說明

CommunityToolkit.Mvvm包不提供ioc功能,但是官方建議使用:Microsoft.Extensions.DependencyInjection使用IOC

安裝

nuget：Microsoft.Extensions.DependencyInjection 包

介面和服務的定義實現

public interface IBill
{
    bool IsExistId ( string name );

    string GetData ( string name );
}

public class BillService : IBill
{
    public string GetData ( string name )
    {
        return string.Format( "name:{0}" , name );
    }

    public bool IsExistId ( string name )
    {
        return name == "qq";
    }
}

App.xaml.cs註冊

public partial class App : Application
{
    /// <summary>
    /// Gets the current <see cref="App"/> instance in use
    /// </summary>
    public new static App Current => ( App ) Application.Current;

    /// <summary>
    /// Gets the <see cref="IServiceProvider"/> instance to resolve application services.
    /// </summary>
    public IServiceProvider Services
    {
        get;
    }

    public App ()
    {
        Services = ConfigureServices();

        this.InitializeComponent();
    }

    private static IServiceProvider ConfigureServices ()
    {
        var services = new ServiceCollection();

        //   註冊Services
        services.AddSingleton<IOCDemo.Service.Repository.IBill , IOCDemo.Service.Repository.BillService>();
        services.AddSingleton<IOCDemo.Service.Service.IBill , IOCDemo.Service.Service.BillService>();
        //services.AddSingleton<ISettingsService , SettingsService>();


        //  註冊Viewmodels
        // 不是每個Viewmodels都得來AddTransient,如果Viewmodels不需要ioc,可以不用這裡註冊
        services.AddTransient<IOCDemo.ViewModels.WindowViewModel1>();

        return services.BuildServiceProvider();
    }
}

view中使用

原有的view與viewmodel的綁定方式改變如下：

public partial class Window1 : Window
{
    public Window1 ()
    {
        InitializeComponent();

        // this.DataContext = new WindowViewModel1(); 這樣不可以使用了,請用App.Current.Services.GetService
        this.DataContext = App.Current.Services.GetService<WindowViewModel1>();  

        //代碼任何處,都可以使用App.Current.Services.GetService獲取到服務
        //IFilesService filesService = App.Current.Services.GetService<IFilesService>();
    }
}

viewmodel中使用

vm的構造函數中註入服務即可

readonly Service.Service.IBill _IBill;

public WindowViewModel1 ( Service.Service.IBill iBill )
{
    this._IBill = iBill;
}

[RelayCommand( CanExecute = nameof( CanButton ) )]
void ButtonClick ()
{
    //點擊按鈕,修改標題

    if ( this._IBill.IsExistId( Title ) )
    {
        Title = "qq" + this._IBill.GetData( Title );
    }
    else
    {
        Title = "qq";
    }
}

代碼中獲取服務的方式

this.DataContext = App.Current.Services.GetService<WindowViewModel1>();

//代碼任何處,都可以使用App.Current.Services.GetService獲取到服務
IFilesService filesService = App.Current.Services.GetService<IFilesService>();

自我Demo地址:

https://github.com/aierong/WpfDemo/tree/main/WpfDemoNet6/IOCDemo

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