如何用C#实现数据库连接的健康检查？代码怎么写？

using System;
using System.Data.SqlClient;

public class DatabaseHealthCheck
{
    private readonly string _connectionString;

    public DatabaseHealthCheck(string connectionString)
    {
        _connectionString = connectionString;
    }

    public bool IsHealthy()
    {
        try
        {
            using (var connection = new SqlConnection(_connectionString))
            {
                connection.Open();
                using (var command = new SqlCommand("SELECT 1", connection))
                {
                    var result = command.ExecuteScalar();
                    return Convert.ToInt32(result) == 1;
                }
            }
        }
        catch (SqlException)
        {
            return false;
        }
        catch (Exception)
        {
            return false;
        }
    }
}

// Program.cs (.NET 6+)
var builder = WebApplication.CreateBuilder(args);

// 添加健康检查服务
builder.Services.AddHealthChecks()
    .AddSqlServer(builder.Configuration.GetConnectionString("DefaultConnection"));

var app = builder.Build();

// 使用健康检查中间件
app.MapHealthChecks("/health");

app.Run();

using Microsoft.Extensions.Diagnostics.HealthChecks;
using System.Data.SqlClient;

public class CustomDatabaseHealthCheck : IHealthCheck
{
    private readonly string _connectionString;

    public CustomDatabaseHealthCheck(string connectionString)
    {
        _connectionString = connectionString;
    }

    public async Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context, CancellationToken cancellationToken = default)
    {
        try
        {
            using var connection = new SqlConnection(_connectionString);
            await connection.OpenAsync(cancellationToken);

            using var command = new SqlCommand("SELECT 1", connection);
            var result = await command.ExecuteScalarAsync(cancellationToken);

            if (Convert.ToInt32(result) == 1)
            {
                return HealthCheckResult.Healthy("数据库连接正常");
            }

            return HealthCheckResult.Unhealthy("数据库响应异常");
        }
        catch (Exception ex)
        {
            return HealthCheckResult.Unhealthy("数据库连接失败", ex);
        }
    }
}

builder.Services.AddHealthChecks()
    .AddCheck<CustomDatabaseHealthCheck>("database");