c#WinForm給圖片加文字水印

設計界面：

cs:

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 練習
{
    public partial class Form6 : Form
    {
        public Form6()
        {
            InitializeComponent();
        }

        private void Form6_Load(object sender, EventArgs e)
        {
            pictureBox1.BorderStyle = BorderStyle.FixedSingle;
            pictureBox2.BorderStyle = BorderStyle.FixedSingle;
            pictureBox3.BorderStyle = BorderStyle.FixedSingle;

        }
        string[] FileList;
        string dirFilepath;
        private void button1_Click(object sender, EventArgs e)
        {
            if (openFileDialog1.ShowDialog()==DialogResult.OK)
            {
                FileList = openFileDialog1.FileNames;//文件名          
                dirFilepath = FileList[0].ToString().Remove(FileList[0].ToString().LastIndexOf("\\"));
                for (int i = 0; i < FileList.Length; i++)
                {
                    string imgpath = FileList[i].ToString();
                    FileInfo info = new FileInfo(imgpath);
                    if (info.Extension.ToLower()==".png"||info.Extension.ToLower()==".jpg"||info.Extension.ToLower()==".jpeg"||info.Extension.ToLower()==".gif")
                    {
                        textBox1.Text = info.Name;//獲取點擊的照片的名字
                    }
                    else
                    {
                        MessageBox.Show("選擇類型有誤！請重新選擇");
                    }
                }
                
            }
            string filepath = openFileDialog1.FileName;//獲取其選擇的照片的名字
            pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;//拉伸填充
            pictureBox1.ImageLocation = filepath;//展示圖片
        }


        FontFamily fontFamily = null;
        FontStyle fontStyle = FontStyle.Regular;//設置字體格式
        float size = 10;//字體大小
        Color color = Color.Black;//字體顏色
        bool x;
            
        private void button2_Click(object sender, EventArgs e)
        {
            if (pictureBox1.Image == null)
            {
                x = true;
                MessageBox.Show("請先選擇照片！");
            }
            else 
            {
                
            fontDialog1.ShowHelp = false;//去掉幫助按鈕 
            fontDialog1.ShowColor = true;//進行顏色選擇
            if (fontDialog1.ShowDialog()==DialogResult.OK)
            {
                fontFamily = fontDialog1.Font.FontFamily;//應用字體
                fontStyle = fontDialog1.Font.Style;//字體邊框
                size = fontDialog1.Font.Size;//字體大小
                color = fontDialog1.Color;//顏色
                AddFontWaterMark("",0);
            }
            }
            
        }
        string watermark = "";
        Font font;
        Brush Brush;
      
        private void AddFontWaterMark(string imgName,int i) 
        {
            //設置水印文字
            Brush = new SolidBrush(color);//顏色爲選中的顏色
            watermark = textBox2.Text.Trim();//移除空白
            //創建預覽圖片
            Bitmap bitmap = new Bitmap(200,50);//定義初始大小
            Graphics graphics = Graphics.FromImage(bitmap);//選擇繪製的圖
            graphics.Clear(Color.Wheat);//背景顏色
            font = new Font("楷體",size,fontStyle);//大小 顏色 字體
            SizeF maxsize = graphics.MeasureString(watermark,font);//繪圖大小
            Width = (int)maxsize.Width;
            Height = (int)maxsize.Height;
            graphics.DrawString(watermark,font,Brush,0,0);//樣式大小位置
            pictureBox2.Image = bitmap;//展示圖片
            pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;//填充拉伸
            if (i==1)
            {
                string fullpath = dirFilepath + "\\" + imgName;//創建添加水印的照片
                Bitmap bitmap1 = new Bitmap(Image.FromFile(fullpath));
                Graphics graphics1 = Graphics.FromImage(bitmap1);//重新繪圖
                graphics1.DrawString(watermark,font,Brush,100,100);//顏色位置都不變
                pictureBox3.Image = bitmap1;
                pictureBox3.SizeMode = PictureBoxSizeMode.StretchImage;
                FileInfo file = new FileInfo(fullpath);//路徑
                string h = file.Extension;//獲取擴展名
                //判斷擴展名是否一致
                if (h.ToLower()==".jpg"||h.ToLower()==".jpeg")
                {
                    bitmap1.Save(txtNewPath.Text+"\\_"+file.Name,ImageFormat.Jpeg);//保存至選擇的路徑並顯示名字

                }
                else if (h.ToLower()==".png")
                {
                    bitmap1.Save(txtNewPath.Text+"\\_"+file.Name,ImageFormat.Png);
                }
            }

        }

        private void button5_Click(object sender, EventArgs e)
        {
            if (folderBrowserDialog1.ShowDialog()==DialogResult.OK)
            {
                txtNewPath.Text = folderBrowserDialog1.SelectedPath;//顯示選擇路徑
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            if (txtNewPath.Text!=""&&textBox2.Text!=""&&pictureBox1.Image!=null)
            {
                AddFontWaterMark(textBox1.Text,1);
                MessageBox.Show("添加成功");
            }
            else
            {
                MessageBox.Show("請選擇路徑！或檢差原圖是否存在！");
            }
            
        }
    }
}