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WebView2RequestHeaders.md

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WebView2RequestHeaders.md

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205 lines (138 loc) · 5.03 KB
title RequestHeaders
parent WebView2 Package
nav_order 12

WebView2RequestHeaders Class

The WebView2RequestHeaders class is used to manage HTTP request header information.

Class Information

Property Value
Class Name WebView2RequestHeaders
COM Creatable No

Methods

GetHeader

Public Function GetHeader(ByVal name As String) As String

Gets the value of the request header with the specified name.

Parameters:

  • name - Request header name

Return Value: The value string of the request header

Example:

Private Sub WebView21_NavigationStarting(ByVal Uri As String, _
    ByVal IsUserInitiated As Boolean, ByVal IsRedirected As Boolean, _
    ByVal RequestHeaders As WebView2RequestHeaders, ByRef Cancel As Boolean)

    Dim userAgent As String
    userAgent = RequestHeaders.GetHeader("User-Agent")
    Debug.Print "User-Agent: " & userAgent
End Sub

Contains

Public Function Contains(ByVal name As String) As Boolean

Checks if a request header with the specified name exists.

Parameters:

  • name - Request header name

Return Value: Returns True if it contains, otherwise returns False

Example:

If RequestHeaders.Contains("Authorization") Then
    Debug.Print "Request contains Authorization header"
End If

AppendHeader

Public Sub AppendHeader(ByVal name As String, ByVal value As String)

Sets the value of the request header (replaces if it already exists).

Parameters:

  • name - Request header name
  • value - Request header value

Example:

' Add custom User-Agent
RequestHeaders.AppendHeader "User-Agent", "MyApp/1.0"

' Add Authorization header
RequestHeaders.AppendHeader "Authorization", "Bearer token123"

RemoveHeader

Public Sub RemoveHeader(ByVal name As String)

Removes the request header with the specified name.

Parameters:

  • name - Request header name

Example:

RequestHeaders.RemoveHeader("Cookie")

GetHeaders

Public Function GetHeaders(ByVal name As String) As WebView2HeadersCollection

Gets all values of the request header with the specified name (there may be multiple headers with the same name).

Parameters:

  • name - Request header name

Return Value: WebView2HeadersCollection collection object

Enumerator

Public Function _NewEnum() As WebView2HeadersCollection

Supports For Each to enumerate all request headers.

Example:

Private Sub WebView21_NavigationStarting(ByVal Uri As String, _
    ByVal IsUserInitiated As Boolean, ByVal IsRedirected As Boolean, _
    ByVal RequestHeaders As WebView2RequestHeaders, ByRef Cancel As Boolean)

    Dim header As WebView2Header
    For Each header In RequestHeaders
        Debug.Print header.Name & ": " & header.Value
    Next
End Sub

Usage Scenarios

1. View Request Headers in Navigation Event

Private Sub WebView21_NavigationStarting(ByVal Uri As String, _
    ByVal IsUserInitiated As Boolean, ByVal IsRedirected As Boolean, _
    ByVal RequestHeaders As WebView2RequestHeaders, ByRef Cancel As Boolean)

    Debug.Print "Navigating to: " & Uri
    Debug.Print "Request headers:"

    Dim header As WebView2Header
    For Each header In RequestHeaders
        Debug.Print "  " & header.Name & ": " & header.Value
    Next
End Sub

2. Modify Request Headers

Private Sub WebView21_NavigationStarting(ByVal Uri As String, _
    ByVal IsUserInitiated As Boolean, ByVal IsRedirected As Boolean, _
    ByVal RequestHeaders As WebView2RequestHeaders, ByRef Cancel As Boolean)

    ' Add custom request header
    RequestHeaders.AppendHeader "X-Custom-Header", "CustomValue"

    ' Replace User-Agent
    RequestHeaders.AppendHeader "User-Agent", "MyApp/2.0"
End Sub

3. Intercept Based on Request Headers

Private Sub WebView21_NavigationStarting(ByVal Uri As String, _
    ByVal IsUserInitiated As Boolean, ByVal IsRedirected As Boolean, _
    ByVal RequestHeaders As WebView2RequestHeaders, ByRef Cancel As Boolean)

    ' Intercept requests missing specific authentication header
    If Not RequestHeaders.Contains("Authorization") Then
        Debug.Print "Missing Authorization header, cancel navigation"
        Cancel = True
    End If
End Sub

Notes

  1. Modification Timing: Request header modifications can only be done in the NavigationStarting event; modifications at other times are invalid.

  2. Case Sensitivity: Request header names are case-insensitive, for example, "Content-Type" and "content-type" are considered the same.

  3. Special Request Headers: Some request headers (such as Host, Content-Length) are automatically managed by WebView2, manual modification may be invalid.

  4. Security: When handling sensitive information (such as Authorization, Cookie), pay attention to security to avoid leaks.

  5. Encoding Issues: Request header values should comply with HTTP specifications, some special characters may need encoding.