android - 从 Android Kitkat 中的 Uri 获取路径抛出非法参数异常

Question

我正在尝试从 uri 获取路径。它适用于 kitkat 以下的设备。我用谷歌搜索，发现我需要获取文档 ID，然后使用图库项目查询它。它有效。但是我在视频方面遇到了问题。当我从视频部分选择视频时，它起作用了。但是当我从图库中选择它时，我的应用程序崩溃，给出非法参数异常 - 不是文档类型。我知道为什么会这样。这是因为我正在画廊部分寻找文档类型的视频。但是如何防止这种情况。这样我就可以从图库和视频部分中选择视频。

这是我的代码:

public static String getRealPathFromURI(Context context, Uri contentUri,String type) {
    if(isKitkatBelow()) {
        String[] proj = { MediaStore.Images.Media.DATA };
        Cursor cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
        int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }else{

        String docId= DocumentsContract.getDocumentId(contentUri);
        String id=  docId.split(":")[1];
        if(type== TYPE_IMAGE){
            String[] proj = { MediaStore.Images.Media.DATA };
            String whereClause=MediaStore.Images.Media._ID + "=?";
            Cursor cursor=context.getContentResolver().query(getUri(type),proj,whereClause,new String[]{id},null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }else{
            String[] proj = { MediaStore.Video.Media.DATA };
            String whereClause=MediaStore.Video.Media._ID + "=?";
            Cursor cursor=context.getContentResolver().query(getUri(type),proj,whereClause,new String[]{id},null);
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA);
            cursor.moveToFirst();
            return cursor.getString(column_index);
        }



    }
}

发生这种情况是因为我正在尝试在图库中搜索类型为 MediaStore.Video.Media.DATA 的文件。但是对于低于 kitkat 的设备，MediaStore.Images.Media.DATA 也从图库中获取视频 uri，而不会导致任何崩溃。提前致谢..

Answer 1

您可以使用从所选文件的 Uri 获取绝对路径，因为 KitKat(API 19)和 Android 中的 Kitkat 之间存在差异，可以使用以下代码实现此目的，

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());
}