GDI+繪圖技術應用之圖形的保存和打印

一、一定要有個圖形對象Image

       這裏，我們定義一個圖形對象Bitmap imagemap,假定imagemap就是我們繪製出來的圖形對象。

二、給操作界面（WinForm窗體：GraphicsAnalyse）添加一個contextMenu，並給GraphicsAnalyse_Load事件添加腳本

       功能：添加上下文菜單，可以右擊出現如下菜單（包括保存圖形、打印圖形、頁面設置、關閉）

1、給GraphicsAnalyse的ContextMenu屬性添加contextMenu1，使其窗體與contextMenu1關聯。

2、在GraphicsAnalyse_Load事件中添加如下腳本，初始化彈出式菜單

   contextMenu1.MenuItems.Add("保存圖形", new EventHandler(this.Right_Clicked));
   contextMenu1.MenuItems.Add("打印圖形", new EventHandler(this.Right_Clicked));
   contextMenu1.MenuItems.Add("頁面設置", new EventHandler(this.Right_Clicked));
   contextMenu1.MenuItems.Add("-");
   contextMenu1.MenuItems.Add("關閉", new EventHandler(this.Right_Clicked));

3、添加菜單處理程序

  //彈出式菜單項處理程序
  private void Right_Clicked(object sender, System.EventArgs e)
  {

   MenuItem miClicked = (MenuItem)sender;
   string strMenu = ((MenuItem)sender).Text;

   if (strMenu == "保存圖形")
   {
    GraphicSave();
   }
   else if (strMenu == "打印圖形")
   {
    prePrint();
   }
   else if (strMenu == "頁面設置")
   {
    pageSetUp();
   }
   else if (strMenu == "關閉")
   {
    ClsFrameCommunicate.Close();
   }
   else
   {
    return;
   }
  }

4、給“圖形保存”菜單定義一個方法：

  //圖形保存
  private void GraphicSave()
  {
   if (imagemap == null)
   {
    return;
   }
   else
   {
    SaveFileDialog saveDlg = new SaveFileDialog();
    saveDlg.Title = "保存圖形爲...";
    saveDlg.OverwritePrompt = true;
    saveDlg.CheckPathExists = true;
    saveDlg.Filter = "Bitmap files (*.bmp)|*.bmp|Gif File (*.gif)|*.gif|JPEG File (*.jpg)|*.jpg|Png File (*.png)|*.png" ;
    saveDlg.ShowHelp = true;

    if (saveDlg.ShowDialog() == DialogResult.OK)
    {
     string fileName = saveDlg.FileName;
     string strFilExtn = fileName.Remove(0, fileName.Length - 3);

     try
     {
      switch (strFilExtn)
      {
       case "bmp":
        imagemap.Save(fileName, ImageFormat.Bmp);
        break;
       case "jpg":
        imagemap.Save(fileName, ImageFormat.Jpeg);
        break;
       case "png":
        imagemap.Save(fileName, ImageFormat.Png);
        break;
       case "gif":
        imagemap.Save(fileName, ImageFormat.Gif);
        break;
       default:
        break;
      }
     }
     catch(Exception ex)
     {
      MessageBox.Show(ex.Message);
     }
    }
   }
  }

5、給“打印圖形”菜單定義一個方法：

  //圖形打印預覽
  private void prePrint()
  {
   if (strGraphicType == null || strGraphicType =="")
   {
    return;
   }

   try
   {
    hastb["Bitmap"] = imagemap;
    GraphicsPrint gPrint = new GraphicsPrint(hastb);
    try
    {
     gPrint.priviewPrint();
    }
    catch(Exception ex)
    {
     MessageBox.Show("print priview start "+ex.Message);
    }
   }
   catch(Exception ex)
   {
    MessageBox.Show("priview before "+ex.Message);
   }
  }

6、給“頁面設置”定義一個方法

  //圖形頁面設置
  private void pageSetUp()
  {
   if (strGraphicType == null || strGraphicType =="")
   {
    return;
   }

   hastb["GraphicsType"] = strGraphicType;
   hastb["Bitmap"] = imagemap;
   GraphicsPrint gPrint = new GraphicsPrint(hastb);
   gPrint.pageSetup();
  }

7、定義一個圖形打印的類GraphicPrint

using System;
using System.Drawing.Printing;
using System.Configuration;
using System.Drawing;
using System.Collections;
using System.Windows.Forms;

namespace DSSAnalyse
{
 /// <summary>
 /// GraphicsPrint 的摘要說明。
 /// </summary>
 public class GraphicsPrint
 {
  private PrintPreviewDialog previewDlg = null;
  private PageSetupDialog    setupDlg   = null;
  private PrintDocument      printDoc   = null;
  private PrintDialog        printDlg   = null;
  Image imgPrint;
  Hashtable hashTable;

  public GraphicsPrint(Hashtable hast)
  {
   //
   // TODO: 在此處添加構造函數邏輯
   //

   hashTable = hast;
   imgPrint  =(Image)hashTable["Bitmap"];

   //創建打印預覽對話框和其它對話框
   printDoc   = new PrintDocument();
   previewDlg = new PrintPreviewDialog();
   setupDlg   = new PageSetupDialog();
   printDlg   = new PrintDialog();

   printDoc.DocumentName ="圖形打印...";
   previewDlg.Document = printDoc;
   setupDlg.Document   = printDoc;
   printDlg.Document   = printDoc;
   printDlg.AllowSelection = true;
   printDlg.AllowSomePages = true;
   printDoc.PrintPage += new PrintPageEventHandler(this.PrintGraphicsItemsHandler);
  }

  //打印處理程序
  private void PrintGraphicsItemsHandler(object sender, PrintPageEventArgs ppeArgs)
  {
   Graphics g = ppeArgs.Graphics;
   g.DrawImage(imgPrint,0,0);
  }

  //打印預覽程序
  public void priviewPrint()
  {
   previewDlg.UseAntiAlias = true;
   previewDlg.ShowDialog();
  }

  //頁面設置程序
  public void pageSetup()
  {
   if (setupDlg.ShowDialog() == DialogResult.OK)
   {
    printDoc.DefaultPageSettings = setupDlg.PageSettings;
    printDoc.PrinterSettings     = setupDlg.PrinterSettings;
   }
  }
 }
}

8、說明:strGraphicType變量定義當前是什麼圖形，hastb["Bitmap"]中定義了當前的圖形對象，傳入到GraphicPrint類中，以供圖形打印。最終圖形效果如下：