feat(http): 添加HttpContentType特性支持内容类型配置

实现接口和方法级别的HttpContentType特性，支持通过特性配置HTTP请求的内容类型
添加内容类型优先级处理逻辑（方法级 > 接口级 > Body参数级 > 默认值）
新增测试用例验证不同场景下的内容类型优先级

Author: mudtools

Core/Mud.CodeGenerator/Consts/HttpClientGeneratorConstants.cs

@@ -43,6 +43,7 @@ internal static class HttpClientGeneratorConstants
     public const string HeaderAttribute = "HeaderAttribute";
     public const string BodyAttribute = "BodyAttribute";
     public const string FilePathAttribute = "FilePathAttribute";
+    public static readonly string[] HttpContentTypeAttributeNames = ["HttpContentTypeAttribute", "HttpContentType"];
 
 
     public const string TimeoutProperty = "Timeout";

Core/Mud.ServiceCodeGenerator/HttpInvoke/Generators/RequestBuilder.cs

@@ -175,7 +175,20 @@ public void GenerateBodyParameter(StringBuilder codeBuilder, MethodAnalysisResul
 
         // 检查参数是否明确指定了ContentType
         var hasExplicitContentType = bodyAttr.NamedArguments.ContainsKey("ContentType");
-        var contentTypeExpression = hasExplicitContentType ? $"\"{contentType}\"" : "GetMediaType(_defaultContentType)";
+
+        // 获取有效的内容类型（方法级 > 接口级 > Body参数级 > 默认值）
+        string contentTypeExpression;
+        if (hasExplicitContentType)
+        {
+            contentTypeExpression = $"\"{contentType}\"";
+        }
+        else
+        {
+            var effectiveContentType = methodInfo.GetEffectiveContentType();
+            contentTypeExpression = !string.IsNullOrEmpty(effectiveContentType)
+                ? $"\"{effectiveContentType}\""
+                : "GetMediaType(_defaultContentType)";
+        }
 
         if (useStringContent)
         {

Core/Mud.ServiceCodeGenerator/HttpInvoke/Models/MethodAnalysisResult.cs

@@ -115,6 +115,25 @@ public string InterfaceName
     /// </summary>
     public List<InterfaceHeaderAttribute> InterfaceHeaderAttributes { get; set; } = [];
 
+    /// <summary>
+    /// 接口级别的内容类型（从接口的[HttpContentType]特性获取）
+    /// </summary>
+    public string? InterfaceContentType { get; set; }
+
+    /// <summary>
+    /// 方法级别的内容类型（从方法的[HttpContentType]特性获取）
+    /// </summary>
+    public string? MethodContentType { get; set; }
+
+    /// <summary>
+    /// 获取最终的内容类型（方法级优先于接口级）
+    /// </summary>
+    /// <returns>内容类型字符串，如果方法级和接口级都未定义则返回null</returns>
+    public string? GetEffectiveContentType()
+    {
+        return MethodContentType ?? InterfaceContentType;
+    }
+
     /// <summary>
     /// 无效的分析结果实例
     /// </summary>

Core/Mud.ServiceCodeGenerator/MethodHelper.cs

@@ -35,6 +35,9 @@ public static MethodAnalysisResult AnalyzeMethod(Compilation compilation, IMetho
         var httpMethod = httpMethodAttr.Name.ToString();
         var urlTemplate = GetAttributeArgumentValue(httpMethodAttr, 0)?.ToString().Trim('"') ?? "";
 
+        // 获取方法级别的HttpContentType特性
+        var methodContentType = GetHttpContentTypeFromSymbol(methodSymbol);
+
         var parameters = methodSymbol.Parameters.Select(p =>
         {
             var parameterInfo = new ParameterInfo
@@ -64,9 +67,13 @@ public static MethodAnalysisResult AnalyzeMethod(Compilation compilation, IMetho
         var interfaceSymbol = compilation.GetSemanticModel(interfaceDecl.SyntaxTree).GetDeclaredSymbol(interfaceDecl) as INamedTypeSymbol;
         var interfaceAttributes = new HashSet<string>();
         var interfaceHeaderAttributes = new List<InterfaceHeaderAttribute>();
+        string? interfaceContentType = null;
 
         if (interfaceSymbol != null)
         {
+            // 获取接口级别的HttpContentType特性
+            interfaceContentType = GetHttpContentTypeFromSymbol(interfaceSymbol);
+
             // 检查并处理所有[Header]特性
             var headerAttributes = interfaceSymbol.GetAttributes()
                 .Where(attr => (attr.AttributeClass?.Name == "HeaderAttribute" || attr.AttributeClass?.Name == "Header"));
@@ -125,7 +132,9 @@ public static MethodAnalysisResult AnalyzeMethod(Compilation compilation, IMetho
             IgnoreImplement = HasMethodAttribute(methodSymbol, HttpClientGeneratorConstants.IgnoreImplementAttributeNames),
             IgnoreWrapInterface = HasMethodAttribute(methodSymbol, HttpClientGeneratorConstants.IgnoreWrapInterfaceAttributeNames),
             InterfaceAttributes = interfaceAttributes,
-            InterfaceHeaderAttributes = interfaceHeaderAttributes
+            InterfaceHeaderAttributes = interfaceHeaderAttributes,
+            InterfaceContentType = interfaceContentType,
+            MethodContentType = methodContentType
         };
     }
     private static AttributeSyntax? FindHttpMethodAttribute(MethodDeclarationSyntax methodSyntax)
@@ -198,6 +207,36 @@ private static string GetHeaderName(AttributeData headerAttr)
     }
 
 
+    /// <summary>
+    /// 从符号获取HttpContentType特性的ContentType值
+    /// </summary>
+    /// <param name="symbol">符号（方法或接口）</param>
+    /// <returns>Content-Type值，如果未定义则返回null</returns>
+    private static string? GetHttpContentTypeFromSymbol(ISymbol symbol)
+    {
+        if (symbol == null)
+            return null;
+
+        // 查找HttpContentType特性
+        var httpContentTypeAttr = AttributeDataHelper.GetAttributeDataFromSymbol(
+            symbol,
+            HttpClientGeneratorConstants.HttpContentTypeAttributeNames);
+
+        if (httpContentTypeAttr == null)
+            return null;
+
+        // 优先从构造函数参数获取
+        if (httpContentTypeAttr.ConstructorArguments.Length > 0)
+        {
+            var constructorArg = httpContentTypeAttr.ConstructorArguments[0].Value?.ToString();
+            if (!string.IsNullOrEmpty(constructorArg))
+                return constructorArg;
+        }
+
+        // 从命名参数获取
+        return AttributeDataHelper.GetStringValueFromAttribute(httpContentTypeAttr, ["ContentType"]);
+    }
+
     /// <summary>
     /// 查询方法的语法对象。
     /// </summary>

Test/CodeGeneratorTest/WebApi/IContentTypeTestApi.cs

@@ -0,0 +1,96 @@
+namespace CodeGeneratorTest.WebApi;
+
+
+/// <summary>
+/// 用于测试 HttpContentType 特性的优先级功能
+/// 测试场景：
+/// 1. 接口级特性 vs 方法级特性（方法级优先）
+/// 2. 构造函数参数 vs 命名参数
+/// 3. 默认值回退
+/// </summary>
+[HttpClientApi("https://api.example.com")]
+[HttpContentType("application/xml")]
+public interface IContentTypeTestApi
+{
+    /// <summary>
+    /// 方法1：接口使用 application/xml，方法覆盖为 application/json
+    /// 预期结果：使用 application/json
+    /// </summary>
+    [Post("/api/test1")]
+    [HttpContentType("application/json")]
+    Task<string> TestMethod1Async([Body] string data);
+
+    /// <summary>
+    /// 方法2：接口使用 application/xml，方法覆盖为 text/plain
+    /// 预期结果：使用 text/plain
+    /// </summary>
+    [Post("/api/test2")]
+    [HttpContentType("text/plain")]
+    Task<string> TestMethod2Async([Body] string data);
+
+    /// <summary>
+    /// 方法3：接口使用 application/xml，方法未指定
+    /// 预期结果：使用 application/xml（从接口继承）
+    /// </summary>
+    [Post("/api/test3")]
+    Task<string> TestMethod3Async([Body] string data);
+
+    /// <summary>
+    /// 方法4：使用命名参数方式指定内容类型
+    /// 预期结果：使用 application/x-www-form-urlencoded
+    /// </summary>
+    [Post("/api/test4")]
+    [HttpContentType(ContentType = "application/x-www-form-urlencoded")]
+    Task<string> TestMethod4Async([Body] string data);
+
+    /// <summary>
+    /// 方法5：使用构造函数参数方式指定内容类型
+    /// 预期结果：使用 multipart/form-data
+    /// </summary>
+    [Post("/api/test5")]
+    [HttpContentType("multipart/form-data")]
+    Task<string> TestMethod5Async([Body] string data);
+}
+
+
+/// <summary>
+/// 用于测试 HttpContentType 特性的默认值回退功能
+/// 测试场景：
+/// 接口和方法均未定义 HttpContentType 特性
+/// </summary>
+[HttpClientApi("https://api.example2.com")]
+public interface IContentTypeDefaultTestApi
+{
+    /// <summary>
+    /// 方法1：接口和方法均未指定内容类型
+    /// 预期结果：使用默认值 application/json
+    /// </summary>
+    [Post("/api/default")]
+    Task<string> TestDefaultAsync([Body] string data);
+}
+
+
+/// <summary>
+/// 用于测试 HttpContentType 特性与 Body 参数 ContentType 的优先级
+/// 测试场景：
+/// Body 参数的 ContentType 优先级最高
+/// </summary>
+[HttpClientApi("https://api.example3.com")]
+[HttpContentType("application/xml")]
+public interface IContentTypeBodyPriorityTestApi
+{
+    /// <summary>
+    /// 方法1：接口使用 application/xml，方法使用 application/json，Body 参数使用 text/html
+    /// 预期结果：使用 text/html（Body 参数优先级最高）
+    /// </summary>
+    [Post("/api/priority1")]
+    [HttpContentType("application/json")]
+    Task<string> TestPriority1Async([Body(ContentType = "text/html")] string data);
+
+    /// <summary>
+    /// 方法2：接口使用 application/xml，方法未指定，Body 参数使用 application/json
+    /// 预期结果：使用 application/json（Body 参数优先级最高）
+    /// </summary>
+    [Post("/api/priority2")]
+    Task<string> TestPriority2Async([Body(ContentType = "application/json")] string data);
+}

Test/Mud.Common.CodeGenerator/Http/HttpContentTypeAttribute.cs

@@ -0,0 +1,31 @@
+namespace Mud.Common.CodeGenerator;
+
+
+/// <summary>
+/// 用于指定HTTP请求的内容类型
+/// </summary>
+[AttributeUsage(AttributeTargets.Interface | AttributeTargets.Method, AllowMultiple = false)]
+public class HttpContentTypeAttribute : Attribute
+{
+    /// <summary>
+    /// HTTP请求的内容类型
+    /// </summary>
+    public string ContentType { get; set; } = "application/json";
+
+    /// <summary>
+    /// 使用默认的"application/json"内容类型初始化一个新的实例
+    /// </summary>
+    public HttpContentTypeAttribute()
+    {
+
+    }
+
+    /// <summary>
+    /// 使用指定的内容类型初始化一个新的实例
+    /// </summary>
+    /// <param name="contentType"></param>
+    public HttpContentTypeAttribute(string contentType)
+    {
+        ContentType = contentType;
+    }
+}