在Android 4.4 (KitKat)的新图库访问之前,我用这个方法在SD卡上获得了我的真实路径:

public String getPath(Uri uri) {
   String[] projection = { MediaStore.Images.Media.DATA };
   Cursor cursor = managedQuery(uri, projection, null, null, null);
   startManagingCursor(cursor);
   int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
   cursor.moveToFirst();
 return cursor.getString(column_index);
}

现在来看意图。ACTION_GET_CONTENT返回不同的数据:

之前:

content://media/external/images/media/62

Now:

content://com.android.providers.media.documents/document/image:62

我怎样才能获得SD卡上的真实路径?


当前回答

这将从MediaProvider、DownloadsProvider和ExternalStorageProvider获取文件路径,同时回落到您提到的非官方的ContentProvider方法。

/**
 * Get a file path from a Uri. This will get the the path for Storage Access
 * Framework Documents, as well as the _data field for the MediaStore and
 * other file-based ContentProviders.
 *
 * @param context The context.
 * @param uri The Uri to query.
 * @author paulburke
 */
public static String getPath(final Context context, final 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 getDataColumn(context, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
}

/**
 * Get the value of the data column for this Uri. This is useful for
 * MediaStore Uris, and other file-based ContentProviders.
 *
 * @param context The context.
 * @param uri The Uri to query.
 * @param selection (Optional) Filter used in the query.
 * @param selectionArgs (Optional) Selection arguments used in the query.
 * @return The value of the _data column, which is typically a file path.
 */
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 column_index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(column_index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}


/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is ExternalStorageProvider.
 */
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());
}

这些是从我的开源库aFileChooser中截取的。

其他回答

注意:这个答案解决了部分问题。要获得完整的解决方案(以库的形式),请参阅Paul Burke的答案。

您可以使用URI获取文档id,然后查询MediaStore.Images.Media。EXTERNAL_CONTENT_URI或MediaStore.Images.Media。INTERNAL_CONTENT_URI(取决于SD卡的情况)。

获取文档id:

// Will return "image:x*"
String wholeID = DocumentsContract.getDocumentId(uriThatYouCurrentlyHave);

// Split at colon, use second item in the array
String id = wholeID.split(":")[1];

String[] column = { MediaStore.Images.Media.DATA };     

// where id is equal to             
String sel = MediaStore.Images.Media._ID + "=?";

Cursor cursor = getContentResolver().
                          query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, 
                          column, sel, new String[]{ id }, null);

String filePath = "";

int columnIndex = cursor.getColumnIndex(column[0]);

if (cursor.moveToFirst()) {
    filePath = cursor.getString(columnIndex);
}   

cursor.close();

参考:我找不到这个解决方案的帖子。我想请原海报在这里投稿。今晚会再看看。

试试这个:

//KITKAT
i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, CHOOSE_IMAGE_REQUEST);

在onActivityResult中使用以下命令:

Uri selectedImageURI = data.getData();
input = c.getContentResolver().openInputStream(selectedImageURI);
BitmapFactory.decodeStream(input , null, opts);

在奇巧的新画廊访问之前,我用这种方法在sdcard中获得了我的真实路径

这从来都不可靠。不要求从ACTION_GET_CONTENT或ACTION_PICK请求返回的Uri必须由MediaStore索引,甚至必须表示文件系统上的一个文件。例如,Uri可以表示一个流,其中加密的文件会为您动态解密。

我怎么能设法获得真正的路径在sdcard?

不需要有一个与Uri对应的文件。

是的,我真的需要一条路

然后将该文件从流复制到您自己的临时文件,并使用它。更好的方法是直接使用流,避免使用临时文件。

我已经改变了我的意图。ACTION_GET_CONTENT for Intent。ACTION_PICK

这对你的处境没有帮助。没有要求ACTION_PICK响应是针对文件系统上有一个可以神奇地派生的文件的Uri。

以下是保罗·伯克的回答的更新版本。在Android 4.4 (KitKat)以下的版本中,我们没有DocumentsContract类。

为了在KitKat以下的版本上工作,创建这个类:

public class DocumentsContract {
    private static final String DOCUMENT_URIS =
        "com.android.providers.media.documents " +
        "com.android.externalstorage.documents " +
        "com.android.providers.downloads.documents " +
        "com.android.providers.media.documents";

    private static final String PATH_DOCUMENT = "document";
    private static final String TAG = DocumentsContract.class.getSimpleName();

    public static String getDocumentId(Uri documentUri) {
        final List<String> paths = documentUri.getPathSegments();
        if (paths.size() < 2) {
            throw new IllegalArgumentException("Not a document: " + documentUri);
        }

        if (!PATH_DOCUMENT.equals(paths.get(0))) {
            throw new IllegalArgumentException("Not a document: " + documentUri);
        }
        return paths.get(1);
    }

    public static boolean isDocumentUri(Uri uri) {
        final List<String> paths = uri.getPathSegments();
        Logger.v(TAG, "paths[" + paths + "]");
        if (paths.size() < 2) {
            return false;
        }
        if (!PATH_DOCUMENT.equals(paths.get(0))) {
            return false;
        }
        return DOCUMENT_URIS.contains(uri.getAuthority());
    }
}

这将从MediaProvider、DownloadsProvider和ExternalStorageProvider获取文件路径,同时回落到您提到的非官方的ContentProvider方法。

/**
 * Get a file path from a Uri. This will get the the path for Storage Access
 * Framework Documents, as well as the _data field for the MediaStore and
 * other file-based ContentProviders.
 *
 * @param context The context.
 * @param uri The Uri to query.
 * @author paulburke
 */
public static String getPath(final Context context, final 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 getDataColumn(context, uri, null, null);
    }
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
}

/**
 * Get the value of the data column for this Uri. This is useful for
 * MediaStore Uris, and other file-based ContentProviders.
 *
 * @param context The context.
 * @param uri The Uri to query.
 * @param selection (Optional) Filter used in the query.
 * @param selectionArgs (Optional) Selection arguments used in the query.
 * @return The value of the _data column, which is typically a file path.
 */
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 column_index = cursor.getColumnIndexOrThrow(column);
            return cursor.getString(column_index);
        }
    } finally {
        if (cursor != null)
            cursor.close();
    }
    return null;
}


/**
 * @param uri The Uri to check.
 * @return Whether the Uri authority is ExternalStorageProvider.
 */
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());
}

这些是从我的开源库aFileChooser中截取的。