在C的头文件中定义的结构体，如何在cpp文件中引用

#include "dialog3.h"
#include <QDebug>

extern "C"
{
    typedef struct PRINT
    {
        unsigned char Parameters;//BitDepthAC,BitDepthDC,q
        unsigned char PlaneCodes;//指定段的某一个位平面所有的码流
        unsigned char PlaneCodesSeparate;//指定段某个位平面的所有码流，不同的码字是分开的
        unsigned char PlaneIndex;
        unsigned char PlaHit;
        unsigned char AllCodesPrint;//所有的码流，并行，串行
        unsigned short SegIndex;
        unsigned char SegHit;
        unsigned int BlockIndex;
        unsigned char BlockHit;
        unsigned char BlockScanPrint;//指定段中某个块的扫描字
        unsigned char Option;
        unsigned char WordToCode;
        unsigned char BlockCodes;//single block
        unsigned char GagHit;
        unsigned int GagIndex;
        unsigned char BlockBeforeScan;
        unsigned char Header;
        unsigned char DC_DPCM;
        unsigned char DC_RiceCodes;
        unsigned char AC_Depth_DPCM;
        unsigned char AC_DepthRiceCodes;
        unsigned char DC_Additional;
        unsigned char DC_Refinement;
        unsigned char Stage1;
        unsigned char Stage2;
        unsigned char Stage3;
        unsigned char Stage4;
        unsigned char DWT_PRINT;
        unsigned char IDWT_PRINT;

        unsigned char PlaneTime_Print;
        unsigned char ScanTime_Print;

    }PrintPara; 

    extern PrintPara Print;

}

Dialog3::Dialog3(QWidget *parent)
    : QDialog(parent)
{
    ui.setupUi(this);

    ui.checkBox_3->setChecked(true);
    ui.checkBox_4->setChecked(true);
}