From a67af0485e4720e6e9ca38a89b95448564eafea7 Mon Sep 17 00:00:00 2001
From: ccnetcore <cc2016cc>
Date: Sun, 11 Jan 2026 17:27:57 +0800
Subject: [PATCH] =?UTF-8?q?fix:=20=E4=BC=98=E5=8C=96=20Gemini=20=E5=9B=BE?=
 =?UTF-8?q?=E7=89=87=20base64=20=E8=8E=B7=E5=8F=96=E9=80=BB=E8=BE=91?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

从最后一个 part 逆序查找 inlineData 和 text，避免只读取首个 part 导致图片缺失
支持根据 inlineData.mimeType 动态生成 data:image 前缀
增强对多 part 返回结构的兼容性，提高图片解析成功率
---
 .../Gemini/GeminiGenerateContentAcquirer.cs   | 66 +++++++++++--------
 1 file changed, 39 insertions(+), 27 deletions(-)

diff --git a/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain.Shared/Dtos/Gemini/GeminiGenerateContentAcquirer.cs b/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain.Shared/Dtos/Gemini/GeminiGenerateContentAcquirer.cs
index 65012772..ca70532a 100644
--- a/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain.Shared/Dtos/Gemini/GeminiGenerateContentAcquirer.cs
+++ b/Yi.Abp.Net8/module/ai-hub/Yi.Framework.AiHub.Domain.Shared/Dtos/Gemini/GeminiGenerateContentAcquirer.cs
@@ -109,46 +109,58 @@ public static class GeminiGenerateContentAcquirer
 
     /// <summary>
     /// 获取图片 base64（包含 data:image 前缀）
-    /// 优先从 inlineData.data 中获取，其次从 markdown text 中解析
+    /// 从最后一个 part 开始查找 inlineData，找不到再从最后一个 part 开始查找 text
     /// </summary>
     public static string GetImagePrefixBase64(JsonElement response)
     {
-        // Step 1: 优先尝试从 candidates[0].content.parts[0].inlineData.data 获取
-        var inlineBase64 = response
-            .GetPath("candidates", 0, "content", "parts", 0, "inlineData", "data")
-            .GetString();
-
-        if (!string.IsNullOrEmpty(inlineBase64))
-        {
-            // 默认按 png 格式拼接前缀
-            return $"data:image/png;base64,{inlineBase64}";
-        }
-
-        // Step 2: fallback，从 candidates[0].content.parts[0].text 中解析 markdown 图片
-        var text = response
-            .GetPath("candidates", 0, "content", "parts", 0, "text")
-            .GetString();
-
-        if (string.IsNullOrEmpty(text))
+        var parts = response.GetPath("candidates", 0, "content", "parts");
+        if (!parts.HasValue || parts.Value.ValueKind != JsonValueKind.Array)
         {
             return string.Empty;
         }
 
-        // markdown 图片格式: ![image](data:image/png;base64,xxx)
-        var startMarker = "(data:image/";
-        var startIndex = text.IndexOf(startMarker, StringComparison.Ordinal);
-        if (startIndex < 0)
+        var partsArray = parts.Value.EnumerateArray().ToList();
+        if (partsArray.Count == 0)
         {
             return string.Empty;
         }
 
-        startIndex += 1; // 跳过 "("
-        var endIndex = text.IndexOf(')', startIndex);
-        if (endIndex <= startIndex)
+        // Step 1: 从最后一个 part 开始查找 inlineData
+        for (int i = partsArray.Count - 1; i >= 0; i--)
         {
-            return string.Empty;
+            var inlineBase64 = partsArray[i].GetPath("inlineData", "data").GetString();
+            if (!string.IsNullOrEmpty(inlineBase64))
+            {
+                var mimeType = partsArray[i].GetPath("inlineData", "mimeType").GetString() ?? "image/png";
+                return $"data:{mimeType};base64,{inlineBase64}";
+            }
         }
 
-        return text.Substring(startIndex, endIndex - startIndex);
+        // Step 2: 从最后一个 part 开始查找 text 中的 markdown 图片
+        for (int i = partsArray.Count - 1; i >= 0; i--)
+        {
+            var text = partsArray[i].GetPath("text").GetString();
+            if (string.IsNullOrEmpty(text))
+            {
+                continue;
+            }
+
+            // markdown 图片格式: ![image](data:image/png;base64,xxx)
+            var startMarker = "(data:image/";
+            var startIndex = text.IndexOf(startMarker, StringComparison.Ordinal);
+            if (startIndex < 0)
+            {
+                continue;
+            }
+
+            startIndex += 1; // 跳过 "("
+            var endIndex = text.IndexOf(')', startIndex);
+            if (endIndex > startIndex)
+            {
+                return text.Substring(startIndex, endIndex - startIndex);
+            }
+        }
+
+        return string.Empty;
     }
 }
\ No newline at end of file