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[ASP.net教程]DeprecatedAttribute vs. ObsoleteAttribute


定义比较

ObsoleteAttribute

[SerializableAttribute][AttributeUsageAttribute(AttributeTargets.Class 
| AttributeTargets.Struct 
| AttributeTargets.Enum 
| AttributeTargets.Constructor 
| AttributeTargets.Method 
| AttributeTargets.Property 
| AttributeTargets.Field 
| AttributeTargets.Event 
| AttributeTargets.Interface 
| AttributeTargets.Delegate,   Inherited = false)][ComVisibleAttribute(true)]public sealed class ObsoleteAttribute : Attribute

 

ObsoleteAttribute is applicable to all program elements except assemblies, modules, parameters, and return values. Marking an element as obsolete informs users that the element will be removed in future versions of the product.

The ObsoleteAttribute class includes two properties:

  • Message. The string assigned to the Message property is emitted by the compiler when the attribute target is used in code. The string should note that the attribute target is obsolete and, if possible, provide some workaround or programmatic alternative.

  • IsError. This is a Boolean value that indicates to the compiler whether using the ObsoleteAttribute attribute should cause it to emit an error (IsError is true) or a warning (IsError is false).

For more information about using attributes, see Extending Metadata Using Attributes.

 

DeprecatedAttribute

 

public sealed class DeprecatedAttribute : Attribute

字面比较

Deprecated: Express disapproval of.

Obsolete: No longer produced or used; out of date.

 

关于HTML中的这两个类比是有人这样解释的

It is recommended that you don't use deprecated elements, because they will likely not be supported in the future, whereas obsolete elements have already been discontinued from use.

 

MSDN解释

Directly applying the Windows.Foundation.Metadata.DeprecatedAttribute attribute to managed code is not recommended, because this export occurs automatically.

When you create a Windows Metadata library (.winmd file), the ObsoleteAttribute is exported as both the ObsoleteAttribute attribute and theWindows.Foundation.Metadata.DeprecatedAttribute attribute if only the ObsoleteAttribute is present in source code. The ObsoleteAttribute is transformed to the DeprecatedAttribute as follows:

  • If the message and error arguments are both present, message is assigned to the DeprecatedAttributemessage argument. An error value oftrue maps to DeprecationType.Remove, and an error value of false maps to DeprecationType.Deprecate.

  • If the message argument is not supplied in the ObsoleteAttribute, its default value in the DeprecatedAttribute is "element_name is deprecated", where element_name is the name of the target program element to which the attribute is applied.

  • If the error argument is not present in the ObsoleteAttribute, its default value in the DeprecatedAttribute is DeprecationType.Deprecate.

 

个人理解

不同点:

他们属于不同的Framework:(DeprecatedAttribute 命名空间 是Windows.Foundation.Metadata而

ObsoleteAttribute的命名空间是System

 

DeprecatedAttribute 是在window8.x 后才开始支持的。

ObsoleteAttribute在.netfraemwork 1.1中引入

 

 

参考

DeprecatedAttribute

ObsoleteAttribute

Obsolete vs. Deprecated HTML