cocos2d::Value
cocos2d::Value
定义在"COCOS2DX_ROOT/cocos/base"的头文件"CCValue.h"中 class Value; 你可以将上面提及的基本类放进 cocos2d::Value底层用一个统一的变量来保存任意基本类型值,它将更加节省内存。在 注意:当处理基本类型和和容器时,请使用 内存管理cocos2d::Value的内存由它的析构函数来释放,所以使用 cocos2d::Value包含下面的数据成员: union { unsigned char byteVal; int intVal; float floatVal; double doubleVal; bool boolVal; }_baseData; std::string _strData; ValueVector* _vectorData; ValueMap* _mapData; ValueMapIntKey* _intKeyMapData; Type _type; 代码段中, 注意: 基本用法ocos2d::Value的用法非常简单直接。 下面就是使用的例子: Value val; // call the default constructor if (val.isNull()) { log("val is null"); }else{ std::string str =val.getDescription(); log("The description of val0:%s",str.c_str()); } //---------------------------------------------------- Value val1(65); // initialize with a integer //Value val1(3.4f); // initialize with a float value //Value val1(3.5); // initialize with a double value log("The description of the integer value:%s",val1.getDescription().c_str()); log("val1.asByte() = %c",val1.asByte()); //---------------------------------------------------- std::string strV = "string"; Value val2(strV); // initialize with string log("The description of the string value:%s",val2.getDescription().c_str()); //---------------------------------------------------- auto sp0 = Sprite::create(); Vector<Object*>* vecV = new Vector<Object*>(); vecV->pushBack(sp0); Value val3(vecV); // initialize with Vector log("The description of the Vector value:%s",val3.getDescription().c_str()); delete vecV; //---------------------------------------------------- Map<std::string,Object*>* mapV = new Map<std::string,Object*>(); mapV->insert(strV,sp0); Value val4(mapV); // initialize with Map log("The description of the Map value:%s",val4.getDescription().c_str()); delete mapV; //---------------------------------------------------- Value val6(&val4); // initialize with Map log("The description of the Value-type value:%s",val6.getDescription().c_str()); //---------------------------------------------------- val2 = val1; // assigning between 2 Value-type log("operator-> The description of val2:%s",val2.getDescription().c_str()); val2 = 4; //assigning directly log("operator-> The description of val4:%s",val2.getDescription().c_str()); 结果是: cocos2d: val is null cocos2d: The description of the integer value: 65 cocos2d: val1.asByte() = A cocos2d: The description of the string value: string cocos2d: The description of the Vector value: true cocos2d: The description of the Map value: true cocos2d: The description of the Value-type value: true cocos2d: operator-> The description of val2: 65 cocos2d: operator-> The description of val4: 4 最佳用法
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