基于soui4实现一个打印排版软件（六）条形码元素控件

条码生成使用了开源库zint。该库实现了全部的常用码制。
在项目头文件中将库导入项目：

//zint
#include "../zint/include/backend/zint.h"
#ifdef _DEBUG
#pragma comment(lib, "../zint/lib/debug/zint.lib")
#else
#pragma comment(lib, "../zint/lib/release/zint.lib")
#endif 

条码元素的移动、拉伸参考rect的实现，这里我们主要看看条码的绘制部分代码

#pragma once
#include "CEleBase.h"
class CEleBarcode : public CEleBase
{
	DEF_SOBJECT(SWindow, L"ele_barcode")
public:
	CEleBarcode();
	~CEleBarcode();
public:
	void OnPaint(IRenderTarget* pRT);
protected:
	LRESULT OnCreate(LPVOID);
	void OnLButtonDown(UINT nFlags, SOUI::CPoint point);
	void OnLButtonUp(UINT nFlags, SOUI::CPoint point);
	void onm ouseMove(UINT nFlags, SOUI::CPoint point);
	void OnLButtonDblClk(UINT nFlags, SOUI::CPoint point);
	void OnRButtonUp(UINT nFlags, CPoint point);

protected:
	SOUI_MSG_MAP_BEGIN()
		MSG_WM_CREATE(OnCreate)
		MSG_WM_PAINT_EX(OnPaint)

		MSG_WM_LBUTTONDOWN(OnLButtonDown)
		MSG_WM_LBUTTONUP(OnLButtonUp)
		MSG_WM_LBUTTONDBLCLK(OnLButtonDblClk)
		MSG_WM_RBUTTONUP(OnRButtonUp)
		MSG_WM_MOUSEMOVE(OnMouseMove)

		SOUI_MSG_MAP_END()
private:
	CPoint  m_ptDown;
	EcPosType m_curEcPosType;
};

#include "stdafx.h"
#include "CEleBarcode.h"

CEleBarcode::CEleBarcode()
{
	//
}

CEleBarcode::~CEleBarcode()
{
	//
}

void CEleBarcode::OnPaint(IRenderTarget* pRT)
{
	SetMsgHandled(FALSE);
	pRT->SetAntiAlias(TRUE);
	CRect rcWindow = GetWindowRect();

	SStringW sstrContent = L"0123456789";
	//计算文本所占的大小
	SIZE szContent;
 	pRT->MeasureText(sstrContent, sstrContent.GetLength(), &szContent);

	//将绘制条码的区域跟绘制文本的区域分开(此处只考虑文本在下方的情况，如有其他的需求可自己实现)
	CRect rcBar(rcWindow);
	rcBar.bottom = rcBar.bottom - szContent.cy;
	CRect rcText(rcWindow);
	rcText.top = rcBar.bottom;

	std::string strContent = S_CW2A(sstrContent);
	struct zint_symbol* symbol;
	symbol = ZBarcode_Create();
	symbol->symbology = BARCODE_CODE128;
	symbol->input_mode = DATA_MODE; //编码格式
	int nRet = ZBarcode_Encode_and_Buffer_Vector(symbol, (unsigned char*)strContent.c_str(), strContent.size(), 0);
	if (nRet == 0)
	{
		ZBarcode_Print(symbol, 0);
		std::vector<CRect> vecLines;
		if (symbol->vector)
		{
			struct zint_vector_rect* rect = symbol->vector->rectangles;
			while (rect)
			{
				CRect rcLine;
				rcLine.left = rect->x;
				rcLine.top = rect->y;
				rcLine.right = rcLine.left + rect->width;
				rcLine.bottom = rcLine.top + rect->height;
				vecLines.push_back(rcLine);
				rect = rect->next;
			}
			double nDrawUint = (double)rcBar.Width() / symbol->width;
			double nUint = (double)symbol->bitmap_width / symbol->width;
			
			CAutoRefPtr<IPathS> path;
			GETRENDERFACTORY->CreatePath(&path);
			for (int i = 0; i < vecLines.size(); i++)
			{
				CRect rcTmp(vecLines[i]);
				rcTmp.left = rcTmp.left / nUint * nDrawUint;
				rcTmp.right = rcTmp.right / nUint * nDrawUint;
				rcTmp.bottom = rcTmp.top + rcBar.Height();
				
				CRect rcBlack;
				rcBlack.left += rcTmp.left + rcBar.left;
				rcBlack.top += rcTmp.top + rcBar.top;
				rcBlack.right = rcBlack.left + rcTmp.Width();
				rcBlack.bottom = rcBlack.top + rcTmp.Height();
				path->addRect(rcBlack);
			}

			COLORREF clrFrg = GETCOLOR(L"RGB(0,0,0)");
			CAutoRefPtr<IBrush> brush, oldbrush;
			pRT->CreateSolidColorBrush(clrFrg, &brush);
			pRT->SelectObject(brush, (IRenderObj**)&oldbrush);
			pRT->FillPath(path);
			pRT->SelectObject(oldbrush, NULL);

			//绘制文本
			{
				pRT->DrawText(sstrContent, -1, (LPRECT)rcText, DT_CENTER | DT_VCENTER | DT_SINGLELINE | DT_NOPREFIX);
			}
		}
	}
	//...
}

LRESULT CEleBarcode::OnCreate(LPVOID)
{
	SetMsgHandled(FALSE);
	//生成元素ID
	std::string strUUID = CGlobalUnits::GetInstance()->GenerateUUID();
	m_strUUID = strUUID;

	return __super::OnCreate(NULL);
}

void CEleBarcode::OnLButtonDown(UINT nFlags, SOUI::CPoint point)
{
	SetMsgHandled(FALSE);
	SetCapture();

	//...
}
void CEleBarcode::OnLButtonUp(UINT nFlags, SOUI::CPoint point)
{
	SetMsgHandled(FALSE);
	ReleaseCapture();
	//...
}
void CEleBarcode::OnMouseMove(UINT nFlags, SOUI::CPoint point)
{
	SetMsgHandled(FALSE);
	//...
}
void CEleBarcode::OnLButtonDblClk(UINT nFlags, SOUI::CPoint point)
{
	SetMsgHandled(FALSE);
}
void CEleBarcode::OnRButtonUp(UINT nFlags, CPoint point)
{
	SetMsgHandled(FALSE);
}

控件使用：
先注册，再在容器中创建元素

m_theApp->RegisterWindowClass<CEleBarcode>();

	CEleBarcode* pEle = (CEleBarcode*)SApplication::getSingleton().CreateWindowByName(L"ele_barcode");
	SASSERT(pEle);
	SApplication::getSingleton().SetSwndDefAttr(pEle);
	this->InsertChild(pEle);
	pEle->SSendMessage(WM_CREATE);
	CPoint ptReal(point);
	ptReal.x -= rcContainer.left;
	ptReal.y -= rcContainer.top;

	SStringT sstrRectPos;
	sstrRectPos.Format(_T("%d,%d,@%d,@%d"), ptReal.x, ptReal.y, 100, 30);
	pEle->SetAttribute(L"pos", sstrRectPos);

	//将位置、长宽等信息转为毫米
	CPoint ptRB(ptReal.x + 100, ptReal.y + 30);
	pEle->m_ptLT = ptReal;
	pEle->m_ptRB = ptRB;

以上就是条码控件的实现以及使用，此处只实现了CODE128码，其他码制的实现类似。需要注意的是这里文本跟条码的绘制是分开绘制的。如果是EAN8、EAN13、UPCA或者UPCE此类长短不一的线条还需要做特殊的处理。