/// <summary>

/// 图片加水印帮助类

/// </summary>

public class WaterMarkHelper

{

/// <summary>

/// 图片水印

/// </summary>

/// <param name="imgPath">服务器图片相对路径</param>

/// <param name="filename">保存文件名</param>

/// <param name="watermarkFilename">水印文件相对路径</param>

/// <param name="watermarkStatus">图片水印位置 0=不使用 1=左上 2=中上 3=右上 4=左中,5=居中,6=右中,7=左下,8=中下, 9=右下</param>

/// <param name="quality">附加水印图片质量,0-100</param>

/// <param name="watermarkTransparency">水印的透明度 1--10 10为不透明</param>

public static string AddImageWaterMark(string imgPath, string filename, string watermarkFilename, int watermarkStatus = 0, int quality = 100, int watermarkTransparency = 10)

{

if (!File.Exists(imgPath))

return "原图文件不存在";

if (!File.Exists(watermarkFilename))

return "水印文件不存在";

//如果保存文件不存在的就替换原图

if (string.IsNullOrEmpty(filename))

filename = imgPath;

try

{

byte[] _ImageBytes = File.ReadAllBytes(imgPath);

Image img = Image.FromStream(new MemoryStream(_ImageBytes));

Graphics g = Graphics.FromImage(img);

//设置高质量插值法

//g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

//设置高质量,低速度呈现平滑程度

//g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

Image watermark = new Bitmap(watermarkFilename);

if (watermark.Height >= img.Height || watermark.Width >= img.Width)

return "水印图片超过了原图大小";

ImageAttributes imageAttributes = new ImageAttributes();

ColorMap colorMap = new ColorMap();

colorMap.OldColor = Color.FromArgb(255, 0, 255, 0);

colorMap.NewColor = Color.FromArgb(0, 0, 0, 0);

ColorMap[] remapTable = { colorMap };

imageAttributes.SetRemapTable(remapTable, ColorAdjustType.Bitmap);

float transparency = 0.5F;

if (watermarkTransparency >= 1 && watermarkTransparency <= 10)

transparency = (watermarkTransparency / 10.0F);

float[][] colorMatrixElements = {

new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f},

new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f},

new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f},

new float[] {0.0f, 0.0f, 0.0f, transparency, 0.0f},

new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}

};

ColorMatrix colorMatrix = new ColorMatrix(colorMatrixElements);

imageAttributes.SetColorMatrix(colorMatrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);

int xpos = 0;

int ypos = 0;

switch (watermarkStatus)

{

case 1:

xpos = (int)(img.Width * (float).01);

ypos = (int)(img.Height * (float).01);

break;

case 2:

xpos = (int)((img.Width * (float).50) - (watermark.Width / 2));

ypos = (int)(img.Height * (float).01);

break;

case 3:

xpos = (int)((img.Width * (float).99) - (watermark.Width));

ypos = (int)(img.Height * (float).01);

break;

case 4:

xpos = (int)(img.Width * (float).01);

ypos = (int)((img.Height * (float).50) - (watermark.Height / 2));

break;

case 5:

xpos = (int)((img.Width * (float).50) - (watermark.Width / 2));

ypos = (int)((img.Height * (float).50) - (watermark.Height / 2));

break;

case 6:

xpos = (int)((img.Width * (float).99) - (watermark.Width));

ypos = (int)((img.Height * (float).50) - (watermark.Height / 2));

break;

case 7:

xpos = (int)(img.Width * (float).01);

ypos = (int)((img.Height * (float).99) - watermark.Height);

break;

case 8:

xpos = (int)((img.Width * (float).50) - (watermark.Width / 2));

ypos = (int)((img.Height * (float).99) - watermark.Height);

break;

case 9:

xpos = (int)((img.Width * (float).99) - (watermark.Width));

ypos = (int)((img.Height * (float).99) - watermark.Height);

break;

}

g.DrawImage(watermark, new Rectangle(xpos, ypos, watermark.Width, watermark.Height), 0, 0, watermark.Width, watermark.Height, GraphicsUnit.Pixel, imageAttributes);

ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();

ImageCodecInfo ici = null;

foreach (ImageCodecInfo codec in codecs)

{

if (codec.MimeType.IndexOf("jpeg") > -1)

ici = codec;

}

EncoderParameters encoderParams = new EncoderParameters();

long[] qualityParam = new long[1];

if (quality < 0 || quality > 100)

quality = 80;

qualityParam[0] = quality;

EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, qualityParam);

encoderParams.Param[0] = encoderParam;

if (ici != null)

img.Save(filename, ici, encoderParams);

else

img.Save(filename);

g.Dispose();

img.Dispose();

watermark.Dispose();

imageAttributes.Dispose();

return "水印添加成功";

}

catch (Exception ex)

{

return ex.Message;

}

}

/// <summary>

/// 文字水印

/// </summary>

/// <param name="imgPath">服务器图片相对路径</param>

/// <param name="filename">保存文件名</param>

/// <param name="watermarkText">水印文字</param>

/// <param name="watermarkStatus">图片水印位置 0=不使用 1=左上 2=中上 3=右上 4=左中 9=右下</param>

/// <param name="quality">附加水印图片质量,0-100</param>

/// <param name="fontsize">字体大小</param>

/// <param name="fontname">字体</param>

public static string AddTextWaterMark(string imgPath, string filename, string watermarkText, int watermarkStatus, int quality, int fontsize, string fontname = "微软雅黑")

{

if (!File.Exists(imgPath))

return "原图文件不存在";

if (string.IsNullOrEmpty(watermarkText))

return "水印文字不存在";

//如果保存文件不存在的就替换原图

if (string.IsNullOrEmpty(filename))

filename = imgPath;

try

{

byte[] _ImageBytes = File.ReadAllBytes(imgPath);

Image img = Image.FromStream(new MemoryStream(_ImageBytes));

Graphics g = Graphics.FromImage(img);

Font drawFont = new Font(fontname, fontsize, FontStyle.Regular, GraphicsUnit.Pixel);

SizeF crSize = g.MeasureString(watermarkText, drawFont);

float xpos = 0;

float ypos = 0;

switch (watermarkStatus)

{

case 1:

xpos = (float)img.Width * (float).01;

ypos = (float)img.Height * (float).01;

break;

case 2:

xpos = ((float)img.Width * (float).50) - (crSize.Width / 2);

ypos = (float)img.Height * (float).01;

break;

case 3:

xpos = ((float)img.Width * (float).99) - crSize.Width;

ypos = (float)img.Height * (float).01;

break;

case 4:

xpos = (float)img.Width * (float).01;

ypos = ((float)img.Height * (float).50) - (crSize.Height / 2);

break;

case 5:

xpos = ((float)img.Width * (float).50) - (crSize.Width / 2);

ypos = ((float)img.Height * (float).50) - (crSize.Height / 2);

break;

case 6:

xpos = ((float)img.Width * (float).99) - crSize.Width;

ypos = ((float)img.Height * (float).50) - (crSize.Height / 2);

break;

case 7:

xpos = (float)img.Width * (float).01;

ypos = ((float)img.Height * (float).99) - crSize.Height;

break;

case 8:

xpos = ((float)img.Width * (float).50) - (crSize.Width / 2);

ypos = ((float)img.Height * (float).99) - crSize.Height;

break;

case 9:

xpos = ((float)img.Width * (float).99) - crSize.Width;

ypos = ((float)img.Height * (float).99) - crSize.Height;

break;

}

g.DrawString(watermarkText, drawFont, new SolidBrush(Color.White), xpos + 1, ypos + 1);

g.DrawString(watermarkText, drawFont, new SolidBrush(Color.Black), xpos, ypos);

ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();

ImageCodecInfo ici = null;

foreach (ImageCodecInfo codec in codecs)

{

if (codec.MimeType.IndexOf("jpeg") > -1)

ici = codec;

}

EncoderParameters encoderParams = new EncoderParameters();

long[] qualityParam = new long[1];

if (quality < 0 || quality > 100)

quality = 80;

qualityParam[0] = quality;

EncoderParameter encoderParam = new EncoderParameter(Encoder.Quality, qualityParam);

encoderParams.Param[0] = encoderParam;

if (ici != null)

img.Save(filename, ici, encoderParams);

else

img.Save(filename);

g.Dispose();

img.Dispose();

return "水印文字添加成功";

}

catch (Exception ex)

{

return ex.Message;

}

}

/// <summary>

/// 在图片上添加平铺倾斜文字水印

/// </summary>

/// <param name="imgPath">源图片文件</param>

/// <param name="waterWords">需要添加到图片上的文字</param>

/// <returns></returns>

public static string AddTextWaterMark(string imgPath, string waterWords, int fontsize, int quality, string fontname = "微软雅黑")

{

if (!File.Exists(imgPath))

return "原图文件不存在";

if (string.IsNullOrEmpty(waterWords))

return "水印文字不存在";

try

{

Image img = Image.FromFile(imgPath);

// 获取图片的宽和高

int width = img.Width;

int height = img.Height;

Graphics g = Graphics.FromImage(img);

// 字体 字号 字体样式

Font drawFont = new Font(fontname, fontsize, FontStyle.Italic, GraphicsUnit.Pixel);

SizeF fontSize = g.MeasureString(waterWords, drawFont);

float xpos = 0;

float ypos = 0;

// 倾斜 -30°

g.RotateTransform(-30);

// 循环打印文字水印

for (int i = -width / 2; i < width * 1.5; i += 400)

{

xpos = i;

for (int j = -height / 2; j < height * 1.5; j += 240)

{

ypos = j;

g.DrawString(waterWords, drawFont, new SolidBrush(Color.FromArgb(50, 100, 100, 100)), xpos, ypos);

}

}

ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();

ImageCodecInfo ici = null;

foreach (ImageCodecInfo codec in codecs)

{

if (codec.MimeType.IndexOf("jpeg") > -1)

ici = codec;

}

EncoderParameters encoderParams = new EncoderParameters();

long[] qualityParam = new long[1];

// 图片质量：0 - 100

if (quality < 0 || quality > 100)

quality = 80;

qualityParam[0] = quality;

EncoderParameter encoderParam = new EncoderParameter(Encoder.Quality, qualityParam);

encoderParams.Param[0] = encoderParam;

Image newImage = new Bitmap((int)img.Width, (int)img.Height);

//新建一个画板

Graphics newG = Graphics.FromImage(newImage);

//设置质量

newG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;

newG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

//置背景色

newG.Clear(Color.White);

//画图

newG.DrawImage(img, new Rectangle(0, 0, newImage.Width, newImage.Height), new Rectangle(0, 0, img.Width, img.Height), GraphicsUnit.Pixel);

img.Dispose();

g.Dispose();

newImage.Save(imgPath, ImageFormat.Jpeg);

return imgPath;

}

catch (Exception ex)

{

return ex.Message;

}

}

}