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asp .net实现给图片添加图片水印方法示例

时间:2021-07-01 10:21:17 帮助过:22人阅读

前言

本文主要给大家介绍的是asp .net实现给图片添加图片水印的方法,注意是图片水印,需要的朋友们可以参考学习,下面话不多说来看看详细的介绍吧。

方法如下

首先写好一个写入图片水印的类,先创建一个ImageWriter类库   (该类中有包含枚举类型和方法)

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Text;
  5. using System.IO;
  6. using System.Collections;
  7. using System.Drawing;
  8. using System.Drawing.Drawing2D;
  9. using System.Drawing.Imaging;
  10. namespace ImageWriter
  11. {
  12. /// <summary>
  13. /// 图片处理类
  14. /// </summary>
  15. public class ImageManager
  16. {
  17. #region 变量声明开始
  18. /// <summary>
  19. /// 枚举: 水印位置
  20. /// </summary>
  21. public enum WatermarkPosition
  22. {
  23. /// <summary>
  24. /// 左上
  25. /// </summary>
  26. LeftTop,
  27. /// <summary>
  28. /// 左中
  29. /// </summary>
  30. Left,
  31. /// <summary>
  32. /// 左下
  33. /// </summary>
  34. LeftBottom,
  35. /// <summary>
  36. /// 正上
  37. /// </summary>
  38. Top,
  39. /// <summary>
  40. /// 正中
  41. /// </summary>
  42. Center,
  43. /// <summary>
  44. /// 正下
  45. /// </summary>
  46. Bottom,
  47. /// <summary>
  48. /// 右上
  49. /// </summary>
  50. RightTop,
  51. /// <summary>
  52. /// 右中
  53. /// </summary>
  54. RightCenter,
  55. /// <summary>
  56. /// 右下
  57. /// </summary>
  58. RigthBottom
  59. }
  60. #endregion 变量声明结束
  61. #region 构造函数开始
  62. /// <summary>
  63. /// 构造函数: 默认
  64. /// </summary>
  65. public ImageManager()
  66. { }
  67. #endregion 构造函数结束
  68. #region 私有函数开始
  69. /// <summary>
  70. /// 获取: 图片去扩展名(包含完整路径及其文件名)小写字符串
  71. /// </summary>
  72. /// <param name="path">图片路径(包含完整路径,文件名及其扩展名): string</param>
  73. /// <returns>返回: 图片去扩展名(包含完整路径及其文件名)小写字符串: string</returns>
  74. private string GetFileName(string path)
  75. {
  76. return path.Remove(path.LastIndexOf('.')).ToLower();
  77. }
  78. /// <summary>
  79. /// 获取: 图片以'.'开头的小写字符串扩展名
  80. /// </summary>
  81. /// <param name="path">图片路径(包含完整路径,文件名及其扩展名): string</param>
  82. /// <returns>返回: 图片以'.'开头的小写字符串扩展名: string</returns>
  83. private string GetExtension(string path)
  84. {
  85. return path.Remove(0, path.LastIndexOf('.')).ToLower();
  86. }
  87. /// <summary>
  88. /// 获取: 图片以 '.' 开头的小写字符串扩展名对应的 System.Drawing.Imaging.ImageFormat 对象
  89. /// </summary>
  90. /// <param name="format">以 '. '开头的小写字符串扩展名: string</param>
  91. /// <returns>返回: 图片以 '.' 开头的小写字符串扩展名对应的 System.Drawing.Imaging.ImageFormat 对象: System.Drawing.Imaging.ImageFormat</returns>
  92. private ImageFormat GetImageFormat(string format)
  93. {
  94. switch (format)
  95. {
  96. case ".bmp":
  97. return ImageFormat.Bmp;
  98. case ".emf":
  99. return ImageFormat.Emf;
  100. case ".exif":
  101. return ImageFormat.Exif;
  102. case ".gif":
  103. return ImageFormat.Gif;
  104. case ".ico":
  105. return ImageFormat.Icon;
  106. case ".png":
  107. return ImageFormat.Png;
  108. case ".tif":
  109. return ImageFormat.Tiff;
  110. case ".tiff":
  111. return ImageFormat.Tiff;
  112. case ".wmf":
  113. return ImageFormat.Wmf;
  114. default:
  115. return ImageFormat.Jpeg;
  116. }
  117. }
  118. /// <summary>
  119. /// 获取: 枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition 对应的 System.Drawing.Rectangle 对象
  120. /// </summary>
  121. /// <param name="positon">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition: Uinatlex.ToolBox.ImageManager.WatermarkPosition</param>
  122. /// <param name="X">原图宽度: int</param>
  123. /// <param name="Y">原图高度: int</param>
  124. /// <param name="x">水印宽度: int</param>
  125. /// <param name="y">水印高度: int</param>
  126. /// <param name="i">边距: int</param>
  127. /// <returns>返回: 枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition 对应的 System.Drawing.Rectangle 对象: System.Drawing.Rectangle</returns>
  128. private Rectangle GetWatermarkRectangle(WatermarkPosition positon, int X, int Y, int x, int y, int i)
  129. {
  130. switch (positon)
  131. {
  132. case WatermarkPosition.LeftTop:
  133. return new Rectangle(i, i, x, y);
  134. case WatermarkPosition.Left:
  135. return new Rectangle(i, (Y - y) / 2, x, y);
  136. case WatermarkPosition.LeftBottom:
  137. return new Rectangle(i, Y - y - i, x, y);
  138. case WatermarkPosition.Top:
  139. return new Rectangle((X - x) / 2, i, x, y);
  140. case WatermarkPosition.Center:
  141. return new Rectangle((X - x) / 2, (Y - y) / 2, x, y);
  142. case WatermarkPosition.Bottom:
  143. return new Rectangle((X - x) / 2, Y - y - i, x, y);
  144. case WatermarkPosition.RightTop:
  145. return new Rectangle(X - x - i, i, x, y);
  146. case WatermarkPosition.RightCenter:
  147. return new Rectangle(X - x - i, (Y - y) / 2, x, y);
  148. default:
  149. return new Rectangle(X - x - i, Y - y - i, x, y);
  150. }
  151. }
  152. #endregion 私有函数结束
  153. #region 文字生成开始
  154. #endregion 文字生成结束
  155. #region 设置透明度开始
  156. /// <summary>
  157. /// 设置: 图片 System.Drawing.Bitmap 对象透明度
  158. /// </summary>
  159. /// <param name="sBitmap">图片 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param>
  160. /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param>
  161. /// <returns>图片 System.Drawing.Bitmap: System.Drawing.Bitmap</returns>
  162. public Bitmap SetTransparence(Bitmap bm, float transparence)
  163. {
  164. if (transparence == 0.0f || transparence == 1.0f)
  165. throw new ArgumentException("透明度值只能在0.0f~1.0f之间");
  166. float[][] floatArray =
  167. {
  168. new float[] { 1.0f, 0.0f, 0.0f, 0.0f, 0.0f },
  169. new float[] { 0.0f, 1.0f, 0.0f, 0.0f, 0.0f },
  170. new float[] { 0.0f, 0.0f, 1.0f, 0.0f, 0.0f },
  171. new float[] { 0.0f, 0.0f, 0.0f, transparence, 0.0f },
  172. new float[] { 0.0f, 0.0f, 0.0f, 0.0f, 1.0f }
  173. };
  174. ImageAttributes imageAttributes = new ImageAttributes();
  175. imageAttributes.SetColorMatrix(new ColorMatrix(floatArray), ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
  176. Bitmap bitmap = new Bitmap(bm.Width, bm.Height);
  177. Graphics graphics = Graphics.FromImage(bitmap);
  178. graphics.DrawImage(bm, new Rectangle(0, 0, bm.Width, bm.Height), 0, 0, bm.Width, bm.Height, GraphicsUnit.Pixel, imageAttributes);
  179. graphics.Dispose();
  180. imageAttributes.Dispose();
  181. bm.Dispose();
  182. return bitmap;
  183. }
  184. /// <summary>
  185. /// 设置: 图片 System.Drawing.Bitmap 对象透明度
  186. /// </summary>
  187. /// <param name="readpath">图片路径(包含完整路径,文件名及其扩展名): string</param>
  188. /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param>
  189. /// <returns>图片 System.Drawing.Bitmap: System.Drawing.Bitmap</returns>
  190. public Bitmap SetTransparence(string readpath, float transparence)
  191. {
  192. return SetTransparence(new Bitmap(readpath), transparence);
  193. }
  194. #endregion 设置透明度结束
  195. #region 添加水印开始
  196. /// <summary>
  197. /// 生成: 原图绘制水印的 System.Drawing.Bitmap 对象
  198. /// </summary>
  199. /// <param name="sBitmap">原图 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param>
  200. /// <param name="wBitmap">水印 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param>
  201. /// <param name="position">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition : Uinatlex.ToolBox.ImageManager.WatermarkPosition</param>
  202. /// <param name="margin">水印边距: int</param>
  203. /// <returns>返回: 原图绘制水印的 System.Drawing.Bitmap 对象 System.Drawing.Bitmap</returns>
  204. public Bitmap CreateWatermark(Bitmap sBitmap, Bitmap wBitmap, WatermarkPosition position, int margin)
  205. {
  206. Graphics graphics = Graphics.FromImage(sBitmap);
  207. graphics.DrawImage(wBitmap, GetWatermarkRectangle(position, sBitmap.Width, sBitmap.Height, wBitmap.Width, wBitmap.Height, margin));
  208. graphics.Dispose();
  209. wBitmap.Dispose();
  210. return sBitmap;
  211. }
  212. #endregion 添加水印结束
  213. #region 图片切割开始
  214. #endregion 图片切割结束
  215. #region 图片缩放开始
  216. #endregion 图片缩放结束
  217. #region 保存图片到文件开始
  218. #region 普通保存开始
  219. /// <summary>
  220. /// 保存: System.Drawing.Bitmap 对象到图片文件
  221. /// </summary>
  222. /// <param name="bitmap">System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param>
  223. /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param>
  224. public void Save(Bitmap bitmap, string writepath)
  225. {
  226. try
  227. {
  228. bitmap.Save(writepath, GetImageFormat(GetExtension(writepath)));
  229. bitmap.Dispose();
  230. }
  231. catch
  232. {
  233. throw new ArgumentException("图片保存错误");
  234. }
  235. }
  236. /// <summary>
  237. /// 保存: 对象到图片文件
  238. /// </summary>
  239. /// <param name="readpath">原图路径(包含完整路径,文件名及其扩展名): string</param>
  240. /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param>
  241. public void Save(string readpath, string writepath)
  242. {
  243. if (string.Compare(readpath, writepath) == 0)
  244. throw new ArgumentException("源图片与目标图片地址相同");
  245. try
  246. {
  247. Save(new Bitmap(readpath), writepath);
  248. }
  249. catch
  250. {
  251. throw new ArgumentException("图片读取错误");
  252. }
  253. }
  254. #endregion 普通保存结束
  255. #region 文字绘图保存开始
  256. #endregion 文字绘图保存结束
  257. #region 透明度调整保存开始
  258. /// <summary>
  259. /// 保存: 设置透明度的对象到图片文件
  260. /// </summary>
  261. /// <param name="sBitmap">图片 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param>
  262. /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param>
  263. /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param>
  264. public void SaveTransparence(Bitmap bitmap, float transparence, string writepath)
  265. {
  266. Save(SetTransparence(bitmap, transparence), writepath);
  267. }
  268. /// <summary>
  269. /// 保存: 设置透明度的象到图片文件
  270. /// </summary>
  271. /// <param name="readpath">原图路径(包含完整路径,文件名及其扩展名): string</param>
  272. /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param>
  273. /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param>
  274. public void SaveTransparence(string readpath, float transparence, string writepath)
  275. {
  276. Save(SetTransparence(readpath, transparence), writepath);
  277. }
  278. #endregion 透明度调整保存结束
  279. #region 水印图片保存开始
  280. /// <summary>
  281. /// 保存: 绘制水印的对象到图片文件
  282. /// </summary>
  283. /// <param name="sBitmap">原图 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param>
  284. /// <param name="wBitmap">水印 System.Drawing.Bitmap 对象: System.Drawing.Bitmap</param>
  285. /// <param name="position">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition : Uinatlex.ToolBox.ImageManager.WatermarkPosition</param>
  286. /// <param name="margin">水印边距: int</param>
  287. /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param>
  288. public void SaveWatermark(Bitmap sBitmap, Bitmap wBitmap, WatermarkPosition position, int margin, string writepath)
  289. {
  290. Save(CreateWatermark(sBitmap, wBitmap, position, margin), writepath);
  291. }
  292. /// <summary>
  293. /// 保存: 绘制水印的对象到图片文件
  294. /// </summary>
  295. /// <param name="readpath">图片路径(包含完整路径,文件名及其扩展名): string</param>
  296. /// <param name="watermarkpath">水印图片路径(包含完整路径,文件名及其扩展名): string</param>
  297. /// <param name="transparence">水印透明度(值越高透明度越低,范围在0.0f~1.0f之间): float</param>
  298. /// <param name="position">枚举 Uinatlex.ToolBox.ImageManager.WatermarkPosition : Uinatlex.ToolBox.ImageManager.WatermarkPosition</param>
  299. /// <param name="margin">水印边距: int</param>
  300. /// <param name="writepath">保存路径(包含完整路径,文件名及其扩展名): string</param>
  301. public void SaveWatermark(string readpath, string watermarkpath, float transparence, WatermarkPosition position, int margin, string writepath)
  302. {
  303. if (string.Compare(readpath, writepath) == 0)
  304. throw new ArgumentException("源图片与目标图片地址相同");
  305. if (transparence == 0.0f)
  306. Save(readpath, writepath);
  307. else if (transparence == 1.0f)
  308. SaveWatermark(new Bitmap(readpath), new Bitmap(watermarkpath), position, margin, writepath);
  309. else
  310. SaveWatermark(new Bitmap(readpath), SetTransparence(watermarkpath, transparence), position, margin, writepath);
  311. }
  312. #endregion 水印图片保存结束
  313. #region 图片切割保存开始
  314. #endregion 图片切割保存结束
  315. #region 图片缩放保存开始
  316. #endregion 图片缩放保存开始
  317. #endregion 保存图片到文件结束
  318. }
  319. }
  320. /*
  321. 调用很简单 im.SaveWatermark(原图地址, 水印地址, 透明度, 水印位置, 边距,保存位置);
  322. Uinatlex.ToolBox.ImageManager im = new Uinatlex.ToolBox.ImageManager();
  323. im.SaveWatermark(Server.MapPath("/原图.jpg"), Server.MapPath("/水印.jpg"), 0.5f, Uinatlex.ToolBox.ImageManager.WatermarkPosition.RigthBottom, 10, Server.MapPath("/原图.jpg"));
  324. */

在客户端页面中调用上面这个类

  1. protected void Page_Load(object sender, EventArgs e)
  2. {
  3. string newfileName = Server.MapPath("img/") + DateTime.Now.Millisecond + "" + DateTime.Now.Second + ".jpg";
  4. ImageManager im = new ImageManager();
  5. //调用很简单 im.SaveWatermark(原图地址, 水印地址, 透明度, 水印位置, 边距,保存到的位置);
  6. im.SaveWatermark(Server.MapPath("img/Chrysanthemum.jpg"), Server.MapPath("img/woshi.jpg"), 0.9f, ImageManager.WatermarkPosition.RigthBottom, 10, newfileName);
  7. }

总结

好了,以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作能带来一定的帮助,如果有疑问大家可以留言交流,谢谢大家对脚本之家的支持。

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