將Abp移植進.NET MAUI專案（二）：配置與基類編寫

阿新 • • 發佈：2022-05-25

因為我們要做一個數據持久化型的小應用，所以在完成Abp功能的整合後，我們需要做資料庫相關的配置工作

配置資料庫

在MauiBoilerplate.Core專案中，新增兩個實體類：

我們簡單的寫一個歌曲（song）的實體類

其中包含了歌曲標題（MusicTitle），藝術家（Artist），專輯（Album），時長（Duration）以及發售日期（ReleaseDate）

    public class Song : FullAuditedEntity<long>
    {
        [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public override long Id { get; set; }

        public string MusicTitle { get; set; }

        public string Artist { get; set; }

        public string Album { get; set; }

        public TimeSpan Duration { get; set; }

        public DateTime ReleaseDate { get; set; }

    }

在MauiBoilerplate.EntityFrameworkCore專案中：將這個類新增至MauiBoilerplateDbContext中

public class MauiBoilerplateDbContext : AbpDbContext
{
     //Add DbSet properties for your entities...
     public DbSet<Song> Song { get; set; }
}

新建WithDbContextHelper.cs

建立一個靜態類WithDbContext，利用Abp的工作單元模式對dbcontext執行操作

    public class WithDbContextHelper
    {
        public static void WithDbContext<TDbContext>(IIocResolver iocResolver, Action<TDbContext> contextAction)
    where TDbContext : DbContext
        {
            using (var uowManager = iocResolver.ResolveAsDisposable<IUnitOfWorkManager>())
            {
                using (var uow = uowManager.Object.Begin(TransactionScopeOption.Suppress))
                {
                    var context = uowManager.Object.Current.GetDbContext<TDbContext>();

                    contextAction(context);

                    uow.Complete();
                }
            }
        }

    }

[可選]種子資料相關類編寫

編寫種子資料幫助類SeedHelper.cs，與資料庫初始化類InitialDbBuilder，這裡將在程式啟動時向資料庫插入一些種子資料

    public static class SeedHelper
    {
        public static void SeedHostDb(IIocResolver iocResolver)
        {
            Helper.WithDbContextHelper.WithDbContext<MauiBoilerplateDbContext>(iocResolver, SeedHostDb);
        }

        public static void SeedHostDb(MauiBoilerplateDbContext context)
        {
            context.SuppressAutoSetTenantId = true;

            // Host seed
            new InitialDbBuilder(context).Create();
        }

    }

編寫MauiBoilerplateEntityFrameworkCoreModule.cs

    [DependsOn(
        typeof(MauiBoilerplateCoreModule), 
        typeof(AbpEntityFrameworkCoreModule))]
    public class MauiBoilerplateEntityFrameworkCoreModule : AbpModule
    {
        public bool SkipDbContextRegistration { get; set; }

        public bool SkipDbSeed { get; set; }

        public override void PreInitialize()
        {
            if (!SkipDbContextRegistration)
            {
                Configuration.Modules.AbpEfCore().AddDbContext<MauiBoilerplateDbContext>(options =>
                {
                    if (options.ExistingConnection != null)
                    {
                        DbContextOptionsConfigurer.Configure(options.DbContextOptions, options.ExistingConnection);
                    }
                    else
                    {
                        DbContextOptionsConfigurer.Configure(options.DbContextOptions, options.ConnectionString);
                    }
                });
            }
        }
        public override void Initialize()
        {
 
            IocManager.RegisterAssemblyByConvention(typeof(MauiBoilerplateEntityFrameworkCoreModule).GetAssembly());
            
        }

        public override void PostInitialize()
        {
            Helper.WithDbContextHelper.WithDbContext<MauiBoilerplateDbContext>(IocManager, RunMigrate);
            if (!SkipDbSeed)
            {
                SeedHelper.SeedHostDb(IocManager);
            }
        }

        public static void RunMigrate(MauiBoilerplateDbContext dbContext)
        {
            dbContext.Database.Migrate();
        }


    }

將MauiBoilerplate.EntityFrameworkCore設定為啟動專案，選擇框架為.net6.0

開啟程式包管理器控制檯，選擇預設專案MauiBoilerplate.EntityFrameworkCore

編輯

執行Add-Migration命令，將生成遷移指令碼

執行MauiBoilerplate.EntityFrameworkCore，將生成mato.db等三個檔案，

編輯

編寫基類（可選）

我們在使用相關的父類時，某某ContentPage，或者某某UserControl時，需要像使用AbpServiceBase一樣使用一些常用的功能，比如字串的本地化，配置，AutoMapper物件等，就像AbpServiceBase的註釋裡描述的那樣：

/// <summary>
/// This class can be used as a base class for services.
/// It has some useful objects property-injected and has some basic methods
/// most of services may need to.
/// </summary>

此時，需要編寫一個基類（奈何.net本身沒有Mixin模式，C#語言也不支援多繼承），這些基類僅是注入了一些常用的Manager，方便程式碼編寫者使用，因此基類的建立不是必須的。

比如可以增加一個ContentPageBase類作為ContentPage例項控制元件的基類

新建ContentPageBase.cs檔案，建立類ContentPageBase繼承於ContentPage

    public class ContentPageBase : ContentPage
    {
        public IObjectMapper ObjectMapper { get; set; }


        /// <summary>
        /// Reference to the setting manager.
        /// </summary>
        public ISettingManager SettingManager { get; set; }


        /// <summary>
        /// Reference to the localization manager.
        /// </summary>
        public ILocalizationManager LocalizationManager { get; set; }

        /// <summary>
        /// Gets/sets name of the localization source that is used in this application service.
        /// It must be set in order to use <see cref="L(string)"/> and <see cref="L(string,CultureInfo)"/> methods.
        /// </summary>
        protected string LocalizationSourceName { get; set; }

        /// <summary>
        /// Gets localization source.
        /// It's valid if <see cref="LocalizationSourceName"/> is set.
        /// </summary>
        protected ILocalizationSource LocalizationSource
        {
            get
            {
                if (LocalizationSourceName == null)
                {
                    throw new AbpException("Must set LocalizationSourceName before, in order to get LocalizationSource");
                }

                if (_localizationSource == null || _localizationSource.Name != LocalizationSourceName)
                {
                    _localizationSource = LocalizationManager.GetSource(LocalizationSourceName);
                }

                return _localizationSource;
            }
        }
        private ILocalizationSource _localizationSource;


        /// <summary>
        /// Constructor.
        /// </summary>
        protected ContentPageBase()
        {
            LocalizationSourceName = MauiBoilerplateConsts.LocalizationSourceName;
            ObjectMapper = NullObjectMapper.Instance;
            LocalizationManager = NullLocalizationManager.Instance;
        }

        /// <summary>
        /// Gets localized string for given key name and current language.
        /// </summary>
        /// <param name="name">Key name</param>
        /// <returns>Localized string</returns>
        protected virtual string L(string name)
        {
            return LocalizationSource.GetString(name);
        }

        /// <summary>
        /// Gets localized string for given key name and current language with formatting strings.
        /// </summary>
        /// <param name="name">Key name</param>
        /// <param name="args">Format arguments</param>
        /// <returns>Localized string</returns>
        protected virtual string L(string name, params object[] args)
        {
            return LocalizationSource.GetString(name, args);
        }

        /// <summary>
        /// Gets localized string for given key name and specified culture information.
        /// </summary>
        /// <param name="name">Key name</param>
        /// <param name="culture">culture information</param>
        /// <returns>Localized string</returns>
        protected virtual string L(string name, CultureInfo culture)
        {
            return LocalizationSource.GetString(name, culture);
        }

        /// <summary>
        /// Gets localized string for given key name and current language with formatting strings.
        /// </summary>
        /// <param name="name">Key name</param>
        /// <param name="culture">culture information</param>
        /// <param name="args">Format arguments</param>
        /// <returns>Localized string</returns>
        protected virtual string L(string name, CultureInfo culture, params object[] args)
        {
            return LocalizationSource.GetString(name, culture, args);
        }
    }

同理，若我們使用了其他控制元件類時，可以增加一個Base類作為例項控制元件的基類的

比如Popup控制元件，就編寫一個PopupBase基類。

在這裡我們編寫了兩個基類

編輯

本地化配置

新建一個TranslateExtension.cs作為Xaml標籤的本地化處理類

    [ContentProperty("Text")]
    public class TranslateExtension : DomainService, IMarkupExtension
    {
        public TranslateExtension()
        {
            LocalizationSourceName = MauiBoilerplateConsts.LocalizationSourceName;

        }
        public string Text { get; set; }

        public object ProvideValue(IServiceProvider serviceProvider)
        {
            if (Text == null)
                return "";
            var translation = L(Text);          
            return translation;
        }



    }

在MauiBoilerplateLocalization.cs配置好SourceFiles

    public static void Configure(ILocalizationConfiguration localizationConfiguration)
        {
            localizationConfiguration.Sources.Add(
                new DictionaryBasedLocalizationSource(MauiBoilerplateConsts.LocalizationSourceName,
                    new XmlEmbeddedFileLocalizationDictionaryProvider(
                        typeof(LocalizationConfigurer).GetAssembly(),
                        "MauiBoilerplate.Core.Localization.SourceFiles"
                    )
                )
            );
        }

編寫ViewModelBase

為實現Mvvm設計模式，頁面需要繫結一個繼承於ViewModelBase的型別

在ViewModelBase中，需要實現INotifyPropertyChanged以處理繫結成員變化時候的通知訊息；

ViewModelBase集成於AbpServiceBase以方便ViewModel程式碼編寫者使用常用的功能，比如字串的本地化，配置，AutoMapper物件等。

    public abstract class ViewModelBase : AbpServiceBase, ISingletonDependency, INotifyPropertyChanged
    {
        public ViewModelBase()
        {
            LocalizationSourceName = MauiBoilerplateConsts.LocalizationSourceName;
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected PropertyChangedEventHandler PropertyChangedHandler { get; }

        public void VerifyPropertyName(string propertyName)
        {
            Type type = GetType();
            if (!string.IsNullOrEmpty(propertyName) && type.GetTypeInfo().GetDeclaredProperty(propertyName) == null)
                throw new ArgumentException("找不到屬性", propertyName);
        }

        public virtual void RaisePropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChangedEventHandler propertyChanged = PropertyChanged;
            if (propertyChanged == null)
                return;
            propertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }

        public virtual void RaisePropertyChanged<T>(Expression<Func<T>> propertyExpression)
        {
            if (PropertyChanged == null)
                return;
            string propertyName = GetPropertyName(propertyExpression);
            if (string.IsNullOrEmpty(propertyName))
                return;
            RaisePropertyChanged(propertyName);
        }

        protected static string GetPropertyName<T>(Expression<Func<T>> propertyExpression)
        {
            if (propertyExpression == null)
                throw new ArgumentNullException(nameof(propertyExpression));
            MemberExpression body = propertyExpression.Body as MemberExpression;
            if (body == null)
                throw new ArgumentException("引數不合法", nameof(propertyExpression));
            PropertyInfo member = body.Member as PropertyInfo;
            if (member == null)
                throw new ArgumentException("找不到屬性", nameof(propertyExpression));
            return member.Name;
        }

    }