.NET c#GDI绘图,绘制图片水印

窗口设计:

代码:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Drawing.Imaging;
namespace _05添加水印
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        string[] FileList;
        /// 

        /// 所有选中的图片的文件路径获取到
        /// 
        string dirFilePath;
        private void button1_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog()==DialogResult.OK)
            {
                listBox1.Items.Clear