網頁WEB打印控件制作-開放源碼

 在WEB系統中，打印的確是比較煩人的問題，如果我們能制作一個屬于自己的自定義的打印插件，那么我們在后續自定義打印的時候能隨心所欲的控制打印，這樣的效果對于程序員來說是非常開心的一件事件，本文將自己開發編寫的C# 制作的HTML打印插件分享出來，讓有同樣需求的朋友提供一個參考；此插件是基于Microsoft .NET Framework 2.0 開發的，缺點是每臺客戶端在安裝插件時，必須要安裝Microsoft .NET Framework 2.0 ；本插件能實現 頁眉、頁腳、表頭、標題、表尾的分頁打印；支持紙張類型、自動補充空行等功能；由于技術有限，肯定有很多不足的地方，請批評指正！

由于本打印插件是基于我們開發平臺的報表基礎來開發設計的，所以打印控件的原理：通過JS將頁面表格數據生成固定格式的XML字符串（圖片通過64base圖片格式）傳送給打印插件，有打印插件自主繪圖生成打印頁面。E_Print插件可以在WEB或WinForm中使用：

打印插件完整源碼：E_Print.rar （包含插件源碼、打包程序、winform調試DEMO）

下面貼出源碼：（在源碼中有詳細的注釋說明）

 using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
namespace E_Print
{
    /// <summary>
    /// 分頁計算
    /// </summary>
    public class PagingCalc
    {
        #region 私有變量
        /// <summary>
        /// 表格區域
        /// </summary>
        private RectangleF _tableRect;
        /// <summary>
        /// 報表行集
        /// </summary>
        private List<Row> _rowsList;
        /// <summary>
        /// 是否每頁打印標題
        /// </summary>
        private bool _isAllPrintTitle;
        /// <summary>
        /// 是否每頁打印表頭
        /// </summary>
        private bool _isAllPrintHead;
        /// <summary>
        /// 是否每頁打印表尾
        /// </summary>
        private bool _isAllPrintFoot;
        /// <summary>
        /// 標題行集
        /// </summary>
        private List<Row> TitleList;
        /// <summary>
        /// 表頭前行集
        /// </summary>
        private List<Row> HForeList;
        /// <summary>
        /// 表頭行集
        /// </summary>
        private List<Row> HeadList;
        /// <summary>
        /// 數據行集
        /// </summary>
        private List<Row> DataList;
        /// <summary>
        /// 表尾行集
        /// </summary>
        private List<Row> FootList;
        /// <summary>
        /// 每頁打印標題+表頭高度
        /// </summary>
        private float _myHeadPix;
        /// <summary>
        /// 每頁打印表尾高度
        /// </summary>
        private float _myFootPix;
        #endregion
        #region 構造方法
        /// <summary>
        /// 構造函數
        /// </summary>
        public PagingCalc()
        {
            _tableRect = new RectangleF();
            _rowsList = new List<Row>();
            _isAllPrintTitle = false;
            _isAllPrintHead = false;
            _isAllPrintFoot = false;
            TitleList = new List<Row>();
            HForeList = new List<Row>();
            HeadList = new List<Row>();
            DataList = new List<Row>();
            FootList = new List<Row>();
            _myHeadPix = 0;
            _myFootPix = 0;
        }
        #endregion
        #region 屬性方法
        /// <summary>
        /// 獲取--設置--表格區域
        /// </summary>
        public RectangleF TableRect
        {
            get { return _tableRect; }
            set { _tableRect = value; }
        }
        /// <summary>
        /// 獲取--設置--表格行集
        /// </summary>
        public List<Row> RowsList
        {
            get { return _rowsList; }
            set { _rowsList = value; }
        }
        /// <summary>
        /// 獲取--設置--是否每頁打印標題
        /// </summary>
        public bool IsAllPrintTitle
        {
            get { return _isAllPrintTitle; }
            set { _isAllPrintTitle = value; }
        }
        /// <summary>
        /// 獲取--設置--是否每頁打印表頭
        /// </summary>
        public bool IsAllPrintHead
        {
            get { return _isAllPrintHead; }
            set { _isAllPrintHead = value; }
        }
        /// <summary>
        /// 獲取--設置--是否每頁打印表尾
        /// </summary>
        public bool IsAllPrintFoot
        {
            get { return _isAllPrintFoot; }
            set { _isAllPrintFoot = value; }
        }
        /// <summary>
        /// 獲取--設置--每頁打印標題+表頭高度
        /// </summary>
        public float MyHeadPix
        {
            get { return _myHeadPix; }
            set { _myHeadPix = value; }
        }
        /// <summary>
        /// 獲取--設置--每頁打印表尾巴高度
        /// </summary>
        public float MyFootPix
        {
            get { return _myFootPix; }
            set { _myFootPix = value; }
        }
        #endregion
        #region 計算方法
        /// <summary>
        /// 分頁計算
        /// </summary>
        /// <returns></returns>
        public List<PagingItem> CalcPages()
        {
            List<PagingItem> retPages = new List<PagingItem>();
            // 無需分頁
            if (Get_TableAllHeight() <= TableRect.Height)
            {
                PagingItem tmItem0 = new PagingItem();
                tmItem0.PageNum = 1;
                for (int y = 0; y < RowsList.Count; y++)
                {
                    tmItem0.IndexList.Add(y);
                }
                retPages.Add(tmItem0);
            }
            else  // 需要分頁
            {
                // 有設置了 每頁打印標題、表頭、表位 其中的任意一個
                if (Get_IsCusSet_THDF())  // 則執行每頁相對分頁
                {
                    Paging_Relative(0, ref retPages);
                    // 計算每頁打印頭尾高度
                    MyHeadPix = 0;
                    if (IsAllPrintTitle)
                    {
                        MyHeadPix += Get_TableTileHeight();
                    }
                    if (IsAllPrintHead)
                    {
                        MyHeadPix += Get_TableHeadHeight();
                    }
                    if (IsAllPrintFoot)
                    {
                        MyFootPix = Get_TableFootHeight();
                    }
                }
                else  // 執行直接數據分頁
                {
                    Paging_Direct(0, ref retPages);
                }
            }
            return retPages;
        }
        /// <summary>
        /// 直接分頁
        /// </summary>
        /// <param name="startR">開始行號</param>
        /// <param name="pages">頁面數組</param>
        private void Paging_Direct(int startR, ref  List<PagingItem> pages)
        {
            float p_Height = TableRect.Height;
            PagingItem p_Item = new PagingItem();
            p_Item.PageNum = pages.Count + 1;
            for (int t = startR; t < RowsList.Count; t++)
            {
                // 檢查行內單元格是否不允許分頁兩種情況：條形碼,圖片
                if (Paging_CheckCell(RowsList[t], p_Height))
                {
                    startR = t;
                    pages.Add(p_Item);
                    Paging_Direct(startR, ref pages);
                    break;
                }
                else
                {
                    p_Height -= RowsList[t].RowHeight;
                    if (p_Height <= 0)
                    {
                        startR = t;
                        pages.Add(p_Item);
                        Paging_Direct(startR, ref pages);
                        break;
                    }
                    else
                    {
                        p_Item.IndexList.Add(t);
                        if (t == RowsList.Count - 1)
                        {
                            pages.Add(p_Item);
                        }
                    }
                }
            }
        }
        /// <summary>
        /// 相對分頁
        /// </summary>
        /// <param name="startR">開始序號</param>
        /// <param name="pages">頁面數組</param>
        private void Paging_Relative(int startR, ref  List<PagingItem> pages)
        {
            SplitReportArea();                     // 拆分表行
            float p_Height = TableRect.Height;     // 頁面總高
            PagingItem p_Item = new PagingItem();  // 分頁頁面
            p_Item.PageNum = pages.Count + 1;      // 分頁頁碼
            bool runNext = false;                  // 繼續分頁
            #region 每頁打印標題
            // 每頁打印標題
            if (IsAllPrintTitle)
            {
                p_Height -= Get_TableTileHeight();
                foreach (Row p_Row in TitleList)
                    p_Item.IndexList.Add(p_Row.RowIndex);
            }
            else
            {
                if (p_Item.PageNum == 1)  // 第一頁特殊處理
                {
                    p_Height -= Get_TableTileHeight();
                    foreach (Row p_Row in TitleList)
                        p_Item.IndexList.Add(p_Row.RowIndex);
                }
            }
            #endregion
            #region 每頁打印表頭
            // 每頁打印表頭
            if (IsAllPrintHead)
            {
                if (p_Item.PageNum == 1)  // 第一頁特殊處理
                {
                    // 計算表頭前的行高
                    p_Height -= Get_TableHForHeight();
                    foreach (Row p_Row in HForeList)
                        p_Item.IndexList.Add(p_Row.RowIndex);
                }
                // 計算表頭行的高度
                p_Height -= Get_TableHeadHeight();
                foreach (Row p_Row in HeadList)
                    p_Item.IndexList.Add(p_Row.RowIndex);
            }
            else
            {
                if (p_Item.PageNum == 1)  // 第一頁特殊處理
                {
                    // 計算表頭前的行高
                    p_Height -= Get_TableHForHeight();
                    foreach (Row p_Row in HForeList)
                        p_Item.IndexList.Add(p_Row.RowIndex);
                    // 計算表頭行的高度
                    p_Height -= Get_TableHeadHeight();
                    foreach (Row p_Row in HeadList)
                        p_Item.IndexList.Add(p_Row.RowIndex);
                }
            }
            #endregion
            #region 每頁數據區域
            // 每頁數據劃分
            if (IsAllPrintFoot)
            {
                p_Height -= Get_TableFootHeight();             // 表格高度 先減去表尾的高度
            }
            for (int t = startR; t < DataList.Count; t++)
            {
                // 檢查行內單元格是否不允許分頁兩種情況：條形碼,圖片
                if (Paging_CheckCell(DataList[t], p_Height))  // 此情況下，單元格不能分割，并且高度超過頁面剩余高度，所以要啟動新的一頁
                {
                    startR = t;
                    runNext = true;
                    break;
                }
                else
                {
                    p_Height -= DataList[t].RowHeight;
                    if (p_Height <= 0)
                    {
                        startR = t;
                        runNext = true;
                        break;
                    }
                    else
                    {
                        p_Item.IndexList.Add(DataList[t].RowIndex);
                    }
                }
            }
            #endregion
            #region 每頁打印表尾
            // 每頁打印表尾
            if (IsAllPrintFoot)
            {
                foreach (Row p_Row in FootList)
                    p_Item.IndexList.Add(p_Row.RowIndex);
            }
            #endregion
            #region 添加分頁頁面
            pages.Add(p_Item);
            if (runNext)
            {
                Paging_Relative(startR, ref pages);
            }
            #endregion
        }
        /// <summary>
        /// 檢查行內單元格如果是圖片
        /// 并且合并行數大于1
        /// </summary>
        /// <param name="cRow"></param>
        /// <param name="cHeight"></param>
        /// <returns></returns>
        private bool Paging_CheckCell(Row cRow, float cHeight)
        {
            foreach (Cell cCell in cRow.RowCells)
            {
                if (cCell.IsImage == true)
                {
                    if (cCell.RectH > cHeight)
                        return true;
                }
            }
            return false;
        }
        #endregion
        #region 輔助方法
        /// <summary>
        /// 獲取--報表全部高度
        /// </summary>
        /// <returns></returns>
        private float Get_TableAllHeight()
        {
            float retHight = 0;
            for (int k = 0; k < RowsList.Count; k++)
            {
                Row t_Row = RowsList[k];
                retHight += t_Row.RowHeight;
            }
            return retHight;
        }
        /// <summary>
        /// 獲取是否設置了標題、表頭、表尾 中的任意一個
        /// </summary>
        /// <returns></returns>
        private bool Get_IsCusSet_THDF()
        {
            string tmType = "";
            foreach (Row cusRow in this.RowsList)
            {
                tmType = cusRow.RowType.ToLower().Trim();
                if (tmType == "t" || tmType == "h" || tmType == "f")
                    return true;
            }
            return false;
        }
        /// <summary>
        /// 獲取--報表標題高度
        /// </summary>
        /// <returns></returns>
        private float Get_TableTileHeight()
        {
            float retHight = 0;
            for (int k = 0; k < TitleList.Count; k++)
                retHight += TitleList[k].RowHeight;
            return retHight;
        }
        /// <summary>
        /// 獲取--報表表頭前高度
        /// </summary>
        /// <returns></returns>
        private float Get_TableHForHeight()
        {
            float retHight = 0;
            for (int k = 0; k < HForeList.Count; k++)
                retHight += HForeList[k].RowHeight;
            return retHight;
        }
        /// <summary>
        /// 獲取--報表表頭高度
        /// </summary>
        /// <returns></returns>
        private float Get_TableHeadHeight()
        {
            float retHight = 0;
            for (int k = 0; k < HeadList.Count; k++)
                retHight += HeadList[k].RowHeight;
            return retHight;
        }
        /// <summary>
        /// 獲取--報表表尾高度
        /// </summary>
        /// <returns></returns>
        private float Get_TableFootHeight()
        {
            float retHight = 0;
            for (int k = 0; k < FootList.Count; k++)
                retHight += FootList[k].RowHeight;
            return retHight;
        }
        /// <summary>
        /// 拆分報表區域
        /// </summary>
        public void SplitReportArea()
        {
            TitleList = new List<Row>();
            HForeList = new List<Row>();
            HeadList = new List<Row>();
            DataList = new List<Row>();
            FootList = new List<Row>();
            for (int m = 0; m < RowsList.Count; m++)
            {
                Row mmRow = RowsList[m];
                switch (mmRow.RowType.ToLower())
                {
                    case "t": // 標題
                        TitleList.Add(mmRow);
                        break;
                    case "h": // 表頭
                        HeadList.Add(mmRow);
                        break;
                    case "f": // 表尾
                        FootList.Add(mmRow);
                        break;
                    case "d": // 數據
                    default:
                        DataList.Add(mmRow);
                        break;
                }
            }

            // 設置表頭前行集
            if (TitleList.Count == 0 && HeadList.Count > 0)
            {
                List<Row> tmpList = new List<Row>();
                for (int n = 0; n < DataList.Count; n++)
                {
                    if (DataList[n].RowIndex < HeadList[0].RowIndex)
                    {
                        HForeList.Add(DataList[n]);
                        tmpList.Add(DataList[n]);
                    }
                }
                for (int n = 0; n < tmpList.Count; n++)
                {
                    DataList.Remove(tmpList[n]);
                }
                tmpList.Clear();
            }
            // 重設表尾  不是每頁打印表尾情況下，那么表位就去掉
            if (!IsAllPrintFoot)
            {
                foreach (Row tRow in FootList)
                    DataList.Add(tRow);
                FootList.Clear();
            }
        }
        #endregion
    }
}