Prism 三依赖注入

1、容器的支持情况。

由于Prism.DryIoc支持的平台更多，可以退从NuGet中直接引入，所以我们选择使用Prism.DryIoc做依赖注入。需要注意的是虽然 DryIoc 和 Unity Container 在 NuGet.org 上可用，但它们仍受 Prism 许可证的约束。您应该拥有有效的 Prism 许可证。

2、服务的注册。注册可以注册临时服务和注册单例服务。

2.1、新建ServiceBLL文件夹，新建接口IPrintService.cs（我搞饭了，这个接口应该创建在ServiceCore文件夹下），代码如下

cs 复制代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WpfApp1.ServiceBLL
{
    public interface IPrintService
    {
        public void Print();
    }
}

2.2、新建ServiceCore文件夹，新建接口PrintService.cs（我搞饭了，这个接口应该创建在ServiceBLL文件夹下），代码如下

cs 复制代码

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WpfApp1.ServiceBLL
{
    public class PrintService:IPrintService
    {
        public string PrintContent { get; set; } = "未设置内容";
        public void Print()
        {            
            Debug.WriteLine(PrintContent);
        }
    }
}

2.3、新建ViewModels文件夹，创建MainWindowViewModel.cs代码如下。

cs 复制代码

using Prism.Ioc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WpfApp1.ServiceBLL;

namespace WpfApp1.ViewModels
{
    public class MainWindowViewModel
    {
        private readonly IContainerProvider _containerProvider;
        public MainWindowViewModel(IContainerProvider containerProvider)
        {
            _containerProvider = containerProvider;
            PrintService _PrintService = _containerProvider.Resolve<PrintService>();
            _PrintService.PrintContent = "已设置内容";
            _PrintService.Print();
        }


        private DelegateCommand _PrintCommand;

        public DelegateCommand PrintCommand
        {
            get
            {
                return _PrintCommand ?? (_PrintCommand = new DelegateCommand(Print));
            }
        }


        private void Print()
        {
            _containerProvider.Resolve<PrintService>().Print();
        }
    }
}

2.4、创建Views文件夹，将MainWindow.xaml文件移动到Views文件夹中，代码如下。

XML 复制代码

<Window x:Class="WpfApp1.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:local="clr-namespace:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <StackPanel>
        <TextBox x:Name="tbText" Width="200" Height="30" HorizontalAlignment="Center" Text="设置内容"/>
        <Button Width="200" Height="30" Content="点击" Command="{Binding PrintCommand}"/>
    </StackPanel>
</Window>

2.5、App.xaml.cs文件代码如下。

cs 复制代码

using Prism.Ioc;
using System.Configuration;
using System.Data;
using System.Printing;
using System.Windows;
using WpfApp1.ServiceBLL;
using WpfApp1.Views;

namespace WpfApp1
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : PrismApplication
    {
        protected override Window CreateShell()
        {
            return Container.Resolve<MainWindow>();
        }

        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
            //containerRegistry.Register<PrintService>();
            //containerRegistry.Register<IPrintService,PrintService>();
            containerRegistry.RegisterInstance<PrintService>(new PrintService());
        }
    }

}

注册临时服务可以这样使用，containerRegistry.Register<PrintService>();和

containerRegistry.Register<IPrintService,PrintService>();

注册单例服务可以这样使用，containerRegistry.RegisterInstance<PrintService>(new PrintService());

2.6、检查服务是否已注册，可以通过以下方检擦，代码如下。

cs 复制代码

            if (_containerProvider.IsRegistered<PrintService>())
            {
                _containerProvider.Resolve<PrintService>().Print();
            }

2.6、延迟加载服务Lazy<IFoo>方式注册服务，MainWindowViewModel.cs代码如下。

cs 复制代码

using Prism.Ioc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WpfApp1.ServiceBLL;

namespace WpfApp1.ViewModels
{
    public class MainWindowViewModel
    {
        private readonly IContainerProvider _containerProvider;
        private readonly PrintService _printService;
        public MainWindowViewModel(IContainerProvider containerProvider, Lazy<PrintService> printService)
        {
            _containerProvider = containerProvider;
            _printService = printService.Value;
            _printService.PrintContent = "已设置内容";
        }

        private DelegateCommand _PrintCommand;

        public DelegateCommand PrintCommand
        {
            get
            {
                return _PrintCommand ?? (_PrintCommand = new DelegateCommand(Print));
            }
        }


        private void Print()
        {
            _printService.Print();
        }
    }
}

Func<PrintService> printService 方式注册服务，MainWindowViewModel.cs代码如下。

cs 复制代码

using Prism.Ioc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using WpfApp1.ServiceBLL;

namespace WpfApp1.ViewModels
{
    public class MainWindowViewModel
    {
        private readonly IContainerProvider _containerProvider;
        private readonly PrintService _printService;
        public MainWindowViewModel(IContainerProvider containerProvider, Func<PrintService> printService)
        {
            _containerProvider = containerProvider;
            _printService = printService.Invoke();
            _printService.PrintContent = "已设置内容";
        }

        private DelegateCommand _PrintCommand;

        public DelegateCommand PrintCommand
        {
            get
            {
                return _PrintCommand ?? (_PrintCommand = new DelegateCommand(Print));
            }
        }


        private void Print()
        {
            _printService.Print();
        }
    }
}