C#实现给图片添加文字水印的示例代码

public void AddWaterText(string oldpath, string text, string newpath, object point, System.Drawing.Font font, System.Drawing.Color color, float rotate = 0.0f, int textWidth = 1,int textHeight=1, int repeatD=0)
		{
			
			try
			{
				FileStream fs = new FileStream(oldpath, FileMode.Open);
				BinaryReader br = new BinaryReader(fs);
				byte[] bytes = br.ReadBytes((int)fs.Length);
				br.Close();
				fs.Close();
				MemoryStream ms = new MemoryStream(bytes);
 
				System.Drawing.Image imgPhoto = System.Drawing.Image.FromStream(ms);
				int imgPhotoWidth = imgPhoto.Width;
				int imgPhotoHeight = imgPhoto.Height;
 
				Bitmap bmPhoto = new Bitmap(imgPhotoWidth, imgPhotoHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
 
				bmPhoto.SetResolution(72, 72);
				Graphics gbmPhoto = Graphics.FromImage(bmPhoto);
				gbmPhoto.Clear(Color.FromName("white"));
				gbmPhoto.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
				gbmPhoto.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
				gbmPhoto.DrawImage(imgPhoto, new Rectangle(0, 0, imgPhotoWidth, imgPhotoHeight), 0, 0, imgPhotoWidth, imgPhotoHeight, GraphicsUnit.Pixel);
				System.Drawing.SizeF crSize = new SizeF();
				crSize = gbmPhoto.MeasureString(text, font);
				float y = imgPhotoHeight - crSize.Height;
				float x = imgPhotoWidth - crSize.Width;
 
				System.Drawing.StringFormat StrFormat = new System.Drawing.StringFormat();
				StrFormat.Alignment = System.Drawing.StringAlignment.Center;
 
				if(point!=null)
				{
					System.Drawing.Point newpos=((System.Drawing.Point)point);
					x=newpos.X;
					y=newpos.Y;
				}
 
 
				System.Drawing.SolidBrush semiTransBrush = new System.Drawing.SolidBrush(color);
				System.Drawing.Color.FromArgb(1,1,1,1);
                gbmPhoto.RotateTransform(rotate);
                if (repeatD == 0)
                {
                    gbmPhoto.DrawString(text, font, semiTransBrush, x, y);
                }
                else
                {
                    int xcount = imgPhotoWidth/textWidth+3;
                    int ycount = imgPhotoHeight/textHeight+3;
                    float ox = x;
                    for (int k = 0; k < ycount; k++)
                    {
                        for (int i = 0; i < xcount; i++)
                        {
                            for (int j = 0; j < xcount; j++)
                            {
 
                                gbmPhoto.DrawString(text, font, semiTransBrush, x, y);
                            }
                            x += textWidth+repeatD;
                        }
                        x = ox;
                        y += textHeight+repeatD;
                    }
                }
				bmPhoto.Save(newpath, System.Drawing.Imaging.ImageFormat.Jpeg);
				gbmPhoto.Dispose();
				imgPhoto.Dispose();
				bmPhoto.Dispose();
			}
			catch
			{               
				;               
			}
		}

//获取源图片文件路径
string tempfile=Request.PhysicalApplicationPath+"\\app_data\\test.jpg";
//设置文字位置
System.Drawing.Point point = new System.Drawing.Point();
point.X = -10;
point.Y = -100;
//设置字体类
System.Drawing.Font font = new System.Drawing.Font("微软雅黑", 19, System.Drawing.FontStyle.Bold);
//设置字体滤镜值 ，和RGB分量颜色
int alpha = 25; int r = 255; int g = 0; int b = 255;
System.Drawing.Color color = System.Drawing.Color.FromArgb(alpha, r, g, b);
 
 
float rotate=30.0f; // 旋转角度
int textWidth = 100; //文本预估宽度
int textHeight=30; //文本预估高度
int repeatD=100; // 多水印文本间距,则表示多水印输出
 
//添加水印文字
string text="版权所有";
AddWaterText(tempfile,text,tempfile, point, font, color,rotate,textWidth,textHeight,repeatD);
 
File.Delete(tempfile);  //删除释放文件，在些之前可执行显示操作，如获取base64编码