c# - 从内部存储中查找文档的文件路径

Question

我正在创建一个应用程序，允许您从设备中选择文件并将它们作为附件附加到 MailMessage 对象。使用以下代码，我已经能够从设备中获取图像的内容 uri，然后使用它以字符串形式提供文件路径。我将如何交替使用此代码以处理 .doc/.docx/pdf 文件类型？

{
        string filePath = null;
        Uri _uri = data.Data;
        if (_uri != null && "content".Equals(_uri.Scheme))
        {
            ICursor cursor = this.ContentResolver.Query(_uri, new String[] { Android.Provider.MediaStore.Images.ImageColumns.Data }, null, null, null);
            cursor.MoveToFirst();
            filePath = cursor.GetString(0);
            cursor.Close();
        }
        else
        {
            filePath = _uri.Path;
        }
        return filePath;
    }

Answer 1

你可以试试getPath

public class Uris {

    private static String getFileName(Context context, Uri uri) {
        String result = null;
        if (uri.getScheme().equals("content")) {
            Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
            try {
                if (cursor != null && cursor.moveToFirst()) {
                    result = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
                }
            } finally {
                cursor.close();
            }
        }
        if (result == null) {
            result = uri.getPath();
            int cut = result.lastIndexOf('/');
            if (cut != -1) {
                result = result.substring(cut + 1);
            }
        }
        return result;
    }




    @TargetApi(Build.VERSION_CODES.KITKAT)
    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];
            }
        }
        // DownloadsProvider
        else if (isDownloadsDocument(uri)) {
/*
            final String id = DocumentsContract.getDocumentId(uri);
            final Uri contentUri = ContentUris.withAppendedId(
                    Uri.parse("content://<span id=\"IL_AD1\" class=\"IL_AD\">downloads</span>/public_downloads"), Long.valueOf(id));
            return getDataColumn(context, contentUri, null, null);
*/
            String fileName = getFileName(context, uri);
            File downFile = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), "/"+fileName);
            return downFile.getAbsolutePath();
        }
        // 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;
}

    /**
     * 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 index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(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());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is Google <span id="IL_AD8" class="IL_AD">Photos</span>.
     */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }

}