给一个DGN中元素添加EC属性

imodel仅能识别符合EC Framework的EC属性。那么如何给一个DGN中的元素添加EC属性呢？下面以举例来实现：

【V8i实现方法】：

1. 下载并解压如下文档到D:\

Fullscreen TestSchema.01.00.ecschema.xml Download

<?xml version="1.0" encoding="utf-8"?>
<ECSchema schemaName="TestSchema" nameSpacePrefix="Myself" version="1.0" xmlns="http://www.bentley.com/schemas/Bentley.ECXML.2.0">
    <ECSchemaReference name="Bentley_Standard_CustomAttributes" version="01.00" prefix="bsca" />
    <ECSchemaReference name="EditorCustomAttributes" version="01.00" prefix="beca" />
    <ECCustomAttributes>
        <SchemaChangeTrackingState xmlns="Bentley_Standard_CustomAttributes.01.00">
            <FinalizationHistory />
            <TrackingEnabled>True</TrackingEnabled>
            <SchemaFullNameAtEditingStart>TestSchema.01.00</SchemaFullNameAtEditingStart>
        </SchemaChangeTrackingState>
    </ECCustomAttributes>
    <ECClass typeName="Component" isStruct="True" isDomainClass="True">
        <ECCustomAttributes>
            <PreviousNameArray xmlns="Bentley_Standard_CustomAttributes.01.00">
                <PreviousNames>
                    <PreviousName>
                        <OldName />
                        <SchemaFullNameKey>TestSchema.01.00</SchemaFullNameKey>
                        <IsNewInThisVersion>True</IsNewInThisVersion>
                    </PreviousName>
                </PreviousNames>
                <PreviousNameAlreadySaved>True</PreviousNameAlreadySaved>
            </PreviousNameArray>
        </ECCustomAttributes>
        <ECProperty propertyName="Name" typeName="string">
            <ECCustomAttributes>
                <PreviousNameArray xmlns="Bentley_Standard_CustomAttributes.01.00">
                    <PreviousNames>
                        <PreviousName>
                            <OldName />
                            <SchemaFullNameKey>TestSchema.01.00</SchemaFullNameKey>
                            <IsNewInThisVersion>True</IsNewInThisVersion>
                        </PreviousName>
                    </PreviousNames>
                    <PreviousNameAlreadySaved>True</PreviousNameAlreadySaved>
                </PreviousNameArray>
                <PropertyPriority xmlns="EditorCustomAttributes.01.00">
                    <Priority>100</Priority>
                </PropertyPriority>
            </ECCustomAttributes>
        </ECProperty>
        <ECProperty propertyName="Style" typeName="string">
            <ECCustomAttributes>
                <PreviousNameArray xmlns="Bentley_Standard_CustomAttributes.01.00">
                    <PreviousNames>
                        <PreviousName>
                            <OldName />
                            <SchemaFullNameKey>TestSchema.01.00</SchemaFullNameKey>
                            <IsNewInThisVersion>True</IsNewInThisVersion>
                        </PreviousName>
                    </PreviousNames>
                    <PreviousNameAlreadySaved>True</PreviousNameAlreadySaved>
                </PreviousNameArray>
                <PropertyPriority xmlns="EditorCustomAttributes.01.00">
                    <Priority>90</Priority>
                </PropertyPriority>
            </ECCustomAttributes>
        </ECProperty>
        <ECProperty propertyName="Description" typeName="string">
            <ECCustomAttributes>
                <PreviousNameArray xmlns="Bentley_Standard_CustomAttributes.01.00">
                    <PreviousNames>
                        <PreviousName>
                            <OldName />
                            <SchemaFullNameKey>TestSchema.01.00</SchemaFullNameKey>
                            <IsNewInThisVersion>True</IsNewInThisVersion>
                        </PreviousName>
                    </PreviousNames>
                    <PreviousNameAlreadySaved>True</PreviousNameAlreadySaved>
                </PreviousNameArray>
                <PropertyPriority xmlns="EditorCustomAttributes.01.00">
                    <Priority>80</Priority>
                </PropertyPriority>
            </ECCustomAttributes>
        </ECProperty>
        <ECProperty propertyName="Corridor" typeName="string">
            <ECCustomAttributes>
                <PreviousNameArray xmlns="Bentley_Standard_CustomAttributes.01.00">
                    <PreviousNames>
                        <PreviousName>
                            <OldName />
                            <SchemaFullNameKey>TestSchema.01.00</SchemaFullNameKey>
                            <IsNewInThisVersion>True</IsNewInThisVersion>
                        </PreviousName>
                    </PreviousNames>
                    <PreviousNameAlreadySaved>True</PreviousNameAlreadySaved>
                </PreviousNameArray>
                <PropertyPriority xmlns="EditorCustomAttributes.01.00">
                    <Priority>70</Priority>
                </PropertyPriority>
            </ECCustomAttributes>
        </ECProperty>
    </ECClass>
</ECSchema>

2. 启动MicroStation V8iSS3或SS4（太早期的版本还不支持i-model功能）；

3. 选中其中任一图形元素，然后依次执行如下键入命令：

MDL LOAD Bentley.ECXAttributesAddin.dll
ECX Schema Import D:\TestSchema.01.00.ecschema.xml
ECX Instance AttachWithStoredSchema TestSchema:Component

4. 用Element Information工具查看这个元素，请将会具有一组新的属性展示出来。

【CE实现方法】：

在MicroStation CONNECT Edition中新增了Item Type功能，它能非常简单地让我们定义这个ECSchema文件并方便地添加Item给图形元素。

具体操作步骤可参考帮助文档。大致是：①通过Drawing工作流下的Contents下的Item Type定义Item Type库（相当于ECSchema和ECClass）

②用Add Item工具给图形元素附加Item。