System.Net.Http.Headers.RangeConditionHeaderValue

In: System.Net.Http.Headers | Namespace: System.Net.Http.Headers

🏛️

RangeConditionHeaderValue

Represents a Range condition header value.

Class RangeConditionHeaderValue

This class represents a Range condition header value, which is used in HTTP requests to specify a byte range within a resource. It typically consists of a date or an ETag value and a comparison operator.

Range condition headers are commonly used in conjunction with caching mechanisms or for partial content retrieval. For example, an If-Modified-Since header uses a date condition, while an If-Match or If-None-Match header uses an ETag condition.

The RangeConditionHeaderValue class encapsulates these conditions, providing a structured way to parse and represent them.

Constructors

RangeConditionHeaderValue(DateTimeOffset date)
Initializes a new instance of the RangeConditionHeaderValue class with a specified date.
RangeConditionHeaderValue(string etag)
Initializes a new instance of the RangeConditionHeaderValue class with a specified ETag.

Properties

DateTimeOffset? Date
Gets or sets the date for the condition.
string Etag
Gets or sets the ETag for the condition.

Methods

static RangeConditionHeaderValue Parse(string value)
Parses a string representation of a Range condition header value.
static bool TryParse(string value, out RangeConditionHeaderValue parsedValue)
Tries to parse a string representation of a Range condition header value.

Members

Constructors

RangeConditionHeaderValue(DateTimeOffset date)

Initializes a new instance of the RangeConditionHeaderValue class using the specified date.

Parameters

Name	Type	Description
`date`	`DateTimeOffset`	The date to use for the condition.

RangeConditionHeaderValue(string etag)

Initializes a new instance of the RangeConditionHeaderValue class using the specified ETag.

Parameters

Name	Type	Description
`etag`	`string`	The ETag to use for the condition.

Properties

DateTimeOffset? Date
Gets or sets the date associated with the Range condition header. This is only valid if the condition is based on a date.
string Etag
Gets or sets the ETag associated with the Range condition header. This is only valid if the condition is based on an ETag.

Methods

static RangeConditionHeaderValue Parse(string value)

Parses a string representation of a Range condition header value.

Parameters

Name	Type	Description
`value`	`string`	The string to parse.

Returns

RangeConditionHeaderValue: A RangeConditionHeaderValue instance.

Exceptions

FormatException: The string is not a valid Range condition header value.

static bool TryParse(string value, out RangeConditionHeaderValue parsedValue)

Tries to parse a string representation of a Range condition header value.

Parameters

Name	Type	Description
`value`	`string`	The string to parse.
`parsedValue`	`out RangeConditionHeaderValue`	When this method returns, contains the parsed `RangeConditionHeaderValue` instance if the parsing succeeded, or `null` if the parsing failed.

Returns

bool: true if the string was parsed successfully; otherwise, false.

Examples

Creating a RangeConditionHeaderValue with a Date


using System;
using System.Net.Http.Headers;

// Create a date-based condition for a resource modified after a specific date.
DateTimeOffset lastModified = new DateTimeOffset(2023, 10, 26, 10, 0, 0, TimeSpan.Zero);
RangeConditionHeaderValue dateCondition = new RangeConditionHeaderValue(lastModified);

Console.WriteLine($"Date Condition: {dateCondition}");
// Output might look like: Date Condition:  (format may vary)

Creating a RangeConditionHeaderValue with an ETag


using System.Net.Http.Headers;

// Create an ETag-based condition for a resource.
string etagValue = "\"abcde12345\"";
RangeConditionHeaderValue etagCondition = new RangeConditionHeaderValue(etagValue);

Console.WriteLine($"ETag Condition: {etagCondition}");
// Output: ETag Condition: "abcde12345"

Parsing a RangeConditionHeaderValue


using System;
using System.Net.Http.Headers;

string httpHeaderValue = "If-Modified-Since: Tue, 15 Nov 1994 12:45:26 GMT";
string[] parts = httpHeaderValue.Split(':');
if (parts.Length > 1)
{
    string conditionString = parts[1].Trim();
    if (RangeConditionHeaderValue.TryParse(conditionString, out RangeConditionHeaderValue parsedCondition))
    {
        Console.WriteLine($"Parsed Condition: {parsedCondition}");
        if (parsedCondition.Date.HasValue)
        {
            Console.WriteLine($"  Condition Type: Date");
            Console.WriteLine($"  Date: {parsedCondition.Date.Value}");
        }
        else if (!string.IsNullOrEmpty(parsedCondition.Etag))
        {
            Console.WriteLine($"  Condition Type: ETag");
            Console.WriteLine($"  ETag: {parsedCondition.Etag}");
        }
    }
    else
    {
        Console.WriteLine($"Failed to parse '{conditionString}' as a RangeConditionHeaderValue.");
    }
}