小编典典

什么时候使用try / catch块?

c#

我已经阅读完并理解了Try / Catch块的功能以及为什么使用它很重要。但是我一直坚持知道 何时/何
地使用它们。有什么建议吗?我将在下面发布我的代码示例,希望有人有时间为我的示例提出一些建议。

    public AMPFileEntity(string filename)
    {
        transferFileList tfl = new transferFileList();
        _AMPFlag = tfl.isAMPFile(filename);
        _requiresPGP = tfl.pgpRequired(filename);
        _filename = filename.ToUpper();
        _fullSourcePathAndFilename = ConfigurationSettings.AppSettings.Get("sourcePath") + _filename;
        _fullDestinationPathAndFilename = ConfigurationSettings.AppSettings.Get("FTPStagePath") + _filename;
        _hasBeenPGPdPathAndFilename = ConfigurationSettings.AppSettings.Get("originalsWhichHaveBeenPGPdPath");
    }


    public int processFile()
    {

        StringBuilder sb = new StringBuilder();
        sb.AppendLine(" ");
        sb.AppendLine("    --------------------------------");
        sb.AppendLine("     Filename: " + _filename);
        sb.AppendLine("     AMPFlag: " + _AMPFlag);
        sb.AppendLine("     Requires PGP: " + _requiresPGP);
        sb.AppendLine("    --------------------------------");
        sb.AppendLine(" ");

        string str = sb.ToString();
        UtilityLogger.LogToFile(str);
        if (_AMPFlag)
        {
            if (_requiresPGP == true)
            {
                encryptFile();
            }
            else
            {
                UtilityLogger.LogToFile("This file does not require encryption. Moving file to FTPStage directory.");
                if (File.Exists(_fullDestinationPathAndFilename))
                {
                    UtilityLogger.LogToFile(_fullDestinationPathAndFilename + " alreadyexists. Archiving that file.");
                    if (File.Exists(_fullDestinationPathAndFilename + "_archive"))
                    {
                        UtilityLogger.LogToFile(_fullDestinationPathAndFilename + "_archive already exists.  Overwriting it.");
                        File.Delete(_fullDestinationPathAndFilename + "_archive");
                    }
                    File.Move(_fullDestinationPathAndFilename, _fullDestinationPathAndFilename + "_archive");
                }
                File.Move(_fullSourcePathAndFilename, _fullDestinationPathAndFilename);
            }
        }
        else
        {
            UtilityLogger.LogToFile("This file is not an AMP transfer file. Skipping this file.");
        }

            return (0);
    }


    private int encryptFile()
    {

        UtilityLogger.LogToFile("This file requires encryption.  Starting encryption process.");


        // first check for an existing PGPd file in the destination dir.  if exists, archive it - otherwise this one won't save.  it doesn't overwrite.
        string pgpdFilename = _fullDestinationPathAndFilename + ".PGP";



        if(File.Exists(pgpdFilename))
        {
            UtilityLogger.LogToFile(pgpdFilename + " already exists in the FTPStage directory.  Archiving that file." );
            if(File.Exists(pgpdFilename + "_archive"))
            {
                UtilityLogger.LogToFile(pgpdFilename + "_archive already exists.  Overwriting it."); 
                File.Delete(pgpdFilename + "_archive");
            }
            File.Move(pgpdFilename, pgpdFilename + "_archive"); 
        }

        Process pProc = new Process();
        pProc.StartInfo.FileName = "pgp.exe";

        string strParams = @"--encrypt " + _fullSourcePathAndFilename + " --recipient infinata --output " + _fullDestinationPathAndFilename + ".PGP";

        UtilityLogger.LogToFile("Encrypting file.  Params: " + strParams);
        pProc.StartInfo.Arguments = strParams;
        pProc.StartInfo.UseShellExecute = false;
        pProc.StartInfo.RedirectStandardOutput = true;
        pProc.Start();
        pProc.WaitForExit();

        //now that it's been PGPd, save the orig in 'hasBeenPGPd' dir
        UtilityLogger.LogToFile("PGP encryption complete.  Moving original unencrypted file to " +  _hasBeenPGPdPathAndFilename); 
        if(File.Exists(_hasBeenPGPdPathAndFilename + _filename + "original_which_has_been_pgpd"))
        {
            UtilityLogger.LogToFile(_hasBeenPGPdPathAndFilename + _filename + "original_which_has_been_pgpd already exists.  Overwriting it.");
            File.Delete(_hasBeenPGPdPathAndFilename + _filename + "original_which_has_been_pgpd");
        }
            File.Move(_fullSourcePathAndFilename, _hasBeenPGPdPathAndFilename + _filename + "original_which_has_been_pgpd");

        return (0);

    }
}

}


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2020-05-19

共1个答案

小编典典

捕获异常的基本经验法则是, 当且仅当 您有有意义的处理 异常的方式 时,才 捕获异常

__如果只记录异常并将其抛出堆栈,则 不要 捕获异常。它没有意义,代码混乱。

难道 当你在你的代码的特定部分期待一个失败捕获异常,如果你有这方面的后备。

当然,总是会出现检查异常的情况,这要求您使用try / catch块,在这种情况下,您别无选择。即使有检查到的异常,也请确保您正确记录并尽可能干净地处理。

2020-05-19