CA1023:索引器不应是多维的

类型名

IndexersShouldNotBeMultidimensional

CheckId

CA1023

类别

Microsoft.Design

是否重大更改

原因

公共或受保护类型包含一个公共或受保护索引器,该索引器使用多个索引。

规则说明

索引器(即索引属性)应该使用一个索引。 多维索引器会大大降低库的可用性。 如果设计需要使用多个索引,请重新考虑类型是否代表逻辑数据存储。 否则,请使用方法。

如何解决冲突

要修复与该规则的冲突,请将设计更改为使用长整型或字符串索引,或使用方法来替代索引器。

何时禁止显示警告

仅在认真考虑非标准索引器的需要后,再禁止显示此规则发出的警告。

示例

下面的示例演示类型 DayOfWeek03,该类型的多维索引器与该规则冲突。 此索引器可以视为一种转换类型,因此公开为方法更为合适。 此类型在 RedesignedDayOfWeek03 中重新设计,以满足该规则。

Imports System

Namespace DesignLibrary

    Public Class DayOfWeek03

        Private dayOfWeek(,) As String = {{"Wed", "Thu", "..."}, _
                                          {"Sat", "Sun", "..."}}
                                          ' ...

        Default ReadOnly Property Item(month As Integer, day As Integer) As String
            Get
                Return dayOfWeek(month - 1, day - 1)
            End Get
        End Property

    End Class

    Public Class RedesignedDayOfWeek03

        Private dayOfWeek() As String = _
            {"Tue", "Wed", "Thu", "Fri", "Sat", "Sun", "Mon"}
        Private daysInPreviousMonth() As Integer = _
            {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30}

        Function GetDayOfWeek(month As Integer, day As Integer) As String
            Return dayOfWeek((daysInPreviousMonth(month - 1) + day) Mod 7)
        End Function

    End Class

End Namespace
using System;

namespace DesignLibrary
{
    public class DayOfWeek03
    {
        string[,] dayOfWeek = {{"Wed", "Thu", "..."}, 
                               {"Sat", "Sun", "..."}};
                               // ...

        public string this[int month, int day]
        {
            get
            {
                return dayOfWeek[month - 1, day - 1];
            }
        }
    }

    public class RedesignedDayOfWeek03
    {
        string[] dayOfWeek = 
            {"Tue", "Wed", "Thu", "Fri", "Sat", "Sun", "Mon"};

        int[] daysInPreviousMonth = 
            {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30};

        public string GetDayOfWeek(int month, int day)
        {
            return dayOfWeek[(daysInPreviousMonth[month - 1] + day) % 7];
        }
    }
}
using namespace System;

namespace DesignLibrary
{
    public ref class DayOfWeek03
    {
        array<String^, 2>^ dayOfWeek;

    public:
        property String^ default[int,  int]
        {
            String^ get(int month, int day)
            {
                return dayOfWeek[month - 1, day - 1];
            }
        }

        DayOfWeek03()
        {
            dayOfWeek = gcnew array<String^, 2>(12, 7);
            dayOfWeek[0,0] = "Wed";
            dayOfWeek[0,1] = "Thu";
            // ...
            dayOfWeek[1,0] = "Sat";
            dayOfWeek[1,1] = "Sun";
            // ...
        }
    };

    public ref class RedesignedDayOfWeek03
    {
        static array<String^>^ dayOfWeek = 
            {"Tue", "Wed", "Thu", "Fri", "Sat", "Sun", "Mon"};

        static array<int>^ daysInPreviousMonth = 
            {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30};

    public:
        String^ GetDayOfWeek(int month, int day)
        {
            return dayOfWeek[(daysInPreviousMonth[month - 1] + day) % 7];
        }
    };
}

相关规则

CA1043:将整型或字符串参数用于索引器

CA1024:在适用处使用属性