asp.net添加水印图片

下面是需要加水印的aspx

View Code
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>

    <script type="text/javascript" src="../js/jquery-1.4.2.js"></script>

    <script src="http://www.cnblogs.com/js/jquery-1.6.2.min.js" type="text/javascript"></script>

    <script src="http://www.cnblogs.com/js/jquery-ui-1.8.2.custom.min.js" type="text/javascript"></script>

    <script type="text/javascript">
        $(function() {
            $("#fly").draggable({ cursor: 'move', containment: "#largin", revert: false,
                stop: function() {
                    $("#<%=HiddenField1.ClientID %>").val($("#fly").css("left"));
                    $("#<%=HiddenField2.ClientID %>").val($("#fly").css("top"));
                }
            });
            $("#btndown").click(function() {
                var i = parseFloat($("#<%=HiddenField3.ClientID %>").val()) - parseFloat(0.10);
                $("#<%=HiddenField3.ClientID %>").val(i);
                $("#fly").fadeTo(1, i);
            });
            $("#btnup").click(function() {
                var i = parseFloat($("#<%=HiddenField3.ClientID %>").val()) + parseFloat(0.10);
                if (i >= "1") {
                    i = "1";
                }
                $("#<%=HiddenField3.ClientID %>").val(i);
                $("#fly").fadeTo(1, i);
            });

        });
    </script>

</head>
<body style="margin: 0px auto">
    <form runat="server">
    <div style="text-align: center;">
        <div style="position: relative;  800px; height: 800px; border: 1px solid">
            <%if (imgModel.WaterImg != null && imgModel.WaterImg != "")
              { %>
            <img src="http://www.cnblogs.com/Img/watermid/<%=imgModel.WaterImg %>" alt="" style="position: absolute;
                border: 1px solid" id="fly" />
            <%} %>
            <img src="http://www.cnblogs.com/Img/big/<%=imgModel.ImgName %>" alt="" id="largin" style="border: 1px solid" />
        </div>
        <div>
            <asp:FileUpload ID="FileUpload1" runat="server" />&nbsp;&nbsp;&nbsp;<asp:Button ID="Button1"
                runat="server" Text="上传" OnClick="Button1_Click" Width="55px" />
                 <%if (imgModel.WaterImg != null && imgModel.WaterImg != "")
          { %>
       
            透明度:<input type="button" id="btndown" value="-" /><input type="button" id="btnup"
                value="+" />
            <asp:Button ID="BtnUp" runat="server" Text="确定" OnClick="BtnUp_Click" Width="59px" />
            <%} %>
        </div>
       
     
        <asp:HiddenField ID="HiddenField1" runat="server" />
        <asp:HiddenField ID="HiddenField2" runat="server" />
        <asp:HiddenField ID="HiddenField3" runat="server" Value="1.00" />
        
    </div>
    </form>
</body>
</html>

aspx.cs

View Code
public partial class Water : System.Web.UI.Page
    {
        Cw100.BLL.CW100_Image imgbll = new Cw100.BLL.CW100_Image();
        public Cw100.Model.CW100_Image imgModel = new Cw100.Model.CW100_Image();
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                GetImgId();
            }
        }
        private void GetImgId()
        {
            if (Request.QueryString["imgid"] != null)
            {
                string imgid = Request.QueryString["imgid"];

                imgModel = imgbll.GetModel(Convert.ToInt32(imgid));
            }
        }

        protected void BtnUp_Click(object sender, EventArgs e)
        {
            string imgid = Request.QueryString["imgid"];
            string left1 = HiddenField1.Value;
            int i =left1.LastIndexOf( "px");
            string left= left1.Substring(0,i);

            string top1 = HiddenField2.Value;
            int j = top1.LastIndexOf("px");
            string top = top1.Substring(0,j);

            string color = HiddenField3.Value;
            if (Upload(imgid,left,top,color) == true)
            {
                Response.Redirect("PicIndex.aspx");
            }
        }
        protected bool Upload(string imgid,string left,string top,string color)
        {
            bool succ = false;
            imgModel = imgbll.GetModel(Convert.ToInt32(imgid));
          
                //删除原来的图片
                if (File.Exists(System.Web.HttpContext.Current.Server.MapPath("http://www.cnblogs.com/Img/big/" + imgModel.WaterImgName + "")))
                {
                    File.Delete(System.Web.HttpContext.Current.Server.MapPath("http://www.cnblogs.com/Img/big/" + imgModel.WaterImgName + ""));
                }
      string name= Cw100_web.background.PicSpace.WaterImageManage.DrawImage(imgModel.ImgName, imgModel.WaterImg, float.Parse(color),left,top, "~/Img/mid/","~/Img/watermid/","~/Img/big/");
              imgModel.WaterImgName = name;
              if (imgbll.Update(imgModel) == true)
              {
                  succ = true;
              }
            
            return succ;
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string imgid = Request.QueryString["imgid"];
            imgModel = imgbll.GetModel(Convert.ToInt32(imgid));
            string filename = string.Empty;
            if (FileUpload1.HasFile != false)
            {
                filename = FileUpload1.FileName;
                int i = filename.LastIndexOf(".");
                string after = filename.Substring(i, filename.Length - i);
                if (after != ".jpg" && after != ".GPG" && after != ".gif" && after != ".GIF" && after != ".png" && after != ".PNG" && after != ".jpeg" && after != ".JPEG")
                {
                    System.Web.HttpContext.Current.Response.Write("<script language='javascript'>alert('请选择正确格式的图片文件')</script>");
                }
                else
                {
                    FileUpload1.SaveAs(System.Web.HttpContext.Current.Server.MapPath("http://www.cnblogs.com/Img/watermid/" + filename + ""));
                    imgModel.WaterImg = filename;
                    if (imgbll.Update(imgModel) == true)
                    {
                        Response.Redirect("Water.aspx?imgid=" + imgid);
                    }
                }
            }
            else
            {
                ClientScript.RegisterStartupScript(this.GetType(), "", "alert('请选择上传图片');", true);
            }

        }
    }
}

waterPic类

View Code
public enum ImagePosition
    {
        LeftTop,        //左上
        LeftBottom,    //左下
        RightTop,       //右上
        RigthBottom, //右下
        TopMiddle,     //顶部居中
        BottomMiddle, //底部居中
        Center           //中心
    }
    public  class WaterImageManage
    {
        /// <summary>
        /// 生成一个新的水印图片制作实例
        /// </summary>
        public WaterImageManage()
        {
            //
            // TODO: Add constructor logic here
            //
        }

        /// <summary>
        /// 添加图片水印
        /// </summary>
        /// <param name="sourcePicture">源图片文件名</param>
        /// <param name="waterImage">水印图片文件名</param>
        /// <param name="alpha">透明度(0.1-1.0数值越小透明度越高)</param>
        /// <param name="position">位置</param>
        /// <param name="PicturePath" >图片的路径</param>
        /// <returns>返回生成于指定文件夹下的水印文件名</returns>
        public static string DrawImage(string sourcePicture, string waterImage, float alpha,string left,string top,string PicturePath,string NewpicPath,string BigwaterPath)
        {
            //
            // 判断参数是否有效
            //
            if (sourcePicture == string.Empty || waterImage == string.Empty || alpha == 0.0 || PicturePath == string.Empty)
            {
                return sourcePicture;
            }

            //
            // 源图片,水印图片全路径
            //
           // 原图片路径
            string sourcePictureName = PicturePath + sourcePicture;
            string sourcepictureName2 = BigwaterPath + sourcePicture;
           
            //水印图片路径
            string waterPictureName = NewpicPath + waterImage;

            string fileSourceExtension = System.IO.Path.GetExtension(sourcePictureName).ToLower();
            string fileWaterExtension = System.IO.Path.GetExtension(waterPictureName).ToLower();
            //
            // 判断文件是否存在,以及类型是否正确
            //

      if (System.IO.File.Exists(System.Web.HttpContext.Current.Server.MapPath(sourcePictureName)) == false ||System.IO.File.Exists(System.Web.HttpContext.Current.Server.MapPath(waterPictureName))==false || (fileSourceExtension != ".gif" &&fileSourceExtension != ".jpg" &&  fileSourceExtension != ".png") || ( fileWaterExtension != ".gif" && fileWaterExtension != ".jpg" && fileWaterExtension != ".png")
                )
            {
                return sourcePicture;
            }

            //
            // 目标图片名称及全路径
            //
            string targetImage = sourcepictureName2.Replace(System.IO.Path.GetExtension(sourcepictureName2), "") + "_1101.jpg";

            //
            // 将需要加上水印的图片装载到Image对象中
            //
            System.Drawing.Image imgPhoto = System.Drawing.Image.FromFile(System.Web.HttpContext.Current.Server.MapPath(sourcePictureName));
            //
            // 确定其长宽
            //
            int phWidth = imgPhoto.Width;
            int phHeight = imgPhoto.Height;

            //
            // 封装 GDI+ 位图,此位图由图形图像及其属性的像素数据组成。
            //
            Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);

            //
            // 设定分辨率
            // 
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

            //
            // 定义一个绘图画面用来装载位图
            //
            Graphics grPhoto = Graphics.FromImage(bmPhoto);

            //
            //同样,由于水印是图片,我们也需要定义一个Image来装载它
            //
            System.Drawing.Image imgWatermark = new Bitmap(System.Web.HttpContext.Current.Server.MapPath(waterPictureName));

            //
            // 获取水印图片的高度和宽度
            //
            int wmWidth = imgWatermark.Width;
            int wmHeight = imgWatermark.Height;

            //SmoothingMode:指定是否将平滑处理(消除锯齿)应用于直线、曲线和已填充区域的边缘。
            // 成员名称   说明 
            // AntiAlias      指定消除锯齿的呈现。 
            // Default        指定不消除锯齿。 
            // HighQuality 指定高质量、低速度呈现。 
            // HighSpeed   指定高速度、低质量呈现。 
            // Invalid        指定一个无效模式。 
            // None          指定不消除锯齿。 
            grPhoto.SmoothingMode = SmoothingMode.AntiAlias;

            //
            // 第一次描绘,将我们的底图描绘在绘图画面上
            //
            grPhoto.DrawImage(imgPhoto,
                                        new Rectangle(0, 0, phWidth, phHeight),
                                        0,
                                        0,
                                        phWidth,
                                        phHeight,
                                        GraphicsUnit.Pixel);

            //
            // 与底图一样,我们需要一个位图来装载水印图片。并设定其分辨率
            //
            Bitmap bmWatermark = new Bitmap(bmPhoto);
            bmWatermark.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

            //
            // 继续,将水印图片装载到一个绘图画面grWatermark
            //
            Graphics grWatermark = Graphics.FromImage(bmWatermark);

            //
            //ImageAttributes 对象包含有关在呈现时如何操作位图和图元文件颜色的信息。
            //       
            ImageAttributes imageAttributes = new ImageAttributes();

            //
            //Colormap: 定义转换颜色的映射
            //
            ColorMap colorMap = new ColorMap();

            //
            //我的水印图被定义成拥有绿色背景色的图片被替换成透明
            //
            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[][] colorMatrixElements = { 
           new float[] {1.0f, 0.0f, 0.0f, 0.0f, 0.0f}, // red红色
           new float[] {0.0f, 1.0f, 0.0f, 0.0f, 0.0f}, //green绿色
           new float[] {0.0f, 0.0f, 1.0f, 0.0f, 0.0f}, //blue蓝色       
           new float[] {0.0f, 0.0f, 0.0f, alpha, 0.0f}, //透明度     
           new float[] {0.0f, 0.0f, 0.0f, 0.0f, 1.0f}};//

            // ColorMatrix:定义包含 RGBA 空间坐标的 5 x 5 矩阵。
            // ImageAttributes 类的若干方法通过使用颜色矩阵调整图像颜色。
            ColorMatrix wmColorMatrix = new ColorMatrix(colorMatrixElements);


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

            //
            //上面设置完颜色,下面开始设置位置
            //
            int xPosOfWm=Convert.ToInt32(left);
            int yPosOfWm=Convert.ToInt32(top);
            //
            // 第二次绘图,把水印印上去
            //
            grWatermark.DrawImage(imgWatermark,
             new Rectangle(xPosOfWm,
                                 yPosOfWm,
                                 wmWidth,
                                 wmHeight),
                                 0,
                                 0,
                                 wmWidth,
                                 wmHeight,
                                 GraphicsUnit.Pixel,
                                 imageAttributes);


            imgPhoto = bmWatermark;
            grPhoto.Dispose();
            grWatermark.Dispose();

            //
            // 保存文件到服务器的文件夹里面
            //
            imgPhoto.Save(System.Web.HttpContext.Current.Server.MapPath(targetImage), ImageFormat.Jpeg);
            imgPhoto.Dispose();
            imgWatermark.Dispose();
            return targetImage.Replace(BigwaterPath, "");
        }

        /// <summary>
        /// 在图片上添加水印文字
        /// </summary>
        /// <param name="sourcePicture">源图片文件(文件名,不包括路径)</param>
        /// <param name="waterWords">需要添加到图片上的文字</param>
        /// <param name="alpha">透明度</param>
        /// <param name="position">位置</param>
        /// <param name="PicturePath">文件路径</param>
        /// <returns></returns>
        public static string DrawWords(string sourcePicture,string waterWords,float alpha, ImagePosition position, string PicturePath)
        {
            //
            // 判断参数是否有效
            //
            if (sourcePicture == string.Empty || waterWords == string.Empty || alpha == 0.0 || PicturePath == string.Empty)
            {
                return sourcePicture;
            }

            //
            // 源图片全路径
            //
            if (PicturePath.Substring(PicturePath.Length - 1, 1) != "\\")
                PicturePath += "\\";
            string sourcePictureName = PicturePath + sourcePicture;
            string fileExtension = System.IO.Path.GetExtension(sourcePictureName).ToLower();

            //
            // 判断文件是否存在,以及文件名是否正确
            //
            if (System.IO.File.Exists(System.Web.HttpContext.Current.Server.MapPath(sourcePictureName)) == false || (
                fileExtension != ".gif" &&
                fileExtension != ".jpg" &&
                fileExtension != ".png"))
            {
                return sourcePicture;
            }

            //
            // 目标图片名称及全路径
            //
            string targetImage = sourcePictureName.Replace(System.IO.Path.GetExtension(sourcePictureName), "") + "_0703.jpg";

            //创建一个图片对象用来装载要被添加水印的图片
            Image imgPhoto = Image.FromFile(System.Web.HttpContext.Current.Server.MapPath(sourcePictureName));

            //获取图片的宽和高
            int phWidth = imgPhoto.Width;
            int phHeight = imgPhoto.Height;

            //
            //建立一个bitmap,和我们需要加水印的图片一样大小
            Bitmap bmPhoto = new Bitmap(phWidth, phHeight, PixelFormat.Format24bppRgb);

            //SetResolution:设置此 Bitmap 的分辨率
            //这里直接将我们需要添加水印的图片的分辨率赋给了bitmap
            bmPhoto.SetResolution(imgPhoto.HorizontalResolution, imgPhoto.VerticalResolution);

            //Graphics:封装一个 GDI+ 绘图图面。
            Graphics grPhoto = Graphics.FromImage(bmPhoto);

            //设置图形的品质
            grPhoto.SmoothingMode = SmoothingMode.AntiAlias;

            //将我们要添加水印的图片按照原始大小描绘(复制)到图形中
            grPhoto.DrawImage(
             imgPhoto,                                           //   要添加水印的图片
             new Rectangle(0, 0, phWidth, phHeight), // 根据要添加的水印图片的宽和高
             0,                                                     // X方向从0点开始描绘
             0,                                                     // Y方向 
             phWidth,                                            // X方向描绘长度
             phHeight,                                           // Y方向描绘长度
             GraphicsUnit.Pixel);                              // 描绘的单位,这里用的是像素

            //根据图片的大小我们来确定添加上去的文字的大小
            //在这里我们定义一个数组来确定
            int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 };

            //字体
            Font crFont = null;
            //矩形的宽度和高度,SizeF有三个属性,分别为Height高,width宽,IsEmpty是否为空
            SizeF crSize = new SizeF();

            //利用一个循环语句来选择我们要添加文字的型号
            //直到它的长度比图片的宽度小
            for (int i = 0; i < 7; i++)
            {
                crFont = new Font("arial", sizes[i], FontStyle.Bold);

                //测量用指定的 Font 对象绘制并用指定的 StringFormat 对象格式化的指定字符串。
                crSize = grPhoto.MeasureString(waterWords, crFont);

                // ushort 关键字表示一种整数数据类型
                if ((ushort)crSize.Width < (ushort)phWidth)
                    break;
            }

            //截边5%的距离,定义文字显示(由于不同的图片显示的高和宽不同,所以按百分比截取)
            int yPixlesFromBottom = (int)(phHeight * .05);

            //定义在图片上文字的位置
            float wmHeight = crSize.Height;
            float wmWidth = crSize.Width;

            float xPosOfWm;
            float yPosOfWm;

            switch (position)
            {
                case ImagePosition.BottomMiddle:
                    xPosOfWm = phWidth / 2;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
                case ImagePosition.Center:
                    xPosOfWm = phWidth / 2;
                    yPosOfWm = phHeight / 2;
                    break;
                case ImagePosition.LeftBottom:
                    xPosOfWm = wmWidth;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
                case ImagePosition.LeftTop:
                    xPosOfWm = wmWidth / 2;
                    yPosOfWm = wmHeight / 2;
                    break;
                case ImagePosition.RightTop:
                    xPosOfWm = phWidth - wmWidth - 10;
                    yPosOfWm = wmHeight;
                    break;
                case ImagePosition.RigthBottom:
                    xPosOfWm = phWidth - wmWidth - 10;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
                case ImagePosition.TopMiddle:
                    xPosOfWm = phWidth / 2;
                    yPosOfWm = wmWidth;
                    break;
                default:
                    xPosOfWm = wmWidth;
                    yPosOfWm = phHeight - wmHeight - 10;
                    break;
            }

            //封装文本布局信息(如对齐、文字方向和 Tab 停靠位),显示操作(如省略号插入和国家标准 (National) 数字替换)和 OpenType 功能。
            StringFormat StrFormat = new StringFormat();

            //定义需要印的文字居中对齐
            StrFormat.Alignment = StringAlignment.Center;

            //SolidBrush:定义单色画笔。画笔用于填充图形形状,如矩形、椭圆、扇形、多边形和封闭路径。
            //这个画笔为描绘阴影的画笔,呈灰色
            int m_alpha = Convert.ToInt32(256 * alpha);
            SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(m_alpha, 0, 0, 0));

            //描绘文字信息,这个图层向右和向下偏移一个像素,表示阴影效果
            //DrawString 在指定矩形并且用指定的 Brush 和 Font 对象绘制指定的文本字符串。
            grPhoto.DrawString(waterWords,                                    //string of text
                                       crFont,                                         //font
                                       semiTransBrush2,                            //Brush
                                       new PointF(xPosOfWm + 1, yPosOfWm + 1), //Position
                                       StrFormat);

            //从四个 ARGB 分量(alpha、红色、绿色和蓝色)值创建 Color 结构,这里设置透明度为153
            //这个画笔为描绘正式文字的笔刷,呈白色
            SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));

            //第二次绘制这个图形,建立在第一次描绘的基础上
            grPhoto.DrawString(waterWords,                 //string of text
                                       crFont,                                   //font
                                       semiTransBrush,                           //Brush
                                       new PointF(xPosOfWm, yPosOfWm), //Position
                                       StrFormat);

            //imgPhoto是我们建立的用来装载最终图形的Image对象
            //bmPhoto是我们用来制作图形的容器,为Bitmap对象
            imgPhoto = bmPhoto;
            //释放资源,将定义的Graphics实例grPhoto释放,grPhoto功德圆满
            grPhoto.Dispose();

            //将grPhoto保存
            imgPhoto.Save(System.Web.HttpContext.Current.Server.MapPath(targetImage), ImageFormat.Jpeg);
            imgPhoto.Dispose();

            return targetImage.Replace(PicturePath, "");
        }
    }

    /// <summary>
    /// 装载水印图片的相关信息
    /// </summary>
    public class WaterImage
    {
        public WaterImage()
        {

        }

        private string m_sourcePicture;
        /// <summary>
        /// 源图片地址名字(带后缀)
        /// </summary>
        public string SourcePicture
        {
            get { return m_sourcePicture; }
            set { m_sourcePicture = value; }
        }

        private string m_waterImager;
        /// <summary>
        /// 水印图片名字(带后缀)
        /// </summary>
        public string WaterPicture
        {
            get { return m_waterImager; }
            set { m_waterImager = value; }
        }

        private float m_alpha;
        /// <summary>
        /// 水印图片文字的透明度
        /// </summary>
        public float Alpha
        {
            get { return m_alpha; }
            set { m_alpha = value; }
        }

        private ImagePosition m_postition;
        /// <summary>
        /// 水印图片或文字在图片中的位置
        /// </summary>
        public ImagePosition Position
        {
            get { return m_postition; }
            set { m_postition = value; }
        }

        private string m_words;
        /// <summary>
        /// 水印文字的内容
        /// </summary>
        public string Words
        {
            get { return m_words; }
            set { m_words = value; }
        }

    }

效果如图:

 能够对水印图片进行移动和颜色的渐变

原文地址:https://www.cnblogs.com/1003487863qq/p/2881777.html