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 |
是 |
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];
}
};
}