C++ pi的定义我定义了类CTextclass CText:public CDraw{...protected:con

C++ pi的定义我定义了类CTextclass CText:public CDraw{...protected:const float pi;public:CText();CText(short ColorPen,short ColorBrush,short LineWide,shortLineType,short Layer,int id_only,BOOL Delete,float StartX,float StartY,float Angle1,float Angle2,float TextHeight,float TextWide,float OffWide,unsigned char TextFont,CString Text) :CDraw(ColorPen,ColorBrush,LineWide,LineType,Layer,id_only,Delete),pi(float(3.14159265)) { m_StartX=StartX; m_StartY=StartY; m_Angle1=Angle1; m_Angle2=Angle2; m_TextHeight=TextHeight; m_TextWide=TextWide; m_OffWide=OffWide; m_TextLong=Text.GetLength(); //计算字符长度 c_Text=Text; }}...};但是显示--------------------Configuration: Draw - Win32 Debug--------------------Compiling...Draw.cppDrawDoc.cppDrawView.cppGenerating Code...Linking...DrawDoc.obj : error LNK2001: unresolved external symbol "public: void __thiscall CDraw::DPtoVP(float,float,int *,int *)" (?DPtoVP@CDraw@@QAEXMMPAH0@Z)DrawDoc.obj : error LNK2001: unresolved external symbol "public: int __thiscall CDraw::DLtoVL(float)" (?DLtoVL@CDraw@@QAEHM@Z)Debug/Draw.exe : fatal error LNK1120: 2 unresolved externalsError executing link.exe.Draw.exe - 3 error(s), 0 warning(s)