extra qualification ‘ContourLine::’ on member ‘GetLengthBetweenPoint’ [-fpermissive] 的解决方法

文章源代码如下：

Shapefile.h

class ContourLine
{
public:
	ContourLine();
	//ShapeFile(char *);
	~ContourLine(void);
	void ReadContour(char*);
	void SavaContour(char*);
	vector<Line>  mContours;//等高线
	double MinElevation;
	double MaxElevation;
	int lineNumber;//shpfile数据中线多个数
	int pointNumber;//shpfile数据中点多个数

private:
	char *FilePath; //数据路径

public:
	void SetPath(char *path);
	double ContourLine::GetLengthBetweenPoint(Point P1,Point P2);
	void ContourLine::GetLength(Line& pContour);
public:
	double minx,miny,maxx,maxy;

};

Shapefile.cpp

//构造函数
ContourLine::ContourLine()
{
	OGRRegisterAll();
	pointNumber = 0;
}

ContourLine::~ContourLine(void)
{
}

void ContourLine::ReadContour(char *heightName)
{
	mContours.clear();
	OGRDataSource* poDS = OGRSFDriverRegistrar::Open( this->FilePath, FALSE );
	if( poDS == NULL )
	{
		return;
	}
	OGRLayer* poLayer = poDS->GetLayer(0);
	if (poLayer == NULL)
	{
		return;
	}
	poLayer->ResetReading();
	OGRFeatureDefn *poFDefn = poLayer->GetLayerDefn();
	OGRFeature* poFeature = poLayer->GetNextFeature();
        int number=0;
	Line tempContour;
	while( poFeature != NULL )
	{
			OGRGeometry* poGeometry = poFeature->GetGeometryRef();
			OGRLineString *poPolyline = (OGRLineString *) poGeometry;
			tempContour.Elevation= poFeature->GetFieldAsDouble (heightName);
			if (tempContour.Elevation < 0 || poPolyline->getNumPoints() < 3)
			{
				poFeature = poLayer->GetNextFeature();
				continue;
			}
			int ptNumber = poPolyline->getNumPoints();
			pointNumber +=ptNumber;
			for(int i = 0; i < ptNumber; i++)
			{
				Point Point;
				Point.x=poPolyline->getX(i);
				Point.y=poPolyline->getY(i);
				tempContour.Points.push_back(Point);			

			}			

			//计算tempContour的长度
			this->GetLength(tempContour);

			if(number==0)
			{
					this->MaxElevation=this->MinElevation=tempContour.Elevation;
			}
			else
			{
				if(tempContour.Elevation<this->MinElevation)
                                       this->MinElevation=tempContour.Elevation;
                               if(tempContour.Elevation>this->MaxElevation)
                                       this->MaxElevation=tempContour.Elevation;
			}
			number++;
			mContours.push_back(tempContour);
			tempContour.Points.clear();
		        poFeature = poLayer->GetNextFeature();
	}
	this->lineNumber=number;
}
void ContourLine::SavaContour(char *FilePath)
{
	char FileName[MaxFileNameSize];
	char *p=strrchr(FilePath,'\\')+1;
	strcpy(FileName,p);
	int i=0,j=0;
	while(i<MaxFileNameSize &&FileName[i]!='\0' &&FileName[i]!='.') i++;
        if(i !=MaxFileNameSize) FileName[i]='\0';

   	const char *pszDriverName = "ESRI Shapefile";
        OGRSFDriver *poDriver;
        poDriver = OGRSFDriverRegistrar::GetRegistrar()->GetDriverByName(pszDriverName );
       if( poDriver == NULL )
       {
       		 printf( "%s driver not available.\n", pszDriverName );
        	return;
    	}
       OGRDataSource *poDS;
       poDS = poDriver->CreateDataSource( FilePath, NULL );
       if( poDS == NULL )
       {
           printf( "Creation of output file failed.\n" );
           return;
       }
       OGRLayer *poLayer;
       poLayer = poDS->CreateLayer(FileName, NULL, wkbLineString, NULL );
       if( poLayer == NULL )
       {
             printf( "Layer creation failed.\n" );
             return;
       }
      OGRFieldDefn oField( "contour", OFTReal );
      if( poLayer->CreateField( &oField ) != OGRERR_NONE )
      {
          printf( "Creating  field failed.\n" );
          return;
      }
	int LineNumber=static_cast<int>(mContours.size());
	for(i=0;i<LineNumber;i++)
	{
		OGRFeature *poFeature=new OGRFeature( poLayer->GetLayerDefn() );
		poFeature->SetField( "contour", mContours[i].Elevation );
                OGRLineString *poPolyline = new OGRLineString();
		int num=static_cast<int>(mContours[i].Points.size());
                poPolyline->setNumPoints(num);
                for(j=0;j<num;j++)
		{
			poPolyline->setPoint(j,mContours[i].Points[j].x,mContours[i].Points[j].y);
		}
		poFeature->SetGeometryDirectly(poPolyline);
               if( poLayer->CreateFeature( poFeature ) != OGRERR_NONE )
               {
                      printf( "Failed to create feature in shapefile.\n" );
                      return;
       		 }
	}
    OGRDataSource::DestroyDataSource( poDS );
}

void ContourLine::SetPath(char *path)
{
	FilePath = path;
}

//计算2点之间的距离
double ContourLine::GetLengthBetweenPoint(Point P1,Point P2)
{
	double length;
	length = sqrt((double)((P2.x - P1.x)*(P2.x - P1.x) + (P2.y - P1.y)*(P2.y - P1.y)));
	return length;
}

//计算线pContour的长度，并把长度结果存入length
void ContourLine::GetLength(Line& pContour)
{
	double tempLength;//两点之间的距离
	double totalLength;//一条线的距离
	totalLength = 0;

	//pContour中点的数目
	int lineNumber = pContour.Points.size();
	for(int i = 0; i < lineNumber-1;i++)
	{
		tempLength = GetLengthBetweenPoint(pContour.Points[i],pContour.Points[i+1]);
		totalLength = totalLength + tempLength;
	}

	//返回线段长度
	pContour.Length = totalLength;
}

在用G++编译的时候输入命令：g++ -c Shapefile.cpp -o Shapefile

会提示如下错误：

Shapefile.h:40:9: error: extra qualification ‘ContourLine::’ on member ‘GetLengthBetweenPoint’ [-fpermissive]
Shapefile.h:41:7: error: extra qualification ‘ContourLine::’ on member ‘GetLength’ [-fpermissive]

错误的原因是：类的定义中

double ContourLine::GetLengthBetweenPoint(Point P1,Point P2);
void ContourLine::GetLength(Line& pContour);

不需要用

double ContourLine::，

或者类的函数声明和类的定义是放在一个文件里面，也不许要用***：：

上述错误代码改为

	double GetLengthBetweenPoint(Point P1,Point P2);
	void GetLength(Line& pContour);

OK，编译通过，错误解决。