using System;using System.Drawing;using System.Collections;using System.ComponentModel;using System.Windows.Forms;using System.Data;using System.IO;
namespace WindowsApplication3{ /// <summary> /// Form1 的摘要说明。 /// </summary> public class Form1 : System.Windows.Forms.Form { private System.Windows.Forms.Timer timer1; private System.Windows.Forms.PictureBox pictureBox1; private System.ComponentModel.IContainer components;
public Form1() { // // Windows 窗体设计器支持所必需的 // InitializeComponent();
// // TODO: 在 InitializeComponent 调用后添加任何构造函数代码 // }
/// <summary> /// 清理所有正在使用的资源。 /// </summary> protected override void Dispose( bool disposing ) { if( disposing ) { if (components != null) { components.Dispose(); } } base.Dispose( disposing ); }
#region Windows Form Designer generated code /// <summary> /// 设计器支持所需的方法 - 不要使用代码编辑器修改 /// 此方法的内容。 /// </summary> private void InitializeComponent() { this.components = new System.ComponentModel.Container(); this.timer1 = new System.Windows.Forms.Timer(this.components); this.pictureBox1 = new System.Windows.Forms.PictureBox(); this.SuspendLayout(); // // pictureBox1 // this.pictureBox1.Location = new System.Drawing.Point(16, 16); this.pictureBox1.Name = "pictureBox1"; this.pictureBox1.Size = new System.Drawing.Size(416, 272); this.pictureBox1.TabIndex = 0; this.pictureBox1.TabStop = false; // // Form1 // this.AutoScaleBaseSize = new System.Drawing.Size(6, 14); this.ClientSize = new System.Drawing.Size(472, 310); this.Controls.AddRange(new System.Windows.Forms.Control[] { this.pictureBox1}); this.Name = "Form1"; this.Text = "Form1"; this.Load += new System.EventHandler(this.Form1_Load); this.ResumeLayout(false);
} #endregion
/// <summary> /// 应用程序的主入口点。 /// </summary> [STAThread] static void Main() { Application.Run(new Form1()); }
private void Form1_Load(object sender, System.EventArgs e) { ViewDWG viewDWG=new ViewDWG(); pictureBox1.Image =viewDWG.GetDwgImage("c://1.dwg"); }
} class ViewDWG { struct BITMAPFILEHEADER { public short bfType; public int bfSize; public short bfReserved1; public short bfReserved2; public int bfOffBits; } public Image GetDwgImage(string FileName) { if (!(File.Exists(FileName))) { throw new FileNotFoundException("文件没有被找到"); } FileStream DwgF; //文件流 int PosSentinel; //文件描述块的位置 BinaryReader br; //读取二进制文件 int TypePreview; //缩略图格式 int PosBMP; //缩略图位置 int LenBMP; //缩略图大小 short biBitCount; //缩略图比特深度 BITMAPFILEHEADER biH; //BMP文件头，DWG文件中不包含位图文件头，要自行加上去 byte[] BMPInfo; //包含在DWG文件中的BMP文件体 MemoryStream BMPF = new MemoryStream(); //保存位图的内存文件流 BinaryWriter bmpr = new BinaryWriter(BMPF); //写二进制文件类 Image myImg = null; try { DwgF = new FileStream(FileName, FileMode.Open, FileAccess.Read); //文件流 br = new BinaryReader(DwgF); DwgF.Seek(13, SeekOrigin.Begin); //从第十三字节开始读取 PosSentinel = br.ReadInt32(); //第13到17字节指示缩略图描述块的位置 DwgF.Seek(PosSentinel + 30, SeekOrigin.Begin); //将指针移到缩略图描述块的第31字节 TypePreview = br.ReadByte(); //第31字节为缩略图格式信息，2 为BMP格式，3为WMF格式 if (TypePreview == 1) { } else if (TypePreview == 2 || TypePreview == 3) { PosBMP = br.ReadInt32(); //DWG文件保存的位图所在位置 LenBMP = br.ReadInt32(); //位图的大小 DwgF.Seek(PosBMP + 14, SeekOrigin.Begin); //移动指针到位图块 biBitCount = br.ReadInt16(); //读取比特深度 DwgF.Seek(PosBMP, SeekOrigin.Begin); //从位图块开始处读取全部位图内容备用 BMPInfo = br.ReadBytes(LenBMP); //不包含文件头的位图信息 br.Close(); DwgF.Close(); biH.bfType = 19778; //建立位图文件头 if (biBitCount < 9) { biH.bfSize = 54 + 4 * (int)(Math.Pow(2, biBitCount)) + LenBMP; } else { biH.bfSize = 54 + LenBMP; } biH.bfReserved1 = 0; //保留字节 biH.bfReserved2 = 0; //保留字节 biH.bfOffBits = 14 + 40 + 1024; //图像数据偏移 //以下开始写入位图文件头 bmpr.Write(biH.bfType); //文件类型 bmpr.Write(biH.bfSize); //文件大小 bmpr.Write(biH.bfReserved1); //0 bmpr.Write(biH.bfReserved2); //0 bmpr.Write(biH.bfOffBits); //图像数据偏移 bmpr.Write(BMPInfo); //写入位图 BMPF.Seek(0, SeekOrigin.Begin); //指针移到文件开始处 myImg = Image.FromStream(BMPF); //创建位图文件对象 bmpr.Close(); BMPF.Close(); } return myImg; } catch(Exception ex) { throw new Exception(ex.Message); } } }}
以上代码在vs2002下运行通过
