XAF 23.1.6 EF Core项目SQL Server会话未关闭及超时问题排查

我正在排查XAF 23.1.6 + EF Core 7.0.3项目中SQL Server存在大量未关闭会话的问题，通过SSMS执行以下查询查看开放会话：

SELECT *
FROM sys.dm_exec_sessions
WHERE session_id > 50 AND host_name = 'MYCOMPUTER'
ORDER BY last_request_end_time ASC

通过向导创建带标准安全的新项目，在Visual Studio中运行并监控SSMS会话，发现操作程序时会话数量只增不减——比如打开用户视图和角色视图后会话增加，但关闭视图后会话并未减少，最终导致用户体验出现超时错误。

更新记录 #

• DbContext代码：

using DevExpress.ExpressApp.Design;
using DevExpress.ExpressApp.EFCore.DesignTime;
using DevExpress.Persistent.BaseImpl.EF;
using DevExpress.Persistent.BaseImpl.EF.PermissionPolicy;
using Microsoft.EntityFrameworkCore;

namespace MyApp.Module.BusinessObjects;

public class MyAppContextInitializer : DbContextTypesInfoInitializerBase
{
    protected override DbContext CreateDbContext()
    {
        var optionsBuilder = new DbContextOptionsBuilder<MyAppEFCoreDbContext>()
            .UseSqlServer(";")
            .UseChangeTrackingProxies()
            .UseObjectSpaceLinkProxies();
        return new MyAppEFCoreDbContext(optionsBuilder.Options);
    }
}

[TypesInfoInitializer(typeof(MyAppContextInitializer))]
public class MyAppEFCoreDbContext : DbContext
{
    public MyAppEFCoreDbContext(DbContextOptions<MyAppEFCoreDbContext> options) : base(options)
    {
    }
    
    public DbSet<ModelDifference> ModelDifferences { get; set; }
    public DbSet<ModelDifferenceAspect> ModelDifferenceAspects { get; set; }
    public DbSet<PermissionPolicyRole> Roles { get; set; }
    public DbSet<MyApp.Module.BusinessObjects.ApplicationUser> Users { get; set; }
    public DbSet<MyApp.Module.BusinessObjects.ApplicationUserLoginInfo> UserLoginInfos { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.HasChangeTrackingStrategy(ChangeTrackingStrategy.ChangingAndChangedNotificationsWithOriginalValues);
        modelBuilder.UsePropertyAccessMode(PropertyAccessMode.PreferFieldDuringConstruction);
        modelBuilder.Entity<MyApp.Module.BusinessObjects.ApplicationUserLoginInfo>(
            b =>
            {
                b.HasIndex(
                    nameof(DevExpress.ExpressApp.Security.ISecurityUserLoginInfo.LoginProviderName),
                    nameof(DevExpress.ExpressApp.Security.ISecurityUserLoginInfo.ProviderUserKey))
                    .IsUnique();
            });
        modelBuilder.Entity<ModelDifference>()
            .HasMany(t => t.Aspects)
            .WithOne(t => t.Owner)
            .OnDelete(DeleteBehavior.Cascade);
    }
}

• 演示项目：已准备演示项目并上传至代码仓库。
• 问题重现：在简单控制台项目中重现了问题：打开DbContext添加记录后关闭，会话直到程序退出才关闭。
• 问题根源定位：通过相关技术资料得知，此前通过开放会话数排查超时错误的方向有误，最终发现部分自定义代码存在问题：

public static void StartPurchaseOrderDetailView(XafApplication application, ActionBaseEventArgs e)
{
    var os = application.CreateObjectSpace(typeof(PurchaseOrder));
    var h = os.CreateObject<PurchaseOrder>();
    var detailView = application.CreateDetailView(os, h);
    // 以下代码缺失
    detailView.Closed += (sender, args) => ((DetailView)sender).ObjectSpace.Dispose();
    e.ShowViewParameters.CreatedView = detailView;
    e.ShowViewParameters.NewWindowTarget = NewWindowTarget.MdiChild;
    e.ShowViewParameters.TargetWindow = TargetWindow.NewWindow;
}

上述代码中缺失了detailView.Closed事件绑定的Dispose逻辑，导致ObjectSpace未被及时释放，进而引发数据库会话无法关闭。后续将验证该修复方案是否生效。

内容的提问来源于stack exchange，提问作者Kirsten