blocks|key|3323042|text|我认为你可以，但这不是微不足道的。看一看Resharper+online+help+for+code+annotation|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3323043|他们注释了BCL类和NUnit框架(以及更多)，以增强Resharpers代码检查功能。|3323044|例如，使用它们用AssertionMethodAttribute注释的NUnit断言。这告诉Resharpers代码检查，如果您通过了Assert.IsNotNull(+foo+)；，那么foo不能为空，并且它不会产生“可能的‘空’赋值...”再警告一次。|3323045|您可以生成一个对Contracts.Requires方法进行注释的xml文件，以表明它就像一个断言。|3323046|entityMap|0|LINK|mutability|MUTABLE|url|http://www.jetbrains.com/resharper/webhelp/index.jsp?Code_Analysis__External_Annotations.html^0|K|15|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@$A|S|B|T|1|U]]|C|$]]|$1|D|3|E|5|6|7|V|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|W|8|@]|9|@]|C|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@]|C|$]]|$1|J|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|K|$L|$5|M|N|O|C|$P|Q]]]]

I think you can but it isn't trivial. Take a look at <a href="http://www.jetbrains.com/resharper/webhelp/index.jsp?Code_Analysis__External_Annotations.html" rel="nofollow noreferrer">Resharper online help for code annotation</a>

They annotated the BCL classes and the NUnit framework (and more) to enhance Resharpers code inspection capabilities. 

For example with the NUnit asserts they annotated with an AssertionMethodAttribute. This tells Resharpers code inspection that if you got past an Assert.IsNotNull(foo); then foo must not be null and it won't produce the "Possible 'null' assignment..." warning anymore.

You could produce an xml file annotating the Contracts.Requires method to indicate that it is just like an Assert.

blocks|key|340118|text|注意：从当前的R#+8.0EAP开始，包含此功能。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|340119|340120|以下是当前(即.NET+4.0)版本的代码契约的解决方案：|340121|在...\ExternalAnnotations\mscorlib\Contracts.xml中，添加以下内容：|CODE|340122|<assembly+name="mscorlib">
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean,+System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean,+System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
</assembly>|code-block|syntax|javascript|340123|entityMap^0|0|2|0|0|0|1|1A|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|V|8|@]|D|@]|E|$]]|$1|G|3|H|5|6|7|W|8|@]|D|@]|E|$]]|$1|I|3|J|5|6|7|X|8|@$9|Y|A|Z|B|K]]|D|@]|E|$]]|$1|L|3|M|5|N|7|10|8|@]|D|@]|E|$O|P]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

Note: as of the current R# 8.0 EAP, this functionality is included.

<hr>

Here's the solution for the current (i.e. .NET 4.0) version of Code Contracts:

Inside <code>...\ExternalAnnotations\mscorlib\Contracts.xml</code>, add the following:

<pre><code>&lt;assembly name="mscorlib"&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean, System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean, System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
&lt;/assembly&gt;
</code></pre>

blocks|key|343640|text|当您删除断言时，消息消失的原因是默认情况下R#以“乐观”模式工作。它假设所有东西都是非空的，直到你做了一些事情，表明它实际上可以是空的。这就是将调用添加到String.IsNullOrEmpty时所发生的事情。您是在声明s实际上可能为空。它只是不知道Contract.Requires方法会在这种情况下停止执行，而是知道您使用注释解决了这个问题。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|343641|在R#+5.0中，您可以更改为悲观模式，在每个角落都假设最坏的情况。|343642|entityMap^0|25|K|32|1|3H|H|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|R|8|@]|D|@]|E|$]]]|I|$]]

The reason the message goes away when you remove the assertion is that R# works in an "optimistic" mode by default. It assumes everything is non-null until you do something that indicates it can actually be null. That's what happens when you add the call to <code>String.IsNullOrEmpty</code>. You're stating that <code>s</code> could actually be null. It just isn't aware that the <code>Contract.Requires</code> method will stop execution if that's the case, but that you solved with the annotation.

In R# 5.0 you can change to a pessimistic mode that assumes the worst at every corner.

blocks|key|3110141|text|我想补充的是，对于编写自己的断言方法之类的人，您可以在没有外部XML文件的情况下包含这些属性。在Visual+Studio中，转到ReSharper+>+Options+>+Code+Annotations并单击Copy+default+implementation+to+clipboard按钮。然后创建一个新文件(解决方案中所需的任何位置)，并粘贴剪贴板中的代码。现在，您可以创建如下方法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3110142|public+class+Require
{
++++[AssertionMethod]
++++public+static+void+That(
++++++++[AssertionCondition(AssertionConditionType.IS_TRUE)]+
++++++++bool+requiredCondition,
++++++++string+message+=+null)
++++{
++++++++...
++++}
...
}|code-block|syntax|javascript|3110143|现在，任何对Require.That(a+!=+null)的调用都将向ReSharper表明，如果a为null，则无法越过此行。与ExternalAnnotations技术不同，这将适用于使用您的方法的任何人，而不需要他们做任何额外的工作。|3110144|更新|3110145|Resharper已经从版本7开始更改了他们的契约注释模型。下面是上面的方法现在的样子：|3110146|public+class+Require
{
++++[ContractAnnotation("requiredCondition:false+=>+halt")]
++++public+static+void+That(
++++++++bool+requiredCondition,
++++++++string+message+=+null)
++++{
++++++++...
++++}
...
}|3110147|entityMap^0|1T|12|2Y|14|0|0|6|N|1D|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|M|3|N|5|6|7|15|8|@]|D|@]|E|$]]|$1|O|3|P|5|6|7|16|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|17|8|@]|D|@]|E|$I|J]]|$1|S|3|-4|5|6|7|18|8|@]|D|@]|E|$]]]|T|$]]

I'd like to add that for people writing their own assertion methods and such, you can include these attributes without an external XML file. In Visual Studio, go to <code>ReSharper &gt; Options &gt; Code Annotations</code> and click the <code>Copy default implementation to clipboard</code> button. Then create a new file (anywhere you want in your solution) and paste in the code from the clipboard. Now, you can create methods like this:
<pre><code>public class Require
{
 [AssertionMethod]
 public static void That(
 [AssertionCondition(AssertionConditionType.IS_TRUE)] 
 bool requiredCondition,
 string message = null)
 {
 ...
 }
...
}
</code></pre>
Now any call to <code>Require.That(a != null)</code> will indicate to ReSharper that you can't get past this line if <code>a</code> is null. Unlike the ExternalAnnotations technique, this will work for anyone using your methods, without any additional work on their part.
<h3>Update</h3>
Resharper has changed their contract annotation model as of version 7. Here's what the above method would look like now:
<pre><code>public class Require
{
 [ContractAnnotation(&quot;requiredCondition:false =&gt; halt&quot;)]
 public static void That(
 bool requiredCondition,
 string message = null)
 {
 ...
 }
...
}
</code></pre>

blocks|key|3323243|text|我采用了Porges的XML，并为Assert和Assert方法添加了注释。我将维基这个答案，以防其他人想要添加更多的方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3323244|<assembly+name="mscorlib">
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean,+System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean,+System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<parameter+name="condition">
++++++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)">
++++++++++++++++<argument>0</argument>
++++++++++++</attribute>
++++++++</parameter>
++++</member>
</assembly>|code-block|syntax|javascript|3323245|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I took Porges' XML and added annotations for the Assert and Assume methods. I'll wiki this answer in case other people want to add more methods.

<pre><code>&lt;assembly name="mscorlib"&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean, System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean, System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
&lt;/assembly&gt;
</code></pre>

blocks|key|3323280|text|从版本7开始，Resharper已经更改了他们的合同注释模型。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3323281|您需要不同的文件。新的位置(我猜只适用于地铁应用程序)是："C:\Program+Files+(x86)\JetBrains\ReSharper\v7.1\Bin\ExternalAnnotations.NETCore\System.Diagnostics.Contracts\Contracts.xml“|3323282|我使用的是Visual+Studio2012、.Net+4.5和ReSharper7.1。|3323283|内容：|3323284|<assembly+name="System.Diagnostics.Contracts">
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean,+System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean,+System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
++++<member+name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)">
++++++++<attribute+ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/>
++++++++<attribute+ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)">
++++++++++++<argument>condition:false=&gt;halt</argument>
++++++++</attribute>
++++</member>
</assembly>|code-block|syntax|javascript|3323285|entityMap^0|7|O|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|W|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|X|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|Y|8|@]|D|@]|E|$O|P]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

Resharper has changed their contract annotation model as of version 7.

You need a different file. The new location (I guess only for Metro apps) is: 
"C:\Program Files (x86)\JetBrains\ReSharper\v7.1\Bin\ExternalAnnotations\.NETCore\System.Diagnostics.Contracts\Contracts.xml"

I am using Visual Studio 2012 and .Net 4.5 and Resharper 7.1.

Content:

<pre><code>&lt;assembly name="System.Diagnostics.Contracts"&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assert(System.Boolean, System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Assume(System.Boolean, System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires``1(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Invariant(System.Boolean,System.String)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.ContractAnnotationAttribute.#ctor(System.String)"&gt;
 &lt;argument&gt;condition:false=&amp;gt;halt&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/member&gt;
&lt;/assembly&gt;
</code></pre>

Is there any way to indicate to ReSharper that a null reference won't occur because of Design-by-Contract Requires checking? For example, the following code will raise the warning (<code>Possible 'null' assignment to entity marked with 'NotNull' attribute</code>) in ReSharper on lines 7 and 8:

<pre><code>private Dictionary&lt;string, string&gt; _Lookup = new Dictionary&lt;string, string&gt;();

public void Foo(string s)
{
 Contract.Requires(!String.IsNullOrEmpty(s));

 if (_Lookup.ContainsKey(s))
 _Lookup.Remove(s);
}
</code></pre>

What is really odd is that if you remove the <code>Contract.Requires(...)</code> line, the ReSharper message goes away. 

Update

I found the solution through ExternalAnnotations which was also mentioned by Mike below. Here's an example of how to do it for a function in Microsoft.Contracts:

<ul>
<li>Create a directory called <code>Microsoft.Contracts</code> under the <code>ExternalAnnotations</code> ReSharper directory.</li>
<li>Next, Create a file called <code>Microsoft.Contracts.xml</code> and populate like so:</li>
</ul>



<pre><code>&lt;assembly name="Microsoft.Contracts"&gt;
 &lt;member name="M:System.Diagnostics.Contracts.Contract.Requires(System.Boolean)"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionMethodAttribute.#ctor"/&gt;
 &lt;parameter name="condition"&gt;
 &lt;attribute ctor="M:JetBrains.Annotations.AssertionConditionAttribute.#ctor(JetBrains.Annotations.AssertionConditionType)"&gt;
 &lt;argument&gt;0&lt;/argument&gt;
 &lt;/attribute&gt;
 &lt;/parameter&gt;
 &lt;/member&gt;
&lt;/assembly&gt;
</code></pre>



<ul>
<li>Restart Visual Studio, and the message goes away!</li>
</ul>

ReSharper - Possible Null Assignment when using Microsoft.Contracts

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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有没有办法告诉ReSharper，由于契约式设计需要检查，所以不会出现空引用？例如，下面的代码将在ReSharper的第7行和第8行引发警告(Possible 'null' assignment to entity marked with 'NotNull' attribute)：private Dictionary<...

问ReSharper -使用Microsoft.Contracts时可能的空值分配
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