestNavigate来把param参数传递过去，通过navigationContext来接收参数的值NavigationParameters param = new NavigationParameters();param.Add("Value", "Hello");// 设置区域内容为PageA的内容 使用回调函数arg来拿到导航日志regionManager.RequestNavigate("ContentRegion", "PageA",arg=> {journal = arg.Context.NavigationService.Journal;}, param);//传递参数的另一种写法// regionManager.RequestNavigate("ContentRegion", $"PageA?Value=Hello");}}
}