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// register as MAXON data type MAXON_DATATYPE (IntegerTriplet, "net.maxonexample.datatype.integertriplet" );

Additionally, the data type must also be registered in a source code file using one of these macros:

• MAXON_DATATYPE_REGISTER : Registers the given class as a data type.
• MAXON_DATATYPE_REGISTER_STRUCT : Registers the given class and its public member variables as a data type.

用法

An instance of a class registered as a MAXON API data type can be stored in a maxon::Data container:

// configure the object IntegerTriplet triplet; triplet._a = 1; triplet._b = 4; triplet._c = 9;

// print the content to the console by invoking ToString() DiagnosticOutput ( "Triplet: @" , triplet);

// storing the object in a maxon::Data container maxon::Data data; data. Set (triplet) iferr_return ;

The data type class can also be identified with a maxon::DataType object. This maxon::DataType can be obtained with maxon::GetDataType() .

// get maxon::DataType const maxon::DataType dataType = maxon::GetDataType<IntegerTriplet>();

// print data type DiagnosticOutput ( "Data Type: @" , dataType);

// init maxon::Data maxon::Data data; data. Init (dataType) iferr_return ;

// get object form maxon::Data const IntegerTriplet triplet = data. Get <IntegerTriplet>() iferr_return ; DiagnosticOutput ( "@" , triplet);

函数

A custom data type class may define and implement these utility functions. These functions may be called by other parts of the MAXON API when using an instance of the data type:

• DescribeIO (): Describes how the internal data of the object should be written to file. See DescribeIO Manual .
• ToString (): Returns a maxon::String representation of the object. See FormatStatement Manual .
• GetHashCode() : Returns a hash value for the object. To implement this one can use maxon::Crc32C , maxon::DefaultCompare or MAXON_HASHCODE .
• GetMemorySize() : Returns the memory size of the object.

注意

To add generic functions see also 类和函数 .

To copy internal data of a data type one has multiple options:

• implementing a copy constructor and operator.
• implementing a CopyFrom() function. This is recommended when copying can fail.

// ------------------------------ // Triplet of maxon::Int values. // ------------------------------ class AdvancedIntegerTriplet { MAXON_DISALLOW_COPY_AND_ASSIGN (AdvancedIntegerTriplet) // no copy constructor, no "=" operator public : AdvancedIntegerTriplet() { _a = 1; _b = 1; _c = 1; }; maxon::Int _a; maxon::Int _b; maxon::Int _c; AdvancedIntegerTriplet(AdvancedIntegerTriplet&& src ) = default ; MAXON_OPERATOR_MOVE_ASSIGNMENT (AdvancedIntegerTriplet); maxon::Result<void> CopyFrom( const AdvancedIntegerTriplet& src ) { _a = src ._a; _b = src ._b; _c = src ._c; return maxon::OK ; } maxon::Bool operator == ( const AdvancedIntegerTriplet& other) const { if (_a != other._a) return false ; if (_b != other._b) return false ; if (_c != other._c) return false ; return true ; } maxon::UInt GetHashCode() const { // create hash code based on the internal data maxon::Crc32C crc; crc. UpdateInt (_a); crc. UpdateInt (_b); crc. UpdateInt (_c); return crc. GetCrc (); } maxon::String ToString ( const maxon::FormatStatement * formatStatement) const { return FormatString ( "@, @, @" , _a, _b, _c); } static maxon::Result<void> DescribeIO ( const maxon::DataSerializeInterface & stream) { iferr_scope ; PrepareDescribe (stream, AdvancedIntegerTriplet); Describe ( "_a" , _a, maxon::Int , maxon::DESCRIBEFLAGS::NONE ) iferr_return ; Describe ( "_b" , _b, maxon::Int , maxon::DESCRIBEFLAGS::NONE ) iferr_return ; Describe ( "_c" , _c, maxon::Int , maxon::DESCRIBEFLAGS::NONE ) iferr_return ; return maxon::OK ; } maxon::Int GetMemorySize() const { return SIZEOF (AdvancedIntegerTriplet); } }; MAXON_DATATYPE (AdvancedIntegerTriplet, "net.maxonexample.datatype.advancedintegertriplet" );

// This example uses a custom data type in order to invoke its default funtions. AdvancedIntegerTriplet triplet; triplet._a = 100; triplet._b = 200; triplet._c = 300;

// call ToString() DiagnosticOutput ( "Triplet: @" , triplet);

// call GetMemorySize() maxon::BaseArray<AdvancedIntegerTriplet> tripletArray; tripletArray. Resize (1000) iferr_return ; const maxon::Int size = tripletArray. GetMemorySize (); DiagnosticOutput ( "Memory Usage: @" , size);

// call CopyFrom() const AdvancedIntegerTriplet newTriplet; tripletArray. Append (newTriplet) iferr_return ;

// call GetHashCode() const maxon::UInt arrayHash = tripletArray. GetHashCode (); DiagnosticOutput ( "Hash Value: @" , arrayHash);

// call DescribeIO()

// file URL const maxon::Url url = (targetFolder + "triplet.data" _s) iferr_return ; maxon::Id fileID( "net.maxonexample.triplet" );

// save to file maxon::DataFormatWriterRef outputStream = maxon::DataFormatWriterFactories::Binary().Create(url) iferr_return ; outputStream.WriteDocument(fileID, maxon::ConstDataPtr (triplet)) iferr_return ; outputStream.CloseOutput() iferr_return ;

// read from file AdvancedIntegerTriplet loadedTriplet; maxon::DataFormatReaderRef inputStream = maxon::DataFormatReaderFactories::Binary().Create(url) iferr_return ; inputStream.ReadDocument(fileID, maxon::DataPtr (loadedTriplet)) iferr_return ; inputStream.CloseInput() iferr_return ; DiagnosticOutput ( "@" , loadedTriplet);

延伸阅读

• 数据 & 算法
• Data Manual
• DataType Manual
• Published Objects