Original: the .NET WPF MVVM framework Prism Core 3 Series data binding

A. Installation Prism

1. Use Package Manager Console #

Install-Package Prism.Unity -Version 7.2.0.1367

You can also remove the '-Version 7.2.0.1367' to obtain the latest version

2. Use the package management solutions Nuget #

In the above perhaps we have a question? Why install prism will have relations with Prism.Unity, we know that Unity is a IOC container, and Prism itself IOC support, and currently supports several official IOC container:

1. Microsoft and unity because it is official, and supports component-based prism, thus I recommend using prism.unity, prism7 does not support prism.Mef in official documents, Prism 7.1 will not support prism.Autofac

2. After installing prism.unity already contains all the prism of the core library, and architecture as follows:

II. Data binding

We create folders and ViewModels Views folder, MainWindow placed Views folder, then create the following folder in ViewModels MainWindowViewModel categories, as follows:

xmal code is as follows:

<Window x:Class="PrismSample.Views.MainWindow"
        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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:prism="http://prismlibrary.com/"
        xmlns:local="clr-namespace:PrismSample"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800" prism:ViewModelLocator.AutoWireViewModel="True">
    <StackPanel>
        <TextBox Text="{Binding Text}" Margin="10" Height="100" FontSize="50" Foreground="Black" BorderBrush="Black"/>
        <Button  Height="100" Width="300" Content="Click Me" FontSize="50" Command="{Binding ClickCommnd}"/>
    </StackPanel>
</Window>

ViewModel代码如下：

using Prism.Commands;
using Prism.Mvvm;

namespace PrismSample.ViewModels
{
   public class MainWindowViewModel:BindableBase
    {
        private string _text;
        public string Text
        {
            get { return _text; }
            set { SetProperty(ref _text, value); }
        }

        private DelegateCommand _clickCommnd;
        public DelegateCommand ClickCommnd =>
            _clickCommnd ?? (_clickCommnd = new DelegateCommand(ExecuteClickCommnd));

        void ExecuteClickCommnd()
        {
            this.Text = "Click Me！";
        }

        public MainWindowViewModel()
        {
            this.Text = "Hello Prism!";
        }
    }
}

启动程序：

点击 click Me 按钮:

可以看到，我们已经成功的用prism实现数据绑定了，且View和ViewModel完美的前后端分离

但是现在我们又引出了另外一个问题,当我们不想按照prism的规定硬要将View和ViewModel放在Views和ViewModels里面，又或许自己的项目取名规则各不相同怎么办，这时候就要用到另外几种方法：

1.更改命名规则#

如果，公司命名规则很变态，导致项目结构变成这样(这种公司辞职了算了)：

首先我们在App需要引入prism，修改‘Application’为‘prism:PrismApplication’且删除StartupUri

xmal代码如下：

<prism:PrismApplication x:Class="PrismSample.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:prism="http://prismlibrary.com/"
             xmlns:local="clr-namespace:PrismSample">
    <Application.Resources>
         
    </Application.Resources>
</prism:PrismApplication>

cs后台代码如下：

using Prism.Unity;
using Prism.Ioc;
using Prism.Mvvm;
using System.Windows;
using PrismSample.Viewsb;
using System;
using System.Reflection;

namespace PrismSample
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : PrismApplication
    {
        //设置启动起始页
        protected override Window CreateShell()
        {
            return Container.Resolve<MainWindow>();
        }

        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {

        }

        //配置规则
        protected override void ConfigureViewModelLocator()
        {
            base.ConfigureViewModelLocator();
            ViewModelLocationProvider.SetDefaultViewTypeToViewModelTypeResolver((viewType) =>
            {
                var viewName = viewType.FullName.Replace(".Viewsb.", ".ViewModelsa.OhMyGod.");
                var viewAssemblyName = viewType.GetTypeInfo().Assembly.FullName;
                var viewModelName = $"{viewName}Test, {viewAssemblyName}";
                return Type.GetType(viewModelName);
            });
        }
    }
}

上面这两句是关键：

".Viewsb." 表示View所在文件夹namespace,".ViewModelsa.OhMyGod." 表示ViewModel所在namespace

1	`var` `viewName = viewType.FullName.Replace(` `".Viewsb."` `,` `".ViewModelsa.OhMyGod."` `);`

Test表示ViewModel后缀

var viewModelName = $"{viewName}Test, {viewAssemblyName}";

2.自定义ViewModel注册#

我们新建一个Foo类作为自定义类，代码如下：

using Prism.Commands;
using Prism.Mvvm;

namespace PrismSample
{
   public class Foo:BindableBase
    {

        private string _text;
        public string Text
        {
            get { return _text; }
            set { SetProperty(ref _text, value); }
        }

        public Foo()
        {
            this.Text = "Foo";
        }

        private DelegateCommand _clickCommnd;
        public DelegateCommand ClickCommnd =>
            _clickCommnd ?? (_clickCommnd = new DelegateCommand(ExecuteClickCommnd));

        void ExecuteClickCommnd()
        {
            this.Text = "Oh My God！";
        }
    }
}

修改App.cs代码:

protected override void ConfigureViewModelLocator()
        {
            base.ConfigureViewModelLocator();
            ViewModelLocationProvider.Register<MainWindow, Foo>();
            //ViewModelLocationProvider.SetDefaultViewTypeToViewModelTypeResolver((viewType) =>
            //{
            //    var viewName = viewType.FullName.Replace(".Viewsb.", ".ViewModelsa.OhMyGod.");
            //    var viewAssemblyName = viewType.GetTypeInfo().Assembly.FullName;
            //    var viewModelName = $"{viewName}Test, {viewAssemblyName}";
            //    return Type.GetType(viewModelName);
            //});
        }

运行：

点击按钮：

就算是不注释修改命名规则的代码，我们发现运行结果还是一样，因此我们可以得出结论，

这种直接的，不通过反射注册的自定义注册方式优先级会高点，在官方文档也说明这种方式效率会高点

且官方提供4种方式，其余三种的注册方式如下：

ViewModelLocationProvider.Register(typeof(MainWindow).ToString(), typeof(MainWindowTest));

ViewModelLocationProvider.Register(typeof(MainWindow).ToString(), () => Container.Resolve<Foo>());

ViewModelLocationProvider.Register<MainWindow>(() => Container.Resolve<Foo>());

.NET Core 3 WPF MVVM data binding framework Prism Series