Flutter使用share_plus分享网络图片遇PlatformException问题求助

问题 #

我想通过share_plus插件的shareFiles方法分享一张来自URL的图片，代码如下：

final url = Uri.parse(url);
final response = await http.get(url);
final bytes = response.bodyBytes;

final directory = await getTemporaryDirectory();
final file = File('${directory.path}/tempp.png');
await file.writeAsBytes(bytes);

print(file.path);

await Share.shareFiles([file.path]);

运行时抛出异常：

PlatformException (PlatformException(error, Failed to find configured root that contains /storage/emulated/0/Android/data/mrblab.news_app/cache/share/tempp.png, null, java.lang.IllegalArgumentException: Failed to find configured root that contains /storage/emulated/0/Android/data/mrblab.news_app/cache/share/tempp.png
    at androidx.core.content.FileProvider$SimplePathStrategy.getUriForFile(FileProvider.java:825)
    at androidx.core.content.FileProvider.getUriForFile(FileProvider.java:450)
    at io.flutter.plugins.share.Share.getUrisForPaths(Share.java:128)
    at io.flutter.plugins.share.Share.shareFiles(Share.java:69)
    at io.flutter.plugins.share.MethodCallHandler.onMethodCall(MethodCallHandler.java:42)
    at io.flutter.plugin.common.MethodChannel$IncomingMethodCallHandler.onMessage(MethodChannel.java:258)
    at io.flutter.embedding.engine.dart.DartMessenger.invokeHandler(DartMessenger.java:295)
    at io.flutter.embedding.engine.dart.DartMessenger.lambda$dispatchMessageToQueue$0$io-flutter-embedding-engine-dart-DartMessenger(DartMessenger.java:322)
    at io.flutter.embedding.engine.dart.DartMessenger$$ExternalSyntheticLambda0.run(Unknown Source:12)
    at android.os.Handler.handleCallback(Handler.java:984)
    at android.os.Handler.dispatchMessage(Handler.java:104)
    at android.os.Looper.loopOnce(Looper.java:238)
    at android.os.Looper.loop(Looper.java:357)
    at android.app.ActivityThread.main(ActivityThread.java:8149)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:957)
))

已在AndroidManifest.xml中配置了READ和WRITE权限，并且创建了provider_paths.xml：

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <cache-path
        name="share"
        path="." />
</paths>

请问该如何解决这个问题？

解决方案 #

这个问题核心是FileProvider的路径配置与实际文件路径不匹配，按以下步骤修复：

• 修正provider_paths.xml的路径配置
  异常显示文件实际路径是/storage/emulated/0/Android/data/mrblab.news_app/cache/share/tempp.png，说明文件存放在缓存目录下的share子文件夹，但当前cache-path的path="."仅指向缓存根目录。修改配置：

  <?xml version="1.0" encoding="utf-8"?>
  <paths>
      <cache-path
          name="share"
          path="share/" />
  </paths>
  

  若代码中并未主动创建share子目录，可能是插件内部自动添加了该路径，此时也可以调整代码里的文件保存路径，直接存到缓存根目录：

  final file = File('${directory.path}/tempp.png');
  

• 确认AndroidManifest.xml的FileProvider配置正确
  确保provider的android:authorities为应用包名加.fileprovider，且关联了正确的provider_paths.xml：

  <application>
      ...
      <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/provider_paths" />
      </provider>
  </application>
  

• 清理并重建项目
  修改配置后执行flutter clean，再重新运行项目，避免旧配置缓存导致问题。

另外，Android 10及以上版本启用了Scoped Storage，WRITE_EXTERNAL_STORAGE权限已不再需要，可移除该权限以简化配置。

内容的提问来源于stack exchange，提问作者Saya