C# · 12月 28, 2021

C#图片添加水印的实现代码

本文实例介绍了C#图片添加水印的实现方法,可以为图片加文字水印,及判断是否是图片文件,分享给大家供大家参考,具体内容如下

效果图:

以下是HovercWarter类的代码:

using System.Drawing;using System.Drawing.Imaging;using System.IO;namespace HoverTreeBatch.HovercFrame{public class HovercWarter{public static Image AddTextToImg(Image image,string text){Bitmap bitmap = new Bitmap(image,image.Width,image.Height);Graphics g = Graphics.FromImage(bitmap);float fontSize = 12.0f; //字体大小float textWidth = text.Length * fontSize; //文本的长度//下面定义一个矩形区域,以后在这个矩形里画上白底黑字float rectX = 0;float rectY = 0;float rectWidth = text.Length * (fontSize + 8);float rectHeight = fontSize + 8;//声明矩形域RectangleF textArea = new RectangleF(rectX,rectY,rectWidth,rectHeight);Font font = new Font(“宋体”,fontSize); //定义字体Brush whiteBrush = new SolidBrush(Color.White); //白笔刷,画文字用Brush blackBrush = new SolidBrush(Color.Black); //黑笔刷,画背景用g.FillRectangle(blackBrush,rectX,rectHeight);g.DrawString(text,font,whiteBrush,textArea);MemoryStream ms = new MemoryStream();//保存为Jpg类型bitmap.Save(ms,ImageFormat.Jpeg);Image h_hovercImg = Image.FromStream(ms);g.Dispose();bitmap.Dispose();return h_hovercImg;}/// <summary>/// 根据文件头判断上传的文件类型/// </summary>/// <param name=”filePath”>filePath是文件的完整路径 </param>/// <returns>返回true或false</returns>public static bool IsPicture(string filePath){try{FileStream fs = new FileStream(filePath,FileMode.Open,FileAccess.Read);BinaryReader reader = new BinaryReader(fs);string fileClass;byte buffer;buffer = reader.ReadByte();fileClass = buffer.ToString();buffer = reader.ReadByte();fileClass += buffer.ToString();reader.Close();fs.Close();if (fileClass == “255216” || fileClass == “7173” || fileClass == “13780” || fileClass == “6677”)//何问起 hovertree.com//255216是jpg;7173是gif;6677是BMP,13780是PNG;7790是exe,8297是rar {return true;}else{return false;}}catch{return false;}}}}

以上就是C#实现图片添加水印的关键性代码,希望对大家学习C#程序设计有所帮助。