我试图用相机拍照,但我得到以下错误:

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>

Java:

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);
        }
    }

file_paths.xml

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

我一整天都在搜索这个错误,试图理解FileProvider,但我不知道这个错误消息试图告诉我什么。如果你想要更多信息/代码,请在评论中告诉我。


当前回答

我做了什么来解决这个问题

AndroidManifest.xml

<provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="com.mydomain.fileprovider"
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/filepaths"/>
        </provider>

fileppaths .xml(允许FileProvider共享应用程序外部文件目录中的所有文件)

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-files-path name="files"
        path="/" />
</paths>

并在Java类-

Uri fileProvider = FileProvider.getUriForFile(getContext(),"com.mydomain.fileprovider",newFile);

其他回答

请注意,external-path不是指向二级存储,即“可移动存储”(尽管名称为“external”)。如果你得到“未能找到配置的根”,你可以将这一行添加到你的XML文件中。

<root-path name="root" path="." />

更多细节请参见FileProvider和次要外部存储

Android官方文档说file_paths.xml应该有:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">   
    <external-path name="my_images"    
        path="Android/data/com.example.package.name/files/Pictures" />
</paths>

但是为了让它在最新的android中工作,在路径的末尾应该有一个“/”,就像这样:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">   
    <external-path name="my_images"    
        path="Android/data/com.example.package.name/files/Pictures/" />
</paths>

您的文件存储在getExternalFilesDir()下。它映射到<external-files-path>,而不是<files-path>。此外,您的文件路径中不包含图像/,因此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>

更新 2020 3月 13

特定路径的提供者路径如下:

<files-path/>——> <cache-path/>——> <external-path/>——> Environment.getExternalStorageDirectory() <external-files-path/>——> Context.getExternalFilesDir(String) <external-cache-path/>——> Context.getExternalCacheDir() <external-media-path/>——> Context.getExternalMediaDirs()

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

这些对我都没用。唯一可行的方法是不要在xml中声明显式路径。所以,这样做吧,快乐起来:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="my_images" path="." />
</paths>

这里也有一个关于这个问题的优秀教程: https://www.youtube.com/watch?v=9ZxRTKvtfnY&t=613s

以上这些方法对我都没用, 经过几个小时的调试,我发现问题在createImageFile(),特别是绝对路径与相对路径

我猜你们使用的是官方的Android拍照指南。https://developer.android.com/training/camera/photobasics

    private static File createImageFile(Context context) throws IOException {
        // Create an image file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String imageFileName = "JPEG_" + timeStamp + "_";
        File storageDir = context.getExternalFilesDir(Environment.DIRECTORY_PICTURES);
        File image = File.createTempFile(
                imageFileName,  /* prefix */
                ".jpg",         /* suffix */
                storageDir      /* directory */
        );

        // Save a file: path for use with ACTION_VIEW intents
        mCurrentPhotoPath = image.getAbsolutePath();
        return image;
    }

请注意storageDir,这是将创建文件的位置。所以为了获得这个文件的绝对路径,我简单地使用image. getabsolutepath(),这个路径将在onActivityResult中使用,如果你需要拍摄照片后的位图图像

下面是file_path.xml文件,简单使用即可。所以它使用了绝对路径

<paths>
    <external-path
        name="my_images"
        path="." />
</paths>

以及拍照后是否需要位图

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        Bitmap bmp = null;
        try {
            bmp = BitmapFactory.decodeFile(mCurrentPhotoPath);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }