C#使用SaveFileDialog或FolderBrowserDialog保存图像文件

using System;
using System.Drawing;
using System.Windows.Forms;

namespace ImageSaveExample
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void saveButton_Click(object sender, EventArgs e)
        {
            SaveFileDialog saveFileDialog = new SaveFileDialog();
            saveFileDialog.Filter = "JPEG Image|*.jpg|PNG Image|*.png|BMP Image|*.bmp";
            saveFileDialog.Title = "Save Image";
            saveFileDialog.ShowDialog();

            if (saveFileDialog.FileName != "")
            {
                // 获取要保存的图像
                Image imageToSave = pictureBox.Image;

                // 获取文件扩展名
                string extension = System.IO.Path.GetExtension(saveFileDialog.FileName);

                // 根据文件扩展名选择图像格式
                ImageFormat imageFormat;
                switch (extension.ToLower())
                {
                    case ".jpg":
                        imageFormat = ImageFormat.Jpeg;
                        break;
                    case ".png":
                        imageFormat = ImageFormat.Png;
                        break;
                    case ".bmp":
                        imageFormat = ImageFormat.Bmp;
                        break;
                    default:
                        imageFormat = ImageFormat.Jpeg;
                        break;
                }

                // 保存图像文件
                imageToSave.Save(saveFileDialog.FileName, imageFormat);
            }
        }
    }
}