检查数据库C# windows窗体中的图像是否存在

using System;
using System.Data.SqlClient;

namespace ImageExistenceCheck
{
    public partial class Form1 : Form
    {
        private string connectionString = "YourConnectionString"; // 替换为实际的数据库连接字符串

        public Form1()
        {
            InitializeComponent();
        }

        private void btnCheckImage_Click(object sender, EventArgs e)
        {
            int imageId = int.Parse(txtImageId.Text); // 假设图像的唯一标识符存储在名为txtImageId的文本框中

            bool imageExists = CheckImageExistence(imageId);

            if (imageExists)
            {
                MessageBox.Show("图像存在于数据库中。");
            }
            else
            {
                MessageBox.Show("图像不存在于数据库中。");
            }
        }

        private bool CheckImageExistence(int imageId)
        {
            bool imageExists = false;

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();

                string query = "SELECT COUNT(*) FROM Images WHERE ImageId = @ImageId"; // 假设图像数据存储在名为Images的表中，且图像的唯一标识符列名为ImageId
                SqlCommand command = new SqlCommand(query, connection);
                command.Parameters.AddWithValue("@ImageId", imageId);

                int count = (int)command.ExecuteScalar();

                if (count > 0)
                {
                    imageExists = true;
                }
            }

            return imageExists;
        }
    }
}