C# ReSharper-使用Microsoft.Contracts时可能为空的赋值
是否有任何方法可以向ReSharper指示空引用不会发生,因为契约式设计需要检查?例如,以下代码将在第7行和第8行的ReSharper中发出警告(C# ReSharper-使用Microsoft.Contracts时可能为空的赋值,c#,resharper,code-contracts,design-by-contract,microsoft-contracts,C#,Resharper,Code Contracts,Design By Contract,Microsoft Contracts,是否有任何方法可以向ReSharper指示空引用不会发生,因为契约式设计需要检查?例如,以下代码将在第7行和第8行的ReSharper中发出警告(可能为标有“NotNull”属性的实体分配“null”): private Dictionary<string, string> _Lookup = new Dictionary<string, string>(); public void Foo(string s) { Contract.Requires(!Stri
可能为标有“NotNull”属性的实体分配“null”):
private Dictionary<string, string> _Lookup = new Dictionary<string, string>();
public void Foo(string s)
{
Contract.Requires(!String.IsNullOrEmpty(s));
if (_Lookup.ContainsKey(s))
_Lookup.Remove(s);
}
- 重新启动Visual Studio,消息就会消失李>
我想你可以,但这不是小事。看看
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
例如,对于NUnit断言,它们使用AssertionMethodAttribute进行注释。这告诉Resharpers代码检查,如果您通过了Assert.IsNotNull(foo);然后foo不能为null,它将不再产生“可能的'null'赋值…”警告
您可以生成一个对合同进行注释的xml文件。需要方法来指示它与断言类似。注意:从当前的R#8.0 EAP开始,包含此功能
以下是当前(即NET 4.0)版本代码契约的解决方案:
在…\ExternalAnnotations\mscorlib\Contracts.xml
中添加以下内容:
<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>
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0
0
0
0
0
0
0
0
0
删除断言时,消息消失的原因是R#在默认情况下以“乐观”模式工作。它假定所有内容都是非null的,直到您执行了一些指示它实际上可以为null的操作。这就是将调用添加到String.IsNullOrEmpty
时发生的情况。您正在声明s
实际上可以为null。它只是没有意识到如果出现这种情况,Contract.Requires
方法将停止执行,但是您已经用注释解决了这个问题
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。我想补充一点,对于编写自己的断言方法的人,您可以在不使用外部XML文件的情况下包含这些属性。在Visual Studio中,转到ReSharper>Options>code注释
,然后单击将默认实现复制到剪贴板
按钮。然后创建一个新文件(在解决方案中的任何位置),并从剪贴板粘贴代码。现在,您可以创建如下方法:
public class Require
{
[AssertionMethod]
public static void That(
[AssertionCondition(AssertionConditionType.IS_TRUE)]
bool requiredCondition,
string message = null)
{
...
}
...
}
现在,对Require.That(a!=null)
的任何调用都将向ReSharper指示,如果a
为null,您将无法通过此行。与ExternalAnnotations技术不同,这将适用于使用您的方法的任何人,而无需他们做任何额外的工作
更新
从版本7开始,Resharper已经更改了他们的合同注释模型。下面是上述方法现在的样子:
public class Require
{
[ContractAnnotation("requiredCondition:false => halt")]
public static void That(
bool requiredCondition,
string message = null)
{
...
}
...
}
我使用了Porges的XML,并为Assert和Aspect方法添加了注释。如果其他人想添加更多的方法,我将把这个答案放到wiki上
<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>
0
0
0
0
0
0
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0
0
TL;DR-向项目中添加条件编译符号CONTRACTS\u FULL
。
Contract.Requires(…)
方法为空且已禁用,除非启用并使用代码联系人重写器。通过手动运行重写器,或者(通常)通过Visual Studio项目属性启用重写器,您将在编译和重写的二进制文件中保留契约。需要(…)
代码。您知道该代码可以工作,并且忽略Resharper警告,您可以运行它并进行测试
那有什么问题?Resharper不知道代码契约正在运行,因为它们实际上只在(后期)编译时注入。在Resharper看来,它的禁用方式与DEBUG
预处理器符号的工作方式以及Visual Studio如何使代码中不属于已编译二进制文件的区域变灰相同
#ifdef调试
WriteLine(“我处于调试模式,所以这可能是一个调试构建。”);
#否则
WriteLine(“让我们假设这是一个发布版本。”);
#恩迪夫
根据(第2章,第一段)和ContractExtensions.cs
(包含在code Contracts安装文件夹中)中的源代码,Contracts\u FULL
需要在编译之前进行设置。使用和忽略(编译时不包括),除非设置了标志。Resharper尊重此标志,并假定
<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>
<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=>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=>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=>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=>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=>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=>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=>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=>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=>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=>halt</argument>
</attribute>
</member>
</assembly>