Question

我正在尝试使用Intent.ACTION_GET_CONTENT打开文件。

根据Android版本/设备品牌，文件浏览器打开，我得到以下结果：

从Downloads选择文件：

content://com.android.providers.downloads.documents/document/446

从Fotos选择文件：

content://media/external/images/media/309

从FileCommander选择文件：

file:///storage/emulated/0/DCIM/Camera/20141027_132114.jpg

我可以打开所有这些文件，除非我尝试从Downloads,，Audio，Afbeeldingen（图片）打开文件

我可能无法处理这种Uri：content://com.android.providers.downloads.documents/document/446

我尝试了以下事项：

尝试通过新文件（uri.getPath（））打开文件。 File.exists（）返回false。
尝试通过getContext（）。getContentResolver（）。openInputStream（uri）打开/访问该文件。结果进入FileNotFoundException

尝试使用以下代码打开文件：

public static String getRealPathFromURI_API19(Context context, Uri uri) {

Log.i("uri", uri.getPath());
String filePath = "";
if (uri.getScheme().equals("file")) {
    return uri.getPath();
} else if (DocumentsContract.isDocumentUri(context, uri)) {
    String wholeID = DocumentsContract.getDocumentId(uri);
    Log.i("wholeID", wholeID);
    // Split at colon, use second item in the array
    String[] splits = wholeID.split(":");
if (splits.length == 2) {
    String id = splits[1];

        String[] column = {MediaStore.Images.Media.DATA};
    // where id is equal to
        String sel = MediaStore.Images.Media._ID + "=?";
        Cursor cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                column, sel, new String[]{id}, null);
        int columnIndex = cursor.getColumnIndex(column[0]);
        if (cursor.moveToFirst()) {
            filePath = cursor.getString(columnIndex);
        }
        cursor.close();
    }
} else {
    filePath = AttachmentUtils.getPath(context, uri);
}
return filePath;
}

我做错了什么？

更新：我注意到屏幕截图中列出的文件实际上并不存在于存储中。我使用的设备是包含垃圾数据的公司平板电脑。我的同事告诉我，此设备曾与其他Google帐户关联。这些文件可能是以前帐户中不再存在/可访问的文件。

我自己的结论是我在Android中遇到了一些错误。我的bug report

2017年2月6日更新：

Android禁止使用file:// URI。请考虑考虑一下。

Ban on file：Uri Scheme迄今为止最大的兼容性问题 Android 7.0是禁止Uri值的文件：scheme 影响。如果您尝试传递文件：Uri正在进行的Intent中到另一个应用程序 - 无论是通过额外的或作为“数据”方面的意图 - 您将因FileUriExposedException异常而崩溃。您将文件放在Uri值上会遇到类似的问题 ClipData中的剪贴板。这是来自更新版本严格模式。 StrictMode.VmPolicy.Builder有一个 penaltyDeathOnFileUriExposure（）方法触发检测 file：Uri值和生成的FileUriExposedException异常。并且，它似乎是预先配置的，就像StrictMode一样预先配置为应用penaltyDeathOnNetwork（）（你的来源） NetworkOnMainThreadException崩溃）。

Answer 1

使用以下代码。这肯定会有用。

public static String getPath(Context context, Uri uri) {
    final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

    // DocumentProvider
    if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
        // ExternalStorageProvider
        if (isExternalStorageDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            if ("primary".equalsIgnoreCase(type)) {
                return Environment.getExternalStorageDirectory() + "/" + split[1];
            }
            // TODO handle non-primary volumes
        }
        // DownloadsProvider
        else if (isDownloadsDocument(uri)) {
            final String id = DocumentsContract.getDocumentId(uri);
            final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
            return getDataColumn(context, contentUri, null, null);
        }
        // MediaProvider
        else
        if (isMediaDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];
            Uri contentUri = null;
            if ("image".equals(type)) {
                contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
            } else if ("video".equals(type)) {
                contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
            } else if ("audio".equals(type)) {
                contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
            }
            final String selection = "_id=?";
            final String[] selectionArgs = new String[] {split[1]};
            return getDataColumn(context, contentUri, selection, selectionArgs);
        }
    }
    // MediaStore (and general)
    else if ("content".equalsIgnoreCase(uri.getScheme())) {
        // Return the remote address
        if (isGooglePhotosUri(uri))
            return uri.getLastPathSegment();
        return getDataColumn(context, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }
    return null;
}

public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
    Cursor cursor = null;
    final String column = "_data";
    final String[] projection = { column };
    try {
        cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
        if (cursor != null && cursor.moveToFirst()) {
            final int index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}

public static boolean isExternalStorageDocument(Uri uri) {
    return "com.android.externalstorage.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is DownloadsProvider.
 */
public static boolean isDownloadsDocument(Uri uri) {
    return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is MediaProvider.
 */
public static boolean isMediaDocument(Uri uri) {
    return "com.android.providers.media.documents".equals(uri.getAuthority());
}

/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is Google Photos.
 */
public static boolean isGooglePhotosUri(Uri uri) {
    return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}

使用以下代码以任何格式浏览文件。

public void browseClick() {

    Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
    intent.setType("*/*");
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    //intent.putExtra("browseCoa", itemToBrowse);
    //Intent chooser = Intent.createChooser(intent, "Select a File to Upload");
    try {
        //startActivityForResult(chooser, FILE_SELECT_CODE);
        startActivityForResult(Intent.createChooser(intent, "Select a File to Upload"),FILE_SELECT_CODE);
    } catch (Exception ex) {
        System.out.println("browseClick :"+ex);//android.content.ActivityNotFoundException ex
    }
}

然后在onActivityResult中获取该文件路径，如下所示。

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == FILE_SELECT_CODE) {
        if (resultCode == RESULT_OK) {
            try {
              Uri uri = data.getData();

                if (filesize >= FILE_SIZE_LIMIT) {
                    Toast.makeText(this,"The selected file is too large. Selet a new file with size less than 2mb",Toast.LENGTH_LONG).show();
                } else {
                    String mimeType = getContentResolver().getType(uri);
                    if (mimeType == null) {
                        String path = getPath(this, uri);
                        if (path == null) {
                            filename = FilenameUtils.getName(uri.toString());
                        } else {
                            File file = new File(path);
                            filename = file.getName();
                        }
                    } else {
                        Uri returnUri = data.getData();
                        Cursor returnCursor = getContentResolver().query(returnUri, null, null, null, null);
                        int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
                        int sizeIndex = returnCursor.getColumnIndex(OpenableColumns.SIZE);
                        returnCursor.moveToFirst();
                        filename = returnCursor.getString(nameIndex);
                        String size = Long.toString(returnCursor.getLong(sizeIndex));
                    }
   File fileSave = getExternalFilesDir(null);
    String sourcePath = getExternalFilesDir(null).toString();
    try {
                        copyFileStream(new File(sourcePath + "/" + filename), uri,this);

                    } catch (Exception e) {
                        e.printStackTrace();
                    }
  }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}
private void copyFileStream(File dest, Uri uri, Context context)
        throws IOException {
    InputStream is = null;
    OutputStream os = null;
    try {
        is = context.getContentResolver().openInputStream(uri);
        os = new FileOutputStream(dest);
        byte[] buffer = new byte[1024];
        int length;

        while ((length = is.read(buffer)) > 0) {
            os.write(buffer, 0, length);

        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        is.close();
        os.close();
    }
}

在此之后，您可以从应用程序外部存储中打开此文件，并使用适当的操作保存文件。

Answer 2

科特琳接受的答案

@Suppress("SpellCheckingInspection")
object PathCompat {

    @WorkerThread
    fun getFilePath(context: Context, uri: Uri): String? = context.run {
        return try {
            when {
                Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT -> getDataColumn(uri, null, null)
                else -> getPathKitkatPlus(uri)
            }
        } catch (e: Throwable) {
            Timber.e(e)
            null
        }
    }

    @Suppress("DEPRECATION")
    @SuppressLint("NewApi", "DefaultLocale")
    private fun Context.getPathKitkatPlus(uri: Uri): String? {
        when {
            DocumentsContract.isDocumentUri(applicationContext, uri) -> {
                val docId = DocumentsContract.getDocumentId(uri)
                when {
                    uri.isExternalStorageDocument -> {
                        val parts = docId.split(":")
                        if ("primary".equals(parts[0], true)) {
                            return "${Environment.getExternalStorageDirectory()}/${parts[1]}"
                        }
                    }
                    uri.isDownloadsDocument -> {
                        val contentUri = ContentUris.withAppendedId(
                            Uri.parse("content://downloads/public_downloads"),
                            docId.toLong()
                        )
                        return getDataColumn(contentUri, null, null)
                    }
                    uri.isMediaDocument -> {
                        val parts = docId.split(":")
                        val contentUri = when (parts[0].toLowerCase()) {
                            "image" -> MediaStore.Images.Media.EXTERNAL_CONTENT_URI
                            "video" -> MediaStore.Video.Media.EXTERNAL_CONTENT_URI
                            "audio" -> MediaStore.Audio.Media.EXTERNAL_CONTENT_URI
                            else -> return null
                        }
                        return getDataColumn(contentUri, "_id=?", arrayOf(parts[1]))
                    }
                }
            }
            "content".equals(uri.scheme, true) -> {
                return if (uri.isGooglePhotosUri) {
                    uri.lastPathSegment
                } else {
                    getDataColumn(uri, null, null)
                }
            }
            "file".equals(uri.scheme, true) -> {
                return uri.path
            }
        }
        return null
    }

    private fun Context.getDataColumn(uri: Uri, selection: String?, args: Array<String>?): String? {
        contentResolver?.query(uri, arrayOf("_data"), selection, args, null)?.use {
            if (it.moveToFirst()) {
                return it.getString(it.getColumnIndexOrThrow("_data"))
            }
        }
        return null
    }

    private val Uri.isExternalStorageDocument: Boolean
        get() = authority == "com.android.externalstorage.documents"

    private val Uri.isDownloadsDocument: Boolean
        get() = authority == "com.android.providers.downloads.documents"

    private val Uri.isMediaDocument: Boolean
        get() = authority == "com.android.providers.media.documents"

    private val Uri.isGooglePhotosUri: Boolean
        get() = authority == "com.google.android.apps.photos.content"
}

Answer 3

我刚刚遇到了一个错误

final String docId = DocumentsContract.getDocumentId(uri);

返回不同的URI（例如：content://com.android.providers.downloads.documents/document/11 有时content://com.android.providers.downloads.documents/document/abc%aile.jpg在这种情况下Long.valueOf(id)抛出异常来解决

String id = DocumentsContract.getDocumentId(uri);
                if (id.startsWith("raw:")) {
                    id = id.replaceFirst("raw:", "");
                    return id;
                }
                final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(contentUri, null, null);

这样做返回ID，对我有用

Answer 4

使用系统文件选择器选择任何文件：

val intent = Intent(Intent.ACTION_GET_CONTENT)
intent.type = "*/*"
startActivityForResult(intent, 1)

onActivityResult：

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == 1 && resultCode == Activity.RESULT_OK) {
        data?.data?.let {
            getFileFromUri(requireContext().contentResolver, uri, requireContext().cacheDir)
        }
    }
}

获取文件：

private fun getFileFromUri(contentResolver: ContentResolver, uri: Uri, directory: File): File {
    val file =
        File.createTempFile("suffix", "prefix", directory)
    file.outputStream().use {
        contentResolver.openInputStream(uri)?.copyTo(it)
    }

    return file
}

Android使用ACTION_GET_CONTENT打开文件会导致不同的Uri

2017年2月6日更新：

4 个答案: