xBIM 高級03 更改日誌建立

系列目錄    【已更新最新開發文章，點擊查看詳細】 

　　模型中發生的每個變化都是事務的一部分，這是咱們設計的核心。全部事務都是由 IModel 的實現建立的，而且從中被弱引用，所以當使用 using 語句模型時，只要保留事務，就只保留對該事務的引用。這意味着有一個單一的點，全部的變化都在發生，咱們能夠用它們來作一些事情。

　　一件很重要的事情是記錄全部的更改、之前的狀態和下一個狀態。將全部這些結合起來，您能夠建立 back-log 或 forward-log。爲了簡化這個任務，咱們實現了一個 xbim.io.delta.TransactionLog 類。在下面的示例中，咱們將瞭解如何使用它。

using System;
using Xbim.Common;
using Xbim.Ifc;
using Xbim.Ifc4.Interfaces;
using Xbim.IO.Delta;
using Xbim.IO.Step21;


var editor = new XbimEditorCredentials
{
    ApplicationDevelopersName = "You",
    ApplicationFullName = "Your app",
    ApplicationIdentifier = "Your app ID",
    ApplicationVersion = "4.0",
    
    EditorsFamilyName = "Santini Aichel",
    EditorsGivenName = "Johann Blasius",
    EditorsOrganisationName = "Independent Architecture"
};

using (var model = IfcStore.Open("SampleHouse.ifc", editor, true))
{
    using (var txn = model.BeginTransaction("Modification"))
    {
        using (var log = new TransactionLog(txn))
        {
            // 修改一個已經存在的 牆 對象
            var wall = model.Instances.FirstOrDefault<IIfcWall>();
            wall.Name = "Unexpected name";
            wall.GlobalId = Guid.NewGuid().ToPart21();
            wall.Description = "New and more descriptive description";

            // 打印全部由此引發的更改
            PrintChanges(log);
            txn.Commit();
        }
        Console.WriteLine();
    }
}

private static void PrintChanges(TransactionLog log)
{
    foreach (var change in log.Changes)
    {
        switch (change.ChangeType)
        {
            case ChangeType.New:
                Console.WriteLine(@"New entity: {0}", change.CurrentEntity);
                break;
            case ChangeType.Deleted:
                Console.WriteLine(@"Deleted entity: {0}", change.OriginalEntity);
                break;
            case ChangeType.Modified:
                Console.WriteLine(@"Changed Entity: #{0}={1}", change.Entity.EntityLabel, change.Entity.ExpressType.ExpressNameUpper);
                foreach (var prop in change.ChangedProperties)
                    Console.WriteLine(@"        Property '{0}' changed from {1} to {2}", prop.Name, prop.OriginalValue, prop.CurrentValue);
                break;
            default:
                break;
        }
    }
}

生成的更改日誌將以下所示。它包含更多的更改，由於當您更改或建立任何ifcroot實體時，xbim會自動爲您處理全部者歷史記錄。

Changed Entity: #1229=IFCWALL
        Property 'Name' changed from 'Basic Wall:Wall-Ext_102Bwk-75Ins-100LBlk-12P:285330' to 'Unexpected name'
        Property 'OwnerHistory' changed from #42 to #83873
        Property 'GlobalId' changed from '3cUkl32yn9qRSPvBJVyWw5' to '0zxW3$9z95n8U_H9YOcyiE'
        Property 'Description' changed from $ to 'New and more descriptive description'
New entity: #83873=IFCOWNERHISTORY(#83876,#83877,$,.MODIFIED.,$,$,$,0);
New entity: #83874=IFCPERSON($,'Santini Aichel','Johann Blasius',$,$,$,$,$);
New entity: #83875=IFCORGANIZATION($,'Independent Architecture',$,$,$);
New entity: #83876=IFCPERSONANDORGANIZATION(#83874,#83875,$);
New entity: #83878=IFCORGANIZATION($,'You',$,$,$);
New entity: #83877=IFCAPPLICATION(#83878,$,'Your app','Your app ID');

 

系列目錄    【已更新最新開發文章，點擊查看詳細】