VisualStudio代码调试输出跟踪

Posted 2020-06-20 未将对象引用设置到对象的实例

class EFIntercepterLogging : DbCommandInterceptor
    {
        private readonly Stopwatch _stopwatch = new Stopwatch();
        public override void ScalarExecuting(System.Data.Common.DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
        {
            base.ScalarExecuting(command, interceptionContext);
            _stopwatch.Restart();
        }
        public override void ScalarExecuted(System.Data.Common.DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
        {
            _stopwatch.Stop();
            if (interceptionContext.Exception != null)
            {
                 Trace.TraceError ("Exception:{1} \r\n --> Error executing command: {0}", command.CommandText, interceptionContext.Exception.ToString());
            }
            else
            {
                Trace.TraceInformation("\r\n执行时间:{0} 毫秒\r\n-->ScalarExecuted.Command:{1}\r\n", _stopwatch.ElapsedMilliseconds, command.CommandText);
            }
            base.ScalarExecuted(command, interceptionContext);
        }
}