FileProvider - IllegalArgumentException：找不到配置的根

Question

我正在尝试用相机拍照，但出现以下错误：

 FATAL EXCEPTION: main
Process: com.example.marek.myapplication, PID: 6747
java.lang.IllegalArgumentException: Failed to find configured root that contains /storage/emulated/0/Android/data/com.example.marek.myapplication/files/Pictures/JPEG_20170228_175633_470124220.jpg
    at android.support.v4.content.FileProvider$SimplePathStrategy.getUriForFile(FileProvider.java:711)
    at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:400)
    at com.example.marek.myapplication.MainActivity.dispatchTakePictureIntent(MainActivity.java:56)
    at com.example.marek.myapplication.MainActivity.access$100(MainActivity.java:22)
    at com.example.marek.myapplication.MainActivity$1.onClick(MainActivity.java:35)

AndroidManifest.xml：

 <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="com.example.marek.myapplication.fileprovider"
        android:enabled="true"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/file_paths" />
</provider>

爪哇：

 Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        // Create the File where the photo should go
        File photoFile = null;
        try {
            photoFile = createImageFile();
        } catch (IOException ex) {
            Toast.makeText(getApplicationContext(), "Error while saving picture.", Toast.LENGTH_LONG).show();
        }
        // Continue only if the File was successfully created
        if (photoFile != null) {
            Uri photoURI = FileProvider.getUriForFile(this,
                    "com.example.marek.myapplication.fileprovider",
                    photoFile);
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
        }
    }

文件路径.xml

 <?xml version="1.0" encoding="utf-8"?>
<paths>
    <files-path name="my_images" path="images/"/>
</paths>

我整天都在搜索这个错误并试图理解 FileProvider ，但我不知道这个错误消息试图告诉我什么。如果您需要更多信息/代码，请在评论中写信给我。

原文由 Pivoman 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

您的文件存储在 getExternalFilesDir() 下。这映射到 <external-files-path> ，而不是 <files-path> 。此外，您的文件路径中不包含 images/ ，因此您的 XML 中的 path 属性无效。

将 res/xml/file_paths.xml 替换为：

 <?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-files-path name="my_images" path="/" />
</paths>

---

2020 年 3 月 13 日更新

具体路径的提供者路径如下：

• <files-path/> –> Context.getFilesDir()
• <cache-path/> –> Context.getCacheDir()
• <external-path/> –> Environment.getExternalStorageDirectory()
• <external-files-path/> –> Context.getExternalFilesDir(String)
• <external-cache-path/> –> Context.getExternalCacheDir()
• <external-media-path/> –> Context.getExternalMediaDirs()

参考： https ://developer.android.com/reference/androidx/core/content/FileProvider

原文由 CommonsWare 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

@CommonsWare 的答案很棒。

但就我而言，我必须添加多个路径。

 <?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-path name="external_files" path="." />
    <files-path name="external_files" path="." />
</paths>

原文由 Thiago 发布，翻译遵循 CC BY-SA 4.0 许可协议