.Net图片文字水印帮助类
可定义水印位置、水印质量、以及水印透明度
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Drawing.Imaging;
using System.Drawing;
using System.IO;
namespace AutoHome.CommonHelper
{
public class WaterMark
{
/// <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 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 void AddImageSignPic(string imgPath, string filename, string watermarkFilename, int watermarkStatus, int quality, int watermarkTransparency)
{
if (!File.Exists(GetMapPath(imgPath)))
return;
byte[] _ImageBytes = File.ReadAllBytes(GetMapPath(imgPath));
Image img = Image.FromStream(new System.IO.MemoryStream(_ImageBytes));
filename = GetMapPath(filename);
if (watermarkFilename.StartsWith("/") == false)
watermarkFilename = "/" watermarkFilename;
watermarkFilename = GetMapPath(watermarkFilename);
if (!File.Exists(watermarkFilename))
return;
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;
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();
}
/// <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="fontname">字体</param>
/// <param name="fontsize">字体大小</param>
public static void AddImageSignText(string imgPath, string filename, string watermarkText, int watermarkStatus, int quality, string fontname, int fontsize)
{
byte[] _ImageBytes = File.ReadAllBytes(GetMapPath(imgPath));
Image img = Image.FromStream(new System.IO.MemoryStream(_ImageBytes));
filename = GetMapPath(filename);
Graphics g = Graphics.FromImage(img);
Font drawFont = new Font(fontname, fontsize, FontStyle.Regular, GraphicsUnit.Pixel);
SizeF crSize;
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(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();
}
#region 获得当前绝对路径
/// <summary>
/// 获得当前绝对路径
/// </summary>
/// <param name="strPath">指定的路径</param>
/// <returns>绝对路径</returns>
public static string GetMapPath(string strPath)
{
if (strPath.ToLower().StartsWith("http://"))
{
return strPath;
}
if (HttpContext.Current != null)
{
string path = System.Web.HttpContext.Current.Server.MapPath("/") strPath;
return path;
}
else //非web程序引用
{
strPath = strPath.Replace("/", "\\");
if (strPath.StartsWith("\\"))
{
strPath = strPath.Substring(strPath.IndexOf('\\', 1)).TrimStart('\\');
}
return System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, strPath);
}
}
#endregion
}
}
原文链接：.Net图片文字水印帮助类 可定义水印位置质量透明度