ConfigurationSection - StringValidator失败

Question

我希望在自定义元素中的ASP.NET web.config文件中存储三个值，因此这是我的web.config：

<?xml version="1.0"?>
<configuration>
    <configSections>
        <section name="mySection" type="Foobar.MySection,Foobar" />
    </configSections>

    <mySection baseUri="https://blargh" sid="123" key="abc" />

    <!-- etc, including <system.web> configuration -->
</configuration>

这是我的配置代码：

namespace Foobar {

public class MySection : ConfigurationSection {

    public MySection () {
    }

    [ConfigurationProperty("baseUri", IsRequired=true)]
    [StringValidator(MinLength=1)]
    public String BaseUri {
        get { return (String)this["baseUri"]; }
        set { this["baseUri"] = value; }
    }

    [ConfigurationProperty("sid", IsRequired=true)]
    [StringValidator(MinLength=1)]
    public String Sid {
        get { return (String)this["sid"]; }
        set { this["sid"] = value; }
    }

    [ConfigurationProperty("key", IsRequired=true)]
    [StringValidator(MinLength=1)]
    public String Key {
        get { return (String)this["key"]; }
        set { this["key"] = value; }
    }
}
}

我使用下面的代码加载它：

MySection section = ConfigurationManager.GetSection("mySection") as MySection;
String x = section.BaseUri;

然而，当我在ASP.NET中运行我的代码时，我得到了这个异常：

[ArgumentException: The string must be at least 1 characters long.]
System.Configuration.StringValidator.Validate(Object value) +679298
System.Configuration.ConfigurationProperty.Validate(Object value) +41

[ConfigurationErrorsException: The value for the property 'baseUri' is not valid. The error is: The string must be at least 1 characters long.]
System.Configuration.BaseConfigurationRecord.CallCreateSection(Boolean inputIsTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentConfig, ConfigXmlReader reader, String filename, Int32 line) +278
System.Configuration.BaseConfigurationRecord.CreateSectionDefault(String configKey, Boolean getRuntimeObject, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object& result, Object& resultRuntimeObject) +59
System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +1431
System.Configuration.BaseConfigurationRecord.GetSection(String configKey, Boolean getLkg, Boolean checkPermission) +56
System.Configuration.BaseConfigurationRecord.GetSection(String configKey) +8
System.Web.HttpContext.GetSection(String sectionName) +47
System.Web.Configuration.HttpConfigurationSystem.GetSection(String sectionName) +39
System.Web.Configuration.HttpConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String configKey) +6
System.Configuration.ConfigurationManager.GetSection(String sectionName) +78
<my code that calls GetSection>

为什么在我的web.config中设置了格式正确的值时，StringValidator会失败？我忽略了什么？

Answer 1

因为StringValidator是导致异常的原因，所以我做了一些谷歌搜索，显然这是.NET框架中的一个错误:拥有一个带有最小长度参数的StringValidator意味着它将始终拒绝该属性的空字符串""默认值，该值将由框架设置。

有一些变通方法，但是我不能证明在它们上面花费时间是合理的，所以我去掉了StringValidator属性，我的代码现在运行得很好。

下面是我找到的QA：Why does StringValidator always fail for custom configuration section?

Answer 2

它清楚地说明了

属性'baseUri‘的值无效

我觉得应该是

<mySection baseUri="https://blargh"  sid="123" key="abc" />

Answer 3

StringValidator是根本问题，可以通过以下任何一种方法来解决：

• Removing MinLength argument
• MinLength =0
• removing StringValidator Attribute
• adding DefaultValue to ConfigurationProperty Attribute

该属性的理想定义如下：

    [ConfigurationProperty("title", IsRequired = true, DefaultValue = "something")]
    [StringValidator(InvalidCharacters = "~!@#$%^&*()[]{}/;’\"|\\"
      , MinLength = 1
      , MaxLength = 256)]
    public string Title
    {
        get { return this["title"] as string; }
        set { this["title"] = value; }
    }