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 的摘要說明。 /// </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 窗體設計器支持所必需的 // InitializeComponent(); // // TODO: 在 InitializeComponent 調用后添加任何構造函數代碼 // } /// <summary> /// 清理所有正在使用的資源。 /// </summary> protected override void Dispose( bool disposing ) { if( disposing ) { if (components != null) { components.Dispose(); } } base.Dispose( disposing ); } #region Windows Form Designer generated code /// <summary> /// 設計器支持所需的方法 - 不要使用代碼編輯器修改 /// 此方法的內容。 /// </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> /// 應用程序的主入口點。 /// </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("文件沒有被找到"); } FileStream DwgF; //文件流 int PosSentinel; //文件描述塊的位置 BinaryReader br; //讀取二進制文件 int TypePreview; //縮略圖格式 int PosBMP; //縮略圖位置 int LenBMP; //縮略圖大小 short biBitCount; //縮略圖比特深度 BITMAPFILEHEADER biH; //BMP文件頭,DWG文件中不包含位圖文件頭,要自行加上去 byte[] BMPInfo; //包含在DWG文件中的BMP文件體 MemoryStream BMPF = new MemoryStream(); //保存位圖的內存文件流 BinaryWriter bmpr = new BinaryWriter(BMPF); //寫二進制文件類 Image myImg = null; try { DwgF = new FileStream(FileName, FileMode.Open, FileAccess.Read); //文件流 br = new BinaryReader(DwgF); DwgF.Seek(13, SeekOrigin.Begin); //從第十三字節開始讀取 PosSentinel = br.ReadInt32(); //第13到17字節指示縮略圖描述塊的位置 DwgF.Seek(PosSentinel + 30, SeekOrigin.Begin); //將指針移到縮略圖描述塊的第31字節 TypePreview = br.ReadByte(); //第31字節為縮略圖格式信息,2 為BMP格式,3為WMF格式 if (TypePreview == 1) { } else if (TypePreview == 2 || TypePreview == 3) { PosBMP = br.ReadInt32(); //DWG文件保存的位圖所在位置 LenBMP = br.ReadInt32(); //位圖的大小 DwgF.Seek(PosBMP + 14, SeekOrigin.Begin); //移動指針到位圖塊 biBitCount = br.ReadInt16(); //讀取比特深度 DwgF.Seek(PosBMP, SeekOrigin.Begin); //從位圖塊開始處讀取全部位圖內容備用 BMPInfo = br.ReadBytes(LenBMP); //不包含文件頭的位圖信息 br.Close(); DwgF.Close(); biH.bfType = 19778; //建立位圖文件頭 if (biBitCount < 9) { biH.bfSize = 54 + 4 * (int)(Math.Pow(2, biBitCount)) + LenBMP; } else { biH.bfSize = 54 + LenBMP; } biH.bfReserved1 = 0; //保留字節 biH.bfReserved2 = 0; //保留字節 biH.bfOffBits = 14 + 40 + 1024; //圖像數據偏移 //以下開始寫入位圖文件頭 bmpr.Write(biH.bfType); //文件類型 bmpr.Write(biH.bfSize); //文件大小 bmpr.Write(biH.bfReserved1); //0 bmpr.Write(biH.bfReserved2); //0 bmpr.Write(biH.bfOffBits); //圖像數據偏移 bmpr.Write(BMPInfo); //寫入位圖 BMPF.Seek(0, SeekOrigin.Begin); //指針移到文件開始處 myImg = Image.FromStream(BMPF); //創建位圖文件對象 bmpr.Close(); BMPF.Close(); } return myImg; } catch(Exception ex) { throw new Exception(ex.Message); } } } }