打印图形的类，可图形有时能打印出来，有时就打印不出来

int CP::CreateBmp(int bw, int bh)//创建图像
{
    TLogPalette *lPal;
    int i;

    nos++;
    thebmp[nos] = new Graphics::TBitmap;
    thebmp[nos]->HandleType = bmDIB;
    thebmp[nos]->PixelFormat= pf1bit;
    i = sizeof(TLogPalette) + sizeof(TPaletteEntry) *10 ;
    lPal = (TLogPalette*) malloc(i);
    lPal->palVersion = 0x300;
    lPal->palNumEntries = 2;
    lPal->palPalEntry[0].peRed = 0 ;
    lPal->palPalEntry[0].peGreen = 0 ;
    lPal->palPalEntry[0].peBlue = 0 ;
    lPal->palPalEntry[0].peFlags = 0;
    lPal->palPalEntry[1].peRed =255;
    lPal->palPalEntry[1].peGreen =255;
    lPal->palPalEntry[1].peBlue =255;
    lPal->palPalEntry[1].peFlags = 0;
    thebmp[nos]->Palette = CreatePalette(lPal);
    thebmp[nos]->Width = bw*DotsPerMM;
    thebmp[nos]->Height = bh*DotsPerMM;
    bmpCan[nos] = thebmp[nos]->Canvas;
    free( lPal);
    return nos;
}

void CP::BmpCopy(int x, int y , int bmpindex)   //把图形赋给打印机；bmpindex就是CreateBmp函数所返回的值，就是nos的值
{
    unsigned int BitmapInfoSize, BitmapImageSize;
    long DIBWidth, DIBHeight;
    PChar BitmapImage;
    Windows::PBitmapInfo BitmapInfo;

    x *= DotsPerMM;
    y *= DotsPerMM;
    prBrush->Style = bsClear;//prBrush是打印机的Brush
    GetDIBSizes(thebmp[bmpindex]->Handle, BitmapInfoSize, BitmapImageSize);
    BitmapInfo  = (PBitmapInfo) new char[BitmapInfoSize];
    BitmapImage = (PChar) new char [BitmapImageSize];
    GetDIB(thebmp[bmpindex]->Handle, 0, BitmapInfo, BitmapImage);
    DIBWidth  = BitmapInfo->bmiHeader.biWidth;
    DIBHeight = BitmapInfo->bmiHeader.biHeight;

    StretchDIBits(prCan->Handle,
                x, y, DIBWidth*bpscale, DIBHeight*bpscale,
                0, 0, DIBWidth, DIBHeight,
                BitmapImage, BitmapInfo,
                DIB_RGB_COLORS, SRCCOPY);
    delete BitmapImage;
    BitmapImage=NULL;
    delete BitmapInfo;
    BitmapInfo=NULL;
}

CP::~CP()//删除图像数组
{
    int i;
    for(i = 0 ; i<=nos ; i++)
    {
       delete thebmp[i];
       thebmp[i]=NULL;
    }
}

其中：thebmp[bmpindex]是TBitmap的一个数组，prCan是打印机的Printer()-> Canvas 
DotsPerMM = GetDeviceCaps(prCan->Handle,LOGPIXELSX)/25.399 ;
PixsPermm300 = 300/25.399;
bpscale = GetDeviceCaps(prCan->Handle,LOGPIXELSX)/300;
开始时nos＝－1
是激光打印机