Question

我使用工具箱菜单中的标准DataGridView。

我按事件cellEditEnd验证DataGridView中的每个单元格。它看起来像这样：

private void dataGrid_CellEditEnding(object sender,DataGridCellEditEndingEventArgs e)
{
     // Below I demonstrate pseudo code for brevity

     if(cell.name.value is not Number){
         print "Wrong cell value";
     }
}

因此，在另一种形式（WinForms）中，我有一些功能，可以从Excel文件导入数据并将其显示在DataGridView中。

我需要在插入每个单元格之前验证Excel数据。为此我可以使用事件CellValidation。但我不想重复我在dataGrid_CellEditEnding方法中使用的相同代码。

如何避免重复代码？

Answer 1

您可以查看责任设计模式链，您的代码将是可配置的，更面向对象，看起来像这样：

    public interface IHandler
    {
        void Handle(string value);
    }

    public abstract class CellRequestTemplate : IHandler
    {
        protected readonly IHandler _next;
        protected CellRequestTemplate(IHandler next)
        {
            _next = next ?? throw new ArgumentNullException(nameof(next));
        }

        public abstract void Handle(string value);
    }

    public sealed class FirtsRuleForCell : CellRequestTemplate
    {
        public FirtsRuleForCell(IHandler next) : base(value, next) { }
        public override void Handle(string value)
        {
            if(value is number)
            {
                _next.Handle(value);
            }
            else
            {
                //print "Wrong cell value";
            }
        }
    }

    public sealed class SecondRuleForCell : CellRequestTemplate
    {
        public SecondRuleForCell(IHandler next) : base(value, next) { }
        public override void Handle(string value)
        {
            //if some validation
            //do something
            //else 
            //
            _next.Handle(value);

        }
    }

    public sealed class EndOfChain : IHandler
    {
        public void Handle(string value)
        {
            throw new InvalidOperationException("End of Chaing, cant handle");
        }
    }

    public interface IHandleCellFactory
    {
        IHandler CreateHandler();
    }

    public sealed class Form1GridHandler : IHandleCellFactory
    {
        public IHandler CreateHandler()
        {
            return new FirtsRuleForCell(new SecondRuleForCell(new EndOfChain()));
        }
    }

    public sealed class Form2GridHandler : IHandleCellFactory
    {
        public IHandler CreateHandler()
        {
            return new SecondRuleForCell(new EndOfChain());
        }
    }


    public abstract class ClientCode
    {
        private void dataGrid_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
        {
            // Below I demonstrate pseudo code for brevity
            var valueToHandle = string.Empty; //cell.name.value;
            var handler = new Form1GridHandler().CreateHandler();
            handler.Handle(valueToHandle);
            //continue with Execution code
        }
    }

有关设计模式的更多信息，look at this link as reference。希望这有帮助，尊重！

Answer 2

如何创建一个静态ValidationHelper类，其中包含所有验证方法，然后在需要时调用它们。

public static class ValidationHelper
{
  public static void ValidateIsNumeric(string value)
  {
    if(value is not Number){
      print "Wrong cell value";
    }
  }
}

然后你可以打电话：

private void dataGrid_CellEditEnding(object sender,DataGridCellEditEndingEventArgs e)
{
   ValidationHelper.ValidateIsNumeric(cell.name.value);
}

验证中的DRY原理？

2 个答案: