Question

在validate方法中删除重复的好方法是什么？

public bool Validate()
{  
    string directoryErrorMessage = "Directory does not exist";

    if(!CheckPathExists(_settingsView.InPath)) _settingsView.SetInPathError(directoryErrorMessage);
    if(!CheckPathExists(_settingsView.OutPath)) _settingsView.SetOutPathError(directoryErrorMessage);
    if(!CheckPathExists(_settingsView.ProcessedPath)) _settingsView.SetProcessedPathError(directoryErrorMessage);

    return CheckPathExists(_settingsView.InPath) && 
        CheckPathExists(_settingsView.OutPath) &&
        CheckPathExists(_settingsView.ProcessedPath);
}

private bool CheckPathExists(string path)
{
    return Directory.Exists(path);
}

Answer 1

您为每个路径调用两次CheckPathExists（），尝试只调用一次，将结果保存为布尔值，然后使用布尔变量值。

Answer 2

将每个检查存储在变量中，这样您只需检查一次，然后重复使用该变量。

public bool Validate()
{  
    const string directoryErrorMessage = "Directory does not exist";
    bool inPathExists = CheckPathExists(_settingsView.InPath);
    bool outPathExists = CheckPathExists(_settingsView.OutPath);
    bool processedPathExists = CheckPathExists(_settingsView.ProcessedPath);

    if(!inPathExists) _settingsView.SetInPathError(directoryErrorMessage);
    if(!outPathExists) _settingsView.SetOutPathError(directoryErrorMessage);
    if(!processedPathExists) _settingsView.SetProcessedPathError(directoryErrorMessage);

    return inPathExists && 
        outPathExists &&
        processedPathExists;
}

我不知道您是否对_settingsView类有控制权，但让它自己处理验证可能会更好。它可能可以验证何时设置路径并在此时设置相应的错误消息。然后在验证代码中，它只需要检查_settingsView对象的IsValid属性。

//to use the below class, your Validate method would change to
public bool Validate()
{
    return _settingsView.IsValid;
}

internal class SettingsView
{
    private const string DirectoryErrorMessage = "Directory does not exist";

    private string _inPath;
    private string _inPathError;
    private bool _inPathValid;

    private string _outPath;
    private string _outPathError;
    private bool _outPathValid;

    private string _processedPath;
    private string _processedPathError;
    private bool _processedPathValid;

    public string InPath
    {
        get
        {
            return _inPath;
        }
        set
        {
            _inPath = value;
            _inPathValid = Directory.Exists(_inPath);
            _inPathError = _inPathValid ? string.Empty : DirectoryErrorMessage;
        }
    }
    public string InPathError
    {
        get
        {
            return _inPathError ?? string.Empty;
        }
    }

    // Write similar code for Out and Processed paths
    public bool IsValid
    {
        get
        {
            return _inPathValid && _outPathValid && _processedPathValid;
        }
    }
}

Answer 3

在课堂上创建3个方法：

public bool Validate()
{  
   return  CheckInPath() &CheckOutPath()&CheckProcessedPath();
}

  public bool CheckInPath()
  {
       if(!CheckPathExists(_settingsView.InPath)) {
            _settingsView.SetInPathError(directoryErrorMessage);
             return false;
        }
        return true;
    }

     public bool CheckOutPath(string path)
     {
         if(!CheckPathExists(_settingsView.InPath)) {
               _settingsView.SetOutPathError(directoryErrorMessage);
               return false;
          }
          return true;
     }

      public bool CheckProcessedPath(string path)
      {
          if(!CheckPathExists(_settingsView.ProcessedPath)) {
              _settingsView.SetProcessedPathError(directoryErrorMessage);
               return false;
            }
            return true;
       }

从验证方法中删除重复项

3 个答案: