.NET MAUI iOS端Transfer-Encoding: identity问题调整方案咨询

以下是无需修改服务器代码的前提下，针对.NET MAUI iOS端的调整方案，按优先级尝试：

1. 强制HttpClient启用Chunked编码发送请求 #

MAUI iOS的HttpClient默认可能未主动设置Transfer-Encoding: chunked请求头，导致服务器返回非chunked响应。可在创建HttpClient时全局配置，或针对单个请求设置：

// 全局配置HttpClient
var httpClient = new HttpClient();
httpClient.DefaultRequestHeaders.TransferEncodingChunked = true;

// 或针对单个请求单独设置
var graphqlRequest = new HttpRequestMessage(HttpMethod.Post, "你的GraphQL服务地址");
graphqlRequest.Headers.TransferEncodingChunked = true;
graphqlRequest.Content = new StringContent(
    "{你的GraphQL请求体}", 
    Encoding.UTF8, 
    "application/json"
);

var response = await httpClient.SendAsync(graphqlRequest);

2. 自定义NSUrlSessionHandler配置（iOS底层调整） #

MAUI iOS默认使用NSUrlSessionHandler作为HTTP请求的底层处理器，可通过修改其会话配置，强制携带chunked编码头：

// 创建自定义NSUrlSession配置
var sessionConfig = NSUrlSessionConfiguration.DefaultSessionConfiguration;
sessionConfig.HttpAdditionalHeaders = new NSDictionary(
    "Transfer-Encoding", "chunked"
);

// 初始化带自定义配置的Handler
var nsHandler = new NSUrlSessionHandler
{
    SessionConfiguration = sessionConfig
};

// 使用该Handler创建HttpClient
var httpClient = new HttpClient(nsHandler);

3. 拦截并修改响应头（适配服务器返回的identity编码） #

如果服务器仍返回Transfer-Encoding: identity，可通过自定义DelegatingHandler拦截响应，修改头信息以适配客户端的解析逻辑：

public class ChunkedResponseInterceptor : DelegatingHandler
{
    public ChunkedResponseInterceptor(HttpMessageHandler innerHandler) 
        : base(innerHandler) { }

    protected override async Task<HttpResponseMessage> SendAsync(
        HttpRequestMessage request, 
        CancellationToken cancellationToken)
    {
        var response = await base.SendAsync(request, cancellationToken);
        
        // 替换响应头的Transfer-Encoding为chunked
        response.Headers.TransferEncoding.Clear();
        response.Headers.TransferEncodingChunked = true;
        
        return response;
    }
}

// 使用方式
var baseHandler = new NSUrlSessionHandler();
var interceptHandler = new ChunkedResponseInterceptor(baseHandler);
var httpClient = new HttpClient(interceptHandler);

4. 检查iOS项目Info.plist配置 #

确保项目的网络权限配置正确，比如服务器使用HTTP协议时，需在Info.plist中添加App Transport Security例外，避免请求被系统拦截或修改：

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <true/>
</dict>

注意：NSAllowsArbitraryLoads仅用于测试环境，生产环境建议配置具体的NSExceptionDomains。

内容的提问来源于stack exchange，提问作者tetri