fix(android): 下载改为应用内下载+系统分享sheet

- 移除 DownloadManager，改用 HttpURLConnection 下载到应用私有目录

- 通过 FileProvider 生成 content URI，调用 ACTION_SEND 弹出系统分享面板

- 下载请求携带 WebView Cookie，保证鉴权

- 版本号 1.0.40 (versionCode 42)

android-webview-app/APP_CHANGELOG.md

@@ -1,5 +1,11 @@
 # App 更新说明
 
+# 1.0.40
+- 修复 Android App 内文件下载后系统提示「下载失败」的问题：
+  - 放弃系统 DownloadManager，改为应用内下载到私有目录
+  - 下载完成后弹出系统「分享文件」面板，让用户选择保存到下载管理、QQ浏览器、微信等目标
+  - 仍保留 WebView Cookie，下载接口可正常鉴权
+
 # 1.0.39
 - 修复 Android App 内图片/视频「从本地发送」无响应的问题：在唤起系统文件选择器前主动请求 `READ_MEDIA_IMAGES` / `READ_MEDIA_VIDEO` 权限，拒绝后支持再次请求并引导到系统设置
 - 修复 Android App 内所有下载（文件卡片、markdown 下载链接）提示「下载启动失败」的问题：

android-webview-app/app/build.gradle.kts

@@ -16,8 +16,8 @@ android {
         applicationId = "com.cyjai.agent"
         minSdk = 24
         targetSdk = 35
-        versionCode = 41
+        versionCode = 42
-        versionName = "1.0.39"
+        versionName = "1.0.40"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }

android-webview-app/app/src/main/AndroidManifest.xml

@@ -18,6 +18,16 @@
         android:theme="@style/Theme.AgentWebView"
         android:usesCleartextTraffic="false">
 
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
+
         <activity
             android:name=".MainActivity"
             android:exported="true"

android-webview-app/app/src/main/java/com/cyjai/agent/MainActivity.kt

@@ -2,14 +2,13 @@ package com.cyjai.agent
 
 import android.Manifest
 import android.annotation.SuppressLint
-import android.app.DownloadManager
+import android.content.ActivityNotFoundException
 import android.content.Intent
 import android.content.pm.PackageManager
 import android.graphics.Color
 import android.net.Uri
 import android.os.Build
 import android.os.Bundle
-import android.os.Environment
 import android.provider.DocumentsContract
 import android.provider.Settings
 import android.util.Log
@@ -32,6 +31,7 @@ import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
+import androidx.core.content.FileProvider
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.WindowCompat
@@ -39,6 +39,10 @@ import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
+import java.io.File
+import java.net.HttpURLConnection
+import java.net.URL
+import java.net.URLConnection
 import java.util.Locale
 
 class MainActivity : AppCompatActivity() {
@@ -47,15 +51,12 @@ class MainActivity : AppCompatActivity() {
     private var filePathCallback: ValueCallback<Array<Uri>>? = null
     private var voiceBridge: VoiceBridge? = null
     private var pendingFileChooserParams: WebChromeClient.FileChooserParams? = null
-    private var pendingDownloadUrl: String? = null
-    private var pendingDownloadFileName: String? = null
 
     companion object {
         private const val TAG = "MainActivity"
         private const val REQUEST_RECORD_AUDIO = 300
         private const val REQUEST_WRITE_STORAGE = 301
         private const val REQUEST_READ_MEDIA = 302
-        private const val REQUEST_DOWNLOAD_STORAGE = 303
         private const val HOME_URL = "https://agent.cyjai.com"
         private const val WEB_ASSET_VERSION = "20260624_2"
     }
@@ -334,17 +335,6 @@ class MainActivity : AppCompatActivity() {
                     }
                 }
             }
-            REQUEST_DOWNLOAD_STORAGE -> {
-                val url = pendingDownloadUrl
-                val name = pendingDownloadFileName
-                pendingDownloadUrl = null
-                pendingDownloadFileName = null
-                if (url != null && grantResults.isNotEmpty() && grantResults.all { it == PackageManager.PERMISSION_GRANTED }) {
-                    startSystemDownload(url, name ?: suggestFileName(null, url))
-                } else {
-                    Toast.makeText(this, "需要存储权限才能下载文件", Toast.LENGTH_LONG).show()
-                }
-            }
             REQUEST_WRITE_STORAGE, REQUEST_RECORD_AUDIO -> {
                 // 启动时请求的权限，无需额外处理
             }
@@ -529,7 +519,8 @@ class MainActivity : AppCompatActivity() {
         @JavascriptInterface
         fun downloadFile(fileUrl: String?, fileName: String?) {
             val url = fileUrl ?: return
-            val name = fileName ?: suggestFileName(null, url)
+            val name = fileName?.takeIf { it.isNotBlank() }
+                ?: deriveFileName("", null, url)
             runOnUiThread {
                 startSystemDownload(url, name)
             }
@@ -537,67 +528,97 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun startSystemDownload(rawUrl: String, fileName: String) {
-        try {
+        // 不再使用系统 DownloadManager（国产 ROM 上 enqueue 后经常静默失败）。
-            val absoluteUrl = resolveAbsoluteUrl(rawUrl)
+        // 改为应用内下载到私有目录，然后通过系统分享 sheet 让用户选择保存位置。
-            if (absoluteUrl.isBlank()) {
+        lifecycleScope.launch(Dispatchers.IO) {
-                Toast.makeText(this, "下载链接无效", Toast.LENGTH_LONG).show()
-                return
-            }
-
-            // Android 9 及以下需要 WRITE_EXTERNAL_STORAGE 权限才能写入公共下载目录
-            if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P &&
-                ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
-                != PackageManager.PERMISSION_GRANTED
-            ) {
-                pendingDownloadUrl = absoluteUrl
-                pendingDownloadFileName = fileName
-                ActivityCompat.requestPermissions(
-                    this,
-                    arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE),
-                    REQUEST_DOWNLOAD_STORAGE
-                )
-                return
-            }
-
-            val request = buildDownloadRequest(absoluteUrl, fileName)
-            val downloadManager = getSystemService(Context.DOWNLOAD_SERVICE) as DownloadManager
-            downloadManager.enqueue(request)
-            Toast.makeText(this, "已开始下载：$fileName", Toast.LENGTH_SHORT).show()
-        } catch (e: Exception) {
-            Log.e(TAG, "下载失败: ${e.message}", e)
-            Toast.makeText(this, "下载启动失败，请重试", Toast.LENGTH_LONG).show()
-            // 兜底：尝试用浏览器打开
             try {
-                val intent = Intent(Intent.ACTION_VIEW, Uri.parse(resolveAbsoluteUrl(rawUrl)))
+                val absoluteUrl = resolveAbsoluteUrl(rawUrl)
-                startActivity(intent)
+                if (absoluteUrl.isBlank()) {
-            } catch (_: Exception) {}
+                    withContext(Dispatchers.Main) {
+                        Toast.makeText(this@MainActivity, "下载链接无效", Toast.LENGTH_LONG).show()
+                    }
+                    return@launch
+                }
+
+                withContext(Dispatchers.Main) {
+                    Toast.makeText(this@MainActivity, "正在下载：$fileName", Toast.LENGTH_SHORT).show()
+                }
+
+                val downloadedFile = downloadFileToAppDir(absoluteUrl, fileName)
+
+                withContext(Dispatchers.Main) {
+                    shareDownloadedFile(downloadedFile)
+                }
+            } catch (e: Exception) {
+                Log.e(TAG, "下载失败: ${e.message}", e)
+                withContext(Dispatchers.Main) {
+                    Toast.makeText(this@MainActivity, "下载失败：${e.message}", Toast.LENGTH_LONG).show()
+                    // 兜底：尝试用浏览器打开
+                    try {
+                        val intent = Intent(Intent.ACTION_VIEW, Uri.parse(resolveAbsoluteUrl(rawUrl)))
+                        startActivity(intent)
+                    } catch (_: Exception) {}
+                }
+            }
         }
     }
 
-    private fun buildDownloadRequest(url: String, fileName: String): DownloadManager.Request {
+    private fun downloadFileToAppDir(urlString: String, preferredName: String): File {
-        val request = DownloadManager.Request(Uri.parse(url))
+        val dir = File(filesDir, "downloads").apply { mkdirs() }
-            .setTitle(fileName)
+        val connection = URL(urlString).openConnection() as HttpURLConnection
-            .setDescription("正在下载...")
+        connection.connectTimeout = 30000
-            .setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED)
+        connection.readTimeout = 30000
-            .setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI or DownloadManager.Request.NETWORK_MOBILE)
+        connection.instanceFollowRedirects = true
-            .setAllowedOverRoaming(true)
+        connection.setRequestProperty("Cookie", CookieManager.getInstance().getCookie(urlString) ?: "")
-            .setAllowedOverMetered(true)
+        connection.connect()
 
-        // 携带 WebView 中已登录的会话 Cookie，避免下载接口因未登录而 401
+        val finalUrl = connection.url.toString()
-        val cookie = CookieManager.getInstance().getCookie(url)
+        val contentDisposition = connection.getHeaderField("Content-Disposition")
-        if (!cookie.isNullOrBlank()) {
+        val fileName = deriveFileName(preferredName, contentDisposition, finalUrl)
-            request.addRequestHeader("Cookie", cookie)
+
+        val file = File(dir, fileName)
+        connection.inputStream.use { input ->
+            file.outputStream().use { output ->
+                input.copyTo(output)
+            }
         }
+        connection.disconnect()
+        return file
+    }
 
-        return try {
+    private fun shareDownloadedFile(file: File) {
-            request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName)
+        try {
-            request
+            val uri = FileProvider.getUriForFile(this, "${packageName}.fileprovider", file)
+            val mimeType = URLConnection.guessContentTypeFromName(file.name) ?: "application/octet-stream"
+            val intent = Intent(Intent.ACTION_SEND).apply {
+                type = mimeType
+                putExtra(Intent.EXTRA_STREAM, uri)
+                putExtra(Intent.EXTRA_TITLE, file.name)
+                addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            }
+            val chooser = Intent.createChooser(intent, "分享文件").apply {
+                addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            }
+            startActivity(chooser)
+        } catch (e: ActivityNotFoundException) {
+            Toast.makeText(this, "没有可用的文件分享应用", Toast.LENGTH_LONG).show()
         } catch (e: Exception) {
-            Log.w(TAG, "无法指定公共下载目录，使用 DownloadManager 默认位置: ${e.message}")
+            Log.e(TAG, "分享文件失败: ${e.message}", e)
-            request
+            Toast.makeText(this, "分享文件失败：${e.message}", Toast.LENGTH_LONG).show()
         }
     }
 
+    private fun deriveFileName(preferredName: String, contentDisposition: String?, url: String): String {
+        contentDisposition?.let {
+            val regex = Regex("filename\\*?=\\s*\"?([^\";]+)\"?", RegexOption.IGNORE_CASE)
+            regex.find(it)?.groupValues?.get(1)?.trim()?.takeIf { name -> name.isNotBlank() }?.let { return it }
+        }
+        if (preferredName.isNotBlank() && preferredName.contains(".")) return preferredName
+        Uri.parse(url).lastPathSegment?.takeIf { it.isNotBlank() && it.contains(".") }?.let { return it }
+        Uri.parse(url).getQueryParameter("path")?.split("/")?.lastOrNull()?.takeIf { it.isNotBlank() }?.let { return it }
+        return "download_${System.currentTimeMillis()}"
+    }
+
     private fun resolveAbsoluteUrl(rawUrl: String): String {
         if (rawUrl.startsWith("http://") || rawUrl.startsWith("https://")) return rawUrl
         val base = webView.url?.takeIf { it.startsWith("http://") || it.startsWith("https://") } ?: HOME_URL
@@ -608,17 +629,6 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
-    private fun suggestFileName(contentDisposition: String?, url: String): String {
-        contentDisposition?.let {
-            val regex = Regex("filename\\*?=\\s*\"?([^\";]+)\"?", RegexOption.IGNORE_CASE)
-            regex.find(it)?.groupValues?.get(1)?.trim()?.takeIf { name -> name.isNotBlank() }?.let { return it }
-        }
-        val uri = Uri.parse(url)
-        uri.lastPathSegment?.takeIf { it.isNotBlank() && it.contains(".") }?.let { return it }
-        uri.getQueryParameter("path")?.split("/")?.lastOrNull()?.takeIf { it.isNotBlank() }?.let { return it }
-        return "download_${System.currentTimeMillis()}"
-    }
-
     inner class ThemeBridge {
         @JavascriptInterface
         fun onThemeChanged(theme: String?) {

android-webview-app/app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- 应用内部下载目录，用于通过系统分享 sheet 导出文件 -->
+    <files-path name="downloads" path="downloads/" />
+    <cache-path name="cache" path="." />
+</paths>