1.从sch_symbol中获取field并传递给lib_symbol

    std::unique_ptr<LIB_SYMBOL> symbol = aSymbol->GetLibSymbolRef()->Flatten();wxCHECK( symbol, /* void */ );std::vector<LIB_FIELD> fullSetOfFields;for( int i = 0; i < (int) aSymbol->GetFields().size(); ++i ){const SCH_FIELD& field = aSymbol->GetFields()[i];VECTOR2I         pos = field.GetPosition() - aSymbol->GetPosition();LIB_FIELD        libField( symbol.get(), field.GetId() );if( i >= MANDATORY_FIELDS && !field.GetName( false ).IsEmpty() )libField.SetName( field.GetName( false ) );libField.SetText( field.GetText() );libField.SetAttributes( field );libField.SetPosition( VECTOR2I( pos.x, -pos.y ) );fullSetOfFields.emplace_back( std::move( libField ) );}symbol->SetFields( fullSetOfFields );

2.获取或修改sch_symbol中的field

sch_symbol.h文件中定义了一个关于SCH_Field的变量：

 std::vector<SCH_FIELD>                 m_fields;    ///< Variable length list of fields.

设置field的值：

设置某个field的值，比如reference的值

static constexpr auto REFERENCE_FIELD = "Reference";
wxString aRef="U";m_fields[ REFERENCE_FIELD ].SetText( aRef );

设置valuefield的值：

void SCH_SYMBOL::SetValueFieldText( const wxString& aValue )
{m_fields[ VALUE_FIELD ].SetText( aValue );
}

valuefield、referencefield都是模板属性，那么普通属性值如何设置呢？

• 首先我们要获取sch_fied，通过名字来获取

SCH_FIELD* FindField( const wxString& aFieldName, bool aIncludeDefaultFields );

SCH_FIELD* SCH_SYMBOL::FindField( const wxString& aFieldName, bool aIncludeDefaultFields )
{unsigned start = aIncludeDefaultFields ? 0 : MANDATORY_FIELDS;for( unsigned i = start; i < m_fields.size(); ++i ){if( aFieldName == m_fields[i].GetName( false ) )return &m_fields[i];}return nullptr;
}

• 然后调用sch_field中的SetText方法

获取field的值：

获取datasheetfield的值：

wxString SCH_SYMBOL::GetDataSheetFiledText(  bool aResolve ) const
{if( aResolve )return GetField( DATASHEET_FIELD )->GetShownText();return GetField( DATASHEET_FIELD )->GetText();
}

datasheetfield是symbol中的模板属性，每个symbol都会有改属性。也有很多属性不是模板属性，这些普通属性的值也可以通过GetFieldText（）获得

wxString SCH_SYMBOL::GetFieldText( const wxString& aFieldName ) const
{for( const SCH_FIELD& field : m_fields ){if( aFieldName == field.GetName() || aFieldName == field.GetCanonicalName() )return field.GetText();}return wxEmptyString;
}