C#图片加水印图片和文字

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Threading;
using System.Drawing.Imaging;

namespace WaterImage
{
    public partial class Form2 : Form
    {
        Image imgWeight;

        public Form2()
        {
            InitializeComponent();
        }
        /// <summary>
        /// 从数据库中加载二进制图片
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            string strSql = "Select Top 1 FileContent From Sys_FileSave";

            Byte[] byteImage = new Byte[0];

            byteImage = (Byte[])(DbHelperSQL.GetSingle(strSql));

            MemoryStream stmBLOBData = new MemoryStream(byteImage);

            imgWeight = Image.FromStream(stmBLOBData); pictureBox1.Image = imgWeight;
        }
        /// <summary>
        /// 在原图片基础上加载文字水印
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            Graphics GImage = Graphics.FromImage(imgWeight);

            addWatermarkText(GImage, "重量为60.00吨", "WM_BOTTOM_RIGHT", imgWeight.Width, imgWeight.Height);

            pictureBox1.Image = imgWeight;
        }
        /// <summary>
        /// 在原图片基础上加载图片水印
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            Graphics GImage = Graphics.FromImage(imgWeight);

            addWatermarkImage(GImage, @"C:\Documents and Settings\Administrator\桌面\Mark.png", "WM_TOP_LEFT", imgWeight.Width, imgWeight.Height);

            pictureBox1.Image = imgWeight;
        }
        /// <summary>
        /// 生成图片缩略图
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button4_Click(object sender, EventArgs e)
        {
            GreateMiniImage(@"C:\Documents and Settings\Administrator\桌面\Source.jpg", @"C:\Documents and Settings\Administrator\桌面\Small.png", 100, 200);
        }

        /// <summary>
        ///  加水印文字
        /// </summary>
        /// <param name="picture">imge 对象</param>
        /// <param name="_watermarkText">水印文字内容</param>
        /// <param name="_watermarkPosition">水印位置</param>
        /// <param name="_width">被加水印图片的宽</param>
        /// <param name="_height">被加水印图片的高</param>
        private void addWatermarkText(Graphics picture, string _watermarkText, string _watermarkPosition, int _width, int _height)
        {
            int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 };
            Font crFont = null;
            SizeF crSize = new SizeF();
            for (int i = 0; i < 7; i++)
            {
                crFont = new Font("arial", sizes[i], FontStyle.Bold);
                crSize = picture.MeasureString(_watermarkText, crFont);

                if ((ushort)crSize.Width < (ushort)_width)
                    break;
            }

            float xpos = 0;
            float ypos = 0;

            switch (_watermarkPosition)
            {
                case "WM_TOP_LEFT":
                    xpos = ((float)_width * (float).01) + (crSize.Width / 2);
                    ypos = (float)_height * (float).01;
                    break;
                case "WM_TOP_RIGHT":
                    xpos = ((float)_width * (float).99) - (crSize.Width / 2);
                    ypos = (float)_height * (float).01;
                    break;
                case "WM_BOTTOM_RIGHT":
                    xpos = ((float)_width * (float).99) - (crSize.Width / 2);
                    ypos = ((float)_height * (float).99) - crSize.Height;
                    break;
                case "WM_BOTTOM_LEFT":
                    xpos = ((float)_width * (float).01) + (crSize.Width / 2);
                    ypos = ((float)_height * (float).99) - crSize.Height;
                    break;
            }

            StringFormat StrFormat = new StringFormat();
            StrFormat.Alignment = StringAlignment.Center;

            SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0));
            picture.DrawString(_watermarkText, crFont, semiTransBrush2, xpos + 1, ypos + 1, StrFormat);

            SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));
            picture.DrawString(_watermarkText, crFont, semiTransBrush, xpos, ypos, StrFormat);


            semiTransBrush2.Dispose();
            semiTransBrush.Dispose();
        }

        /// <summary>
        ///  加水印图片
        /// </summary>
        /// <param name="picture">imge 对象</param>
        /// <param name="WaterMarkPicPath">水印图片的地址</param>
        /// <param name="_watermarkPosition">水印位置</param>
        /// <param name="_width">被加水印图片的宽</param>
        /// <param name="_height">被加水印图片的高</param>
        private void addWatermarkImage(Graphics picture, string WaterMarkPicPath, string _watermarkPosition, int _width, int _height)
        {
            Image watermark = new Bitmap(WaterMarkPicPath);

            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[][] 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,  0.3f, 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;
            int WatermarkWidth = 0;
            int WatermarkHeight = 0;
            double bl = 1d;
            //计算水印图片的比率
            //取背景的1/4宽度来比较
            if ((_width > watermark.Width * 4) && (_height > watermark.Height * 4))
            {
                bl = 1;
            }
            else if ((_width > watermark.Width * 4) && (_height < watermark.Height * 4))
            {
                bl = Convert.ToDouble(_height / 4) / Convert.ToDouble(watermark.Height);

            }
            else

                if ((_width < watermark.Width * 4) && (_height > watermark.Height * 4))
                {
                    bl = Convert.ToDouble(_width / 4) / Convert.ToDouble(watermark.Width);
                }
                else
                {
                    if ((_width * watermark.Height) > (_height * watermark.Width))
                    {
                        bl = Convert.ToDouble(_height / 4) / Convert.ToDouble(watermark.Height);

                    }
                    else
                    {
                        bl = Convert.ToDouble(_width / 4) / Convert.ToDouble(watermark.Width);

                    }

                }

            WatermarkWidth = Convert.ToInt32(watermark.Width * bl);
            WatermarkHeight = Convert.ToInt32(watermark.Height * bl);

            switch (_watermarkPosition)
            {
                case "WM_TOP_LEFT":
                    xpos = 10;
                    ypos = 10;
                    break;
                case "WM_TOP_RIGHT":
                    xpos = _width - WatermarkWidth - 10;
                    ypos = 10;
                    break;
                case "WM_BOTTOM_RIGHT":
                    xpos = _width - WatermarkWidth - 10;
                    ypos = _height - WatermarkHeight - 10;
                    break;
                case "WM_BOTTOM_LEFT":
                    xpos = 10;
                    ypos = _height - WatermarkHeight - 10;
                    break;
            }

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


            watermark.Dispose();
            imageAttributes.Dispose();
        }

        /// <summary>
        /// 生成缩略图
        /// </summary>
        /// <param name="oldpath">原图片地址</param>
        /// <param name="newpath">新图片地址</param>
        /// <param name="tWidth">缩略图的宽</param>
        /// <param name="tHeight">缩略图的高</param>
        private void GreateMiniImage(string oldpath, string newpath, int tWidth, int tHeight)
        {

            try
            {

                System.Drawing.Image image = System.Drawing.Image.FromFile(oldpath);
                double bl = 1d;
                if ((image.Width <= image.Height) && (tWidth >= tHeight))
                {
                    bl = Convert.ToDouble(image.Height) / Convert.ToDouble(tHeight);
                }
                else if ((image.Width > image.Height) && (tWidth < tHeight))
                {
                    bl = Convert.ToDouble(image.Width) / Convert.ToDouble(tWidth);

                }
                else

                    if ((image.Width <= image.Height) && (tWidth <= tHeight))
                    {
                        if (image.Height / tHeight >= image.Width / tWidth)
                        {
                            bl = Convert.ToDouble(image.Width) / Convert.ToDouble(tWidth);

                        }
                        else
                        {
                            bl = Convert.ToDouble(image.Height) / Convert.ToDouble(tHeight);
                        }
                    }
                    else
                    {
                        if (image.Height / tHeight >= image.Width / tWidth)
                        {
                            bl = Convert.ToDouble(image.Height) / Convert.ToDouble(tHeight);

                        }
                        else
                        {
                            bl = Convert.ToDouble(image.Width) / Convert.ToDouble(tWidth);

                        }

                    }


                Bitmap b = new Bitmap(image, Convert.ToInt32(image.Width / bl), Convert.ToInt32(image.Height / bl));

                b.Save(newpath);
                b.Dispose();
                image.Dispose();


            }
            catch
            {


            }

        }
    }
}