如何使用多个主键表动态创建 DevExpress XPO？

问题描述

我在本主题中尝试示例 https://github.com/DevExpress-Examples/XPO_how-to-create-an-xpclassinfo-descendant-to-dynamically-build-a-persistent-class-structure-e1729

但它只适用于单个主键表。所以我搜索了更多发现这个： https://github.com/DevExpress-Examples/XPO_how-to-create-persistent-classes-mapped-to-tables-with-a-composite-primary-key-at-runtime-e4606

但是有很大的不同，我认为它不满足，因为它谈到了复合键（一个键有很多列）所以我只需要一个从 sql -Server 表动态创建 XPO 的例子：我的表架构如下

XPOCollectionSource 然后在服务器模式下绑定到网格……这就是我所需要的。

我使用的代码

XPServerCollectionSource GetServerModeSourceForTable(IDbConnection connection,string tableName) {  
    XPDictionary dict = new ReflectionDictionary();  
    xpclassInfo classInfo = dict.CreateClass(dict.QueryClassInfo(typeof(LiteDataObject)),tableName);  
    DBTable[] tables = ((ConnectionProvidersql)Xpodefault.GetConnectionProvider(connection,autocreateOption.None)).GetStorageTables(tableName);  
    foreach (DBColumn col in tables[0].Columns) {  
        XPMemberInfo member = classInfo.CreateMember(col.Name,DBColumn.GetType(  
            col.ColumnType));  
        if (tables[0].PrimaryKey.Columns.Contains(col.Name))  
            member.AddAttribute(new KeyAttribute());  
    }  
    return new XPServerCollectionSource(new Session(Xpodefault.GetDataLayer(  
        connection,dict,autocreateOption.None)),classInfo);  
}

一目了然。如何将 XPServerCollectionSource 与动态创建的 XPO 对象一起使用。有两个主键。

解决方法

https://github.com/DevExpress-Examples/XPO_how-to-create-persistent-classes-mapped-to-tables-with-a-composite-primary-key-at-runtime-e4606/blob/19.2.7%2B/CS/XpoConsoleApplication/XPComplexCustomMemberInfo.cs

这是一个必须使用的类。谁需要更多细节。我可以免费帮助他。

实现可以是这样的：

[NonPersistent]
public class XPDynamicObject  : XPLiteObject
{
    public XPDynamicObject(Session session) : base(session) {}
    public XPDynamicObject(Session session,XPClassInfo classInfo) : base(session,classInfo) { }
}


       Button_Click or any event :

       XPDynamicObject.AutoSaveOnEndEdit = false;

        ReflectionDictionary dic = new ReflectionDictionary();
        var classInfo = dic.CreateClass(dic.GetClassInfo(typeof(XPDynamicObject)),"general.users");

        // WE MUST get schema from database .... via ConnectionProviderSql this is only way 
        var provider = XpoDefault.GetConnectionProvider(MSSqlConnectionProvider.GetConnectionString("(local)","testdb"),AutoCreateOption.None) as ConnectionProviderSql;

        
        // Composite Key - this is only way to add composite key dynamically
        XPComplexCustomMemberInfo user_key = new 
        XPComplexCustomMemberInfo(classInfo,"user_key",typeof(object),new KeyAttribute(),new PersistentAttribute(),new BrowsableAttribute(false));
        user_key.AddSubMember("user_brn",typeof(int),new PersistentAttribute("user_brn"));
        user_key.AddSubMember("user_num",new PersistentAttribute("user_num"));

        var user_name = classInfo.CreateMember("user_name",typeof(string));
        user_name.AddAttribute(new PersistentAttribute("user_name"));
        

        dal = new SimpleDataLayer(dic,provider);

        XPServerCollectionSource xpServerCollectionSource = new XPServerCollectionSource(session,classInfo); // XPServerCollectionSource Only Editable server-mode datasource via ALlowNew,AllowEdit,AllowRemove properties

GridControl.DataSource = xpServerCollectionSource ;

完整备忘单（设计时和运行时 XPO）

要按键或条件搜索对象，请使用以下内容：

编辑：2021-05-24

对于那些询问具有复合键的关联的人。它真的是噩梦。默认情况下，Xpo 不提供。相反，您可以在子类中使用 Session.GetObjectByKey() 并在父类中使用新的 XPCollection。但实际上它有点慢，使用人工密钥的本地方式。

一目了然：使用人工/单键列来改善任何 ORM 兼容性。否则以后在数据库中将是噩梦。如果例如，您支持另一个或替换当前的 ORM。

这是与复合键关联的代码。（请注意，您需要像上图一样动态转换它。您可能需要创建自定义 XPMemberInfo 并覆盖 GetValue() 以返回 Session.GetObjectByKey() 并创建新的 XPCollection。曾经是 Xpo。所以从技术上讲，复合键是不好的方式，除非您需要创建单表将其绑定到网格。例如：- SalesOrderDetail 表没有更多子表）

[Persistent("users")]
public class user : XPLiteObject
{
    public user(Session session) : base(session) { }
    public user(Session session,classInfo) { }

    [Key,Persistent]
    public user_key user_key { get; set; }
    [Persistent("user_name")]
    public string user_name { get; set; }

    private XPCollection<Trans> _trans;
    public XPCollection<Trans> trans
    {
        get
        {
            if (_trans == null)
                _trans = new XPCollection<Trans>(Session,CriteriaOperator.Parse($"user_brn = {user_key.user_brn} AND user_num = {user_key.user_num}"));
            return _trans;
        }
    }

}

public class Trans : XPLiteObject
{
    public Trans(Session session) : base(session) { }
    public Trans(Session session,Persistent("TransID")]
    public int TransID { get; set; }

    public int user_brn { get; set; }
    public int user_num { get; set; }

    public user user
    {
        get
        {
            var key = new user_key();
            key.user_brn = 1;
            key.user_num = 3;
            var obj = Session.GetObjectByKey<user>(key,true);
            return obj;
        }
    }
}

// Composite-Key
public struct user_key
{
    [Persistent("user_brn")]
    public int user_brn { get; set; }
    [Persistent("user_num")]
    public int user_num { get; set; }
}

来自上述模型的动态运行时版本：

    class XPCompositeAssociationMemberInfo : XPCustomMemberInfo
    {
        public XPCompositeAssociationMemberInfo(XPClassInfo owner,string propertyName,Type propertyType,XPClassInfo referenceType,bool nonPersistent,bool nonPublic) : base(owner,propertyName,propertyType,referenceType,nonPersistent,nonPublic)
        {
        }

        public override object GetValue(object theObject)
        {
            XPDynamicObject val = theObject as XPDynamicObject;
            if(val != null)
            {
                var user_num = val.GetMemberValue("user_num");
                IdList vals = new IdList();
                vals.Add(1);
                vals.Add(user_num);
                return val.Session.GetObjectByKey(ReferenceType,vals);
            }
            return val;
        }
    }


  XPDynamicObject.AutoSaveOnEndEdit = false;

        ReflectionDictionary dic = new ReflectionDictionary();
        var userClassInfo = dic.CreateClass(dic.GetClassInfo(typeof(XPDynamicObject)),"users");

        // WE MUST get schema from database .... via ConnectionProviderSql this is only way 
        var provider = XpoDefault.GetConnectionProvider(MSSqlConnectionProvider.GetConnectionString("(local)",AutoCreateOption.None) as ConnectionProviderSql;
        //DBTable Table = provider.GetStorageTables("users")[0];
        
        // Composite Key - this is only way to add composite key dynamically
        XPComplexCustomMemberInfo user_key = new XPComplexCustomMemberInfo(userClassInfo,new PersistentAttribute("user_num"));
        
        var user_name = userClassInfo.CreateMember("user_name",typeof(string));
        user_name.AddAttribute(new PersistentAttribute("user_name"));

        var transClassInfo = dic.CreateClass(dic.GetClassInfo(typeof(XPDynamicObject)),"Trans");
        var TransID = transClassInfo.CreateMember("TransID",new KeyAttribute());
        var user_brn = transClassInfo.CreateMember("user_brn",typeof(int));
        var user_num = transClassInfo.CreateMember("user_num",typeof(int));
        XPCompositeAssociationMemberInfo userMI = new XPCompositeAssociationMemberInfo(transClassInfo,"user",userClassInfo,true,false);



        dal = new SimpleDataLayer(dic,provider);            
        Session session = new Session(dal);
        XPServerCollectionSource xpServerCollectionSource = new XPServerCollectionSource(session,transClassInfo); // XPServerCollectionSource Only Editable server-mode datasource via ALlowNew,AllowRemove properties                        
        xpServerCollectionSource.DisplayableProperties = "TransID;user.user_key.user_num;user.user_name";

最后，重要的！

在运行时实现复合键的情况真的非常非常困难在任何 Xpo 中。而是替换为 Single Column Key(Identity or 人造的。 GUID 一等）

我不知道这是否是您想要的，但我会使用 XPInstantFeedbackSource 分享我的代码。

您可以在 How To Implement The Instant Feedback Mode Xpo

获得更多信息

`XPLiteObject` LogXPOModel

[Persistent("log.t_log")]
public class LogXPOModel : XPLiteObject
{
    [Key,DevExpress.Xpo.DisplayName("id")]
    public long id { get; set; }

    [Key,DevExpress.Xpo.DisplayName("recv_time")]    
    public long recv_time

    ...
}

`Window` 主窗口

public class MainWindow : Window
{
    public XPInstantFeedbackSource SqliteXPInstantFeedbackSource

    public MainWindow() {
        ...
        SqliteXPInstantFeedbackSource = new XPInstantFeedbackSource();
        SqliteXPInstantFeedbackSource.ObjectType = typeof(LogXPOModel);
        SqliteXPInstantFeedbackSource.ResolveSession += SqliteXPInstantFeedbackSource_ResolveSession;
        SqliteXPInstantFeedbackSource.DismissSession += SqliteXPInstantFeedbackSource_DismissSession;
        View.Grid.ItemsSource = SqliteXPInstantFeedbackSource;
    }
    
    ...
}

就像那样——我的桌子有两把钥匙；而且，它不会产生任何问题。

c#c#devexpress devexpress devexpress-gridcontrol xpo

如何使用多个主键表动态创建 DevExpress XPO？

问题描述

解决方法

XPLiteObject LogXPOModel

Window 主窗口

`XPLiteObject` LogXPOModel

`Window` 主窗口