方法1，使用自带的画刷进行绘制水印
示例代码
public partial class Form1 : Form{public Form1(){InitializeComponent();}string photoPath=string.Empty;Bitmap image = null;private void button1_Click(object sender, EventArgs e) //选择照片{OpenFileDialog dialog = new OpenFileDialog(); //打开对话框dialog.Filter = "|*.jpg"; //打开文件过滤器if (dialog.ShowDialog() == DialogResult.OK){photoPath = dialog.FileName; //拿到用户选择文件的全路径pictureBox1.Image = System.Drawing.Image.FromFile(photoPath) ; //显示照片 }}private void button2_Click(object sender, EventArgs e) //添加水印{image = new Bitmap(photoPath);Graphics graphics = Graphics.FromImage(image);string watermarkText = "测试水印"+DateTime.Now;Font font = new Font("宋体", 12);Brush brush = new SolidBrush(Color.Red);Point position = new Point(10, 10); //显示的初始位置graphics.DrawString(watermarkText, font, brush, position);graphics.Dispose(); //释放资源pictureBox1.Image = image;}private void button3_Click(object sender, EventArgs e) //保存带水印照片{SaveFileDialog saveFileDialog = new SaveFileDialog(); //保存文件对话框saveFileDialog.Filter = "照片|*.jpg"; //保存的文件格式if (saveFileDialog.ShowDialog() == DialogResult.OK){string filePath = saveFileDialog.FileName; // 获取用户选择的文件全路径image.Save(filePath);}}}前台界面
