国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

Home Backend Development C++ How to Implement Conditional Validation in ASP.NET MVC?

How to Implement Conditional Validation in ASP.NET MVC?

Jan 08, 2025 pm 05:31 PM

How to Implement Conditional Validation in ASP.NET MVC?

Implementing conditional validation in ASP.NET MVC

Data annotations in ASP.NET MVC provide a convenient way to perform validation on model properties. However, sometimes you may need to implement conditional validation rules where the validity of a field depends on the value of another field.

Example: Conditionally required fields

Consider the following scenario: We have a "Person" model that contains an "IsSenior" property and a "Senior" property that contains a description. We want the "Senior.Description" property to be a required field only if "IsSenior" is set to true.

Data annotation method

This is not possible using only data annotations. The following code demonstrates this limitation:

public class Person
{
    [Required(ErrorMessage = "*")]
    public string Name { get; set; }

    public bool IsSenior { get; set; }

    public Senior Senior { get; set; }
}

public class Senior
{
    [Required(ErrorMessage = "*")]
    public string Description { get; set; }
}

IValidatableObject method

ASP.NET MVC 3 introduces a better solution for conditional validation using the IValidatableObject interface. Your model must implement this interface and provide a Validate method that accepts a ValidationContext parameter. This method can perform custom validation logic and return a collection of ValidationResult objects if any errors are found.

public class Person : IValidatableObject
{
    public string Name { get; set; }
    public bool IsSenior { get; set; }
    public Senior Senior { get; set; }

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
        if (IsSenior && String.IsNullOrEmpty(Senior?.Description))
            yield return new ValidationResult("必須提供描述。");
    }
}

By implementing the IValidatableObject interface, we can now perform conditional validation based on the value of "IsSenior". When "IsSenior" is true, the "Senior.Description" property becomes a required field.

Improved syntax (C# 6.0 and above)

In C# 6.0 and later, the Validate method can be simplified using an expression body member:

public IEnumerable<ValidationResult> Validate(ValidationContext validationContext) =>
    IsSenior && String.IsNullOrEmpty(Senior?.Description)
        ? new[] { new ValidationResult("必須提供描述。") }
        : Enumerable.Empty<ValidationResult>();

Through the above methods, we can effectively implement conditional verification in ASP.NET MVC. Note the use of the null conditional operator (?.) to safely access Senior.Description and avoid null reference exceptions.

The above is the detailed content of How to Implement Conditional Validation in ASP.NET MVC?. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undress AI Tool

Undress AI Tool

Undress images for free

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

C   Polymorphism : is function overloading a kind of polymorphism? C Polymorphism : is function overloading a kind of polymorphism? Jun 20, 2025 am 12:05 AM

Yes, function overloading is a polymorphic form in C, specifically compile-time polymorphism. 1. Function overload allows multiple functions with the same name but different parameter lists. 2. The compiler decides which function to call at compile time based on the provided parameters. 3. Unlike runtime polymorphism, function overloading has no extra overhead at runtime, and is simple to implement but less flexible.

What Are the Different Kinds of Polymorphism in C  ? Explained What Are the Different Kinds of Polymorphism in C ? Explained Jun 20, 2025 am 12:08 AM

C has two main polymorphic types: compile-time polymorphism and run-time polymorphism. 1. Compilation-time polymorphism is implemented through function overloading and templates, providing high efficiency but may lead to code bloating. 2. Runtime polymorphism is implemented through virtual functions and inheritance, providing flexibility but performance overhead.

C  : Is Polymorphism really useful? C : Is Polymorphism really useful? Jun 20, 2025 am 12:01 AM

Yes, polymorphisms in C are very useful. 1) It provides flexibility to allow easy addition of new types; 2) promotes code reuse and reduces duplication; 3) simplifies maintenance, making the code easier to expand and adapt to changes. Despite performance and memory management challenges, its advantages are particularly significant in complex systems.

C   Destructors: Common Errors C Destructors: Common Errors Jun 20, 2025 am 12:12 AM

C destructorscanleadtoseveralcommonerrors.Toavoidthem:1)Preventdoubledeletionbysettingpointerstonullptrorusingsmartpointers.2)Handleexceptionsindestructorsbycatchingandloggingthem.3)Usevirtualdestructorsinbaseclassesforproperpolymorphicdestruction.4

Polymorphism in C  : A Comprehensive Guide with Examples Polymorphism in C : A Comprehensive Guide with Examples Jun 21, 2025 am 12:11 AM

Polymorphisms in C are divided into runtime polymorphisms and compile-time polymorphisms. 1. Runtime polymorphism is implemented through virtual functions, allowing the correct method to be called dynamically at runtime. 2. Compilation-time polymorphism is implemented through function overloading and templates, providing higher performance and flexibility.

C   tutorial for people who know Python C tutorial for people who know Python Jul 01, 2025 am 01:11 AM

People who study Python transfer to C The most direct confusion is: Why can't you write like Python? Because C, although the syntax is more complex, provides underlying control capabilities and performance advantages. 1. In terms of syntax structure, C uses curly braces {} instead of indentation to organize code blocks, and variable types must be explicitly declared; 2. In terms of type system and memory management, C does not have an automatic garbage collection mechanism, and needs to manually manage memory and pay attention to releasing resources. RAII technology can assist resource management; 3. In functions and class definitions, C needs to explicitly access modifiers, constructors and destructors, and supports advanced functions such as operator overloading; 4. In terms of standard libraries, STL provides powerful containers and algorithms, but needs to adapt to generic programming ideas; 5

What Are the Various Forms of Polymorphism in C  ? What Are the Various Forms of Polymorphism in C ? Jun 20, 2025 am 12:21 AM

C polymorphismincludescompile-time,runtime,andtemplatepolymorphism.1)Compile-timepolymorphismusesfunctionandoperatoroverloadingforefficiency.2)Runtimepolymorphismemploysvirtualfunctionsforflexibility.3)Templatepolymorphismenablesgenericprogrammingfo

C   Polymorphism: Coding Style C Polymorphism: Coding Style Jun 19, 2025 am 12:25 AM

C polymorphismisuniqueduetoitscombinationofcompile-timeandruntimepolymorphism,allowingforbothefficiencyandflexibility.Toharnessitspowerstylishly:1)Usesmartpointerslikestd::unique_ptrformemorymanagement,2)Ensurebaseclasseshavevirtualdestructors,3)Emp

See all articles