.NET Core 3 WPF MVVM框架 Prism系列之数据绑定

 一.安装Prism

 

1.使用程序包管理控制台

Install-Package Prism.Unity -Version 7.2.0.1367
也可以去掉‘-Version 7.2.0.1367’获取最新的版本

 2.使用管理解决方案的Nuget包

 


在上面或许我们有个疑问?为啥安装prism会跟Prism.Unity有关系,我们知道Unity是个IOC容器,而Prism本身就支持IOC,且目前官方支持几种IOC容器:

1.且unity由于是微软官方的,且支持prism的组件化,由此我推荐使用prism.unity,在官方文档中prism7不支持prism.Mef,Prism 7.1将不支持prism.Autofac
2.安装完prism.unity就已经包含着所有prism的核心库了,架构如下:

二.实现数据绑定

我们先创建Views文件夹和ViewModels文件夹,将MainWindow放在Views文件夹下,再在ViewModels文件夹下面创建MainWindowViewModel类,如下:

 

xmal代码如下:
<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
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框架 Prism系列之数据绑定

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