本文要提供的類可以為圖片加文字水印,以及判斷是否是圖片文件。經過測試可運行,例子請下載:http://hovertree.com/h/bjaf/5qc5eh6y.htm
例子效果圖:

以下是HovercWarter類的代碼:
1 using System.Drawing; 2 using System.Drawing.Imaging; 3 using System.IO; 4 5 namespace HoverTreeBatch.HovercFrame 6 { 7 public class HovercWarter 8 { 9 public static Image AddTextToImg(Image image, string text)10 {11 Bitmap bitmap = new Bitmap(image, image.Width, image.Height);12 Graphics g = Graphics.FromImage(bitmap);13 14 float fontSize = 12.0f; //字體大小15 float textWidth = text.Length * fontSize; //文本的長度16 //下面定義一個矩形區域,以后在這個矩形里畫上白底黑字17 float rectX = 0;18 float rectY = 0;19 float rectWidth = text.Length * (fontSize + 8);20 float rectHeight = fontSize + 8;21 //聲明矩形域22 RectangleF textArea = new RectangleF(rectX, rectY, rectWidth, rectHeight);23 24 Font font = new Font("宋體", fontSize); //定義字體25 Brush whiteBrush = new SolidBrush(Color.White); //白筆刷,畫文字用26 Brush blackBrush = new SolidBrush(Color.Black); //黑筆刷,畫背景用27 28 g.FillRectangle(blackBrush, rectX, rectY, rectWidth, rectHeight);29 30 g.DrawString(text, font, whiteBrush, textArea);31 MemoryStream ms = new MemoryStream();32 //保存為Jpg類型33 bitmap.Save(ms, ImageFormat.Jpeg);34 35 Image h_hovercImg = Image.FromStream(ms);36 37 g.Dispose();38 bitmap.Dispose();39 40 41 return h_hovercImg;42 }43 44 45 /// <summary>46 /// 根據文件頭判斷上傳的文件類型47 /// </summary>48 /// <param name="filePath">filePath是文件的完整路徑 </param>49 /// <returns>返回true或false</returns>50 public static bool IsPicture(string filePath)51 {52 try53 {54 FileStream fs = new FileStream(filePath, FileMode.Open, Fileaccess.Read);55 BinaryReader reader = new BinaryReader(fs);56 string fileClass;57 byte buffer;58 buffer = reader.ReadByte();59 fileClass = buffer.ToString();60 buffer = reader.ReadByte();61 fileClass += buffer.ToString();62 reader.Close();63 fs.Close();64 if (fileClass == "255216" || fileClass == "7173" || fileClass == "13780" || fileClass == "6677")65 //何問起 hovertree.com66 //255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar 67 {68 return true;69 }70 else71 {72 return false;73 }74 }75 catch76 {77 return false;78 }79 }80 }81 }
另外出一道.NET的題目:http://hovertree.com/shortanswer/bjaf/9vqxwuda.htm
開發技術文章收集: http://m.survivalescaperooms.com/sosoft/p/kaifajishu.html
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