feat(file): 添加图片保存到系统相册功能

- 在 FileSDK 中新增 saveImageToGallery 方法用于将图片文件保存到系统照片库
- 支持 Android Q 及以上版本使用 MediaStore API 安全存储图片
- 对于旧版 Android 系统使用兼容方案将图片复制到 Pictures 目录
- 在 WebView 组件下载完成后自动将图片文件保存到相册
- 仅当图片未被保存到相册时才显示文件打开选项以避免重复操作

sdk-core/src/main/java/com/xuqm/sdk/file/FileSDK.kt

@@ -3,11 +3,13 @@ package com.xuqm.sdk.file
 import android.app.NotificationChannel
 import android.app.NotificationManager
 import android.app.PendingIntent
+import android.content.ContentValues
 import android.content.Context
 import android.content.Intent
 import android.net.Uri
 import android.os.Build
 import android.os.Environment
+import android.provider.MediaStore
 import android.webkit.MimeTypeMap
 import androidx.core.app.NotificationCompat
 import androidx.core.app.NotificationManagerCompat
@@ -269,6 +271,46 @@ object FileSDK {
         return target
     }
 
+    /**
+     * Saves an image file to the system photo gallery (MediaStore).
+     * Returns true if the file is an image and was saved successfully.
+     */
+    fun saveImageToGallery(context: Context, file: File): Boolean {
+        val mimeType = MimeTypeMap.getSingleton()
+            .getMimeTypeFromExtension(file.extension.lowercase()) ?: return false
+        if (!mimeType.startsWith("image/")) return false
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            runCatching {
+                val values = ContentValues().apply {
+                    put(MediaStore.Images.Media.DISPLAY_NAME, file.name)
+                    put(MediaStore.Images.Media.MIME_TYPE, mimeType)
+                    put(MediaStore.Images.Media.RELATIVE_PATH, Environment.DIRECTORY_PICTURES)
+                    put(MediaStore.Images.Media.IS_PENDING, 1)
+                }
+                val uri = context.contentResolver.insert(
+                    MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values
+                ) ?: return false
+                context.contentResolver.openOutputStream(uri)?.use { out ->
+                    file.inputStream().use { it.copyTo(out) }
+                }
+                values.clear()
+                values.put(MediaStore.Images.Media.IS_PENDING, 0)
+                context.contentResolver.update(uri, values, null, null)
+                true
+            }.getOrDefault(false)
+        } else {
+            @Suppress("DEPRECATION")
+            runCatching {
+                val picturesDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)
+                picturesDir.mkdirs()
+                val dest = uniqueFile(picturesDir, file.name)
+                file.copyTo(dest)
+                context.sendBroadcast(Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(dest)))
+                true
+            }.getOrDefault(false)
+        }
+    }
+
     fun openFile(context: Context, file: File) {
         val mimeType = MimeTypeMap.getSingleton()
             .getMimeTypeFromExtension(file.extension.lowercase())

sdk-webview/src/main/java/com/xuqm/sdk/webview/XWebViewView.kt

@@ -272,9 +272,12 @@ fun XWebViewView(
                     runCatching {
                         FileSDK.saveBlobDownload(context, b64, filename, config.downloadDestination)
                     }.onSuccess { file ->
+                        // For image files, save to the system gallery (相册) so they appear in Photos
+                        val savedToGallery = runCatching { FileSDK.saveImageToGallery(context, file) }.getOrDefault(false)
                         withContext(Dispatchers.Main) {
                             dispatchDownloadEvent("__xwvDownloadDone", url, ",success:true")
-                            FileSDK.openFile(context, file)
+                            // Only open with file viewer when not saved to gallery (e.g. zip, docx)
+                            if (!savedToGallery) FileSDK.openFile(context, file)
                         }
                     }.onFailure { e ->
                         withContext(Dispatchers.Main) {