using System.Diagnostics;

namespace WinFormsApp3
{
    /// <summary>
    /// 截图预览诊断日志：exe 目录下 preview_debug.log。
    /// 挂起类问题光看界面定位不到，必须把每一步（含线程号）落到磁盘上。
    /// </summary>
    public static class PreviewLog
    {
        private static readonly object Gate = new();
        private static readonly string FilePath = Path.Combine(AppContext.BaseDirectory, "preview_debug.log");

        public static void Write(string message)
        {
            string line = $"{DateTime.Now:HH:mm:ss.fff} [T{Thread.CurrentThread.ManagedThreadId:D2}] {message}";
            try
            {
                lock (Gate) File.AppendAllText(FilePath, line + Environment.NewLine);
            }
            catch
            {
                // 日志写失败不影响功能
            }
        }
    }
}