Class NullableHelper

Namespace

Ecng.Common

Assembly

Ecng.Common.dll

Provides helper extension methods for working with nullable types.

public static class NullableHelper

Inheritance

object

NullableHelper

Inherited Members

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Methods

Convert<T, TResult>(T, Func<T, TResult>, Func<TResult>)

Converts the value to a result type using the appropriate conversion function based on whether the value is null.

public static TResult Convert<T, TResult>(this T value, Func<T, TResult> notNullFunc, Func<TResult> nullFunc) where T : class

Parameters

value T

The input value to convert.

notNullFunc Func<T, TResult>

A function to convert the value when it is not null.

nullFunc Func<TResult>

A function to produce a result when the value is null.

Returns

TResult

The result of applying either notNullFunc or nullFunc to the value.

Type Parameters

T

The type of the input value. Must be a reference type.

TResult

The type of the result.

Exceptions

ArgumentNullException

Thrown when notNullFunc or nullFunc is null.

DefaultAsNull<T>(T)

Returns the default value as null if the value is equal to its default; otherwise, returns the value as a nullable type.

public static T? DefaultAsNull<T>(this T value) where T : struct

Parameters

value T

The value to check.

Returns

T?

Null if the value is the default of its type; otherwise, the value wrapped as a nullable type.

Type Parameters

T

The value type.

GetUnderlyingType(Type)

Gets the underlying type argument of the specified nullable type.

public static Type GetUnderlyingType(this Type nullableType)

Parameters

nullableType Type

The nullable type to get the underlying type from.

Returns

Type

The underlying type if the provided type is nullable; otherwise, null.

IsNull<T>(T)

Determines whether the specified value is null. For value types, this method returns false.

public static bool IsNull<T>(this T value)

Parameters

value T

The value to check for null.

Returns

bool

True if the value is null; otherwise, false.

Type Parameters

T

The type of the value.

IsNull<T>(T, bool)

Determines whether the specified value is null or its default for value types.

public static bool IsNull<T>(this T value, bool checkValueTypeOnDefault)

Parameters

value T

The value to check.

checkValueTypeOnDefault bool

If true and the type is a value type, the value is compared to its default value.

Returns

bool

True if the reference type value is null or if the value type is equal to its default value when checkValueTypeOnDefault is true; otherwise, false.

Type Parameters

T

The type of the value.

IsNullable(Type)

Determines whether the specified type is a nullable type.

public static bool IsNullable(this Type type)

Parameters

type Type

The type to inspect.

Returns

bool

True if the type is nullable; otherwise, false.

Exceptions

ArgumentNullException

Thrown when type is null.

MakeNullable(Type)

Creates a nullable type from the given type.

public static Type MakeNullable(this Type type)

Parameters

type Type

The type to make nullable.

Returns

Type

A nullable type of the given type.

TryMakeNullable(Type)

Converts the given type to a nullable type if it is a non-nullable value type.

public static Type TryMakeNullable(this Type type)

Parameters

type Type

The type to convert.

Returns

Type

The nullable version of the type if it is a value type and not already nullable; otherwise, the original type.