Question

我正在考虑将LiteDb用于C＃作为文档存储系统。

只要我知道文件的ID，我就可以上传和下载 - 但我也希望能够选择搜索它。

LiteDb文档提供了此命令，用于搜索存储在特定＆＃39;目录中的所有文件。在Db内;

echo 'export PATH="$HOME/.composer/vender/bin:$PATH"' >> ~/.bashrc

但是，我无法弄清楚如何处理files变量。我无法将其转换为可用的字符串等。

我想将它添加到listview中。例如。

有没有人有使用LiteDb和文件搜索的经验？

Answer 1

回答得有点晚，但是它可能仍然有用。搜索文件的更好方法是访问“ _files”集合，该集合将使您可以搜索文件的元数据：

class _files
{
    public string Id { get; set; }
    public string filename { get; set; }
    public string mimeType { get; set; }
    public long length { get; set; }
    public int chunks{ get; set; }
    public DateTime uploadDate { get; set; }
    public object metadata { get; set; } //You could replace object with a custom class
}

然后可以使用“ _files”类访问文件信息以进行搜索。在这种情况下，它将检索文件名中带有“ somefile”的所有文件：

var files = new LiteDatabase("myDatabase.db")
    .GetCollection<_files>() //Accesses the _files collection where file info is stored
    .Find(file => file.Filename.Contains("somefile")); //Find files with "somefile" in the filename

然后您可以遍历结果以访问文件的信息：

foreach(var searchResult in files)
{
    var fileInfo = $"Id: {searchResult.Id} | Filename: {searchResult.filename} | Length: {searchResult.length}";
    Console.WriteLine(fileInfo);
}

这将输出类似于：

Id: file1 | Filename: important.doc | Length: 73453
Id: file2 | Filename: less_important.doc | Length: 3476

此外，不要忘记为经常搜索的属性创建索引。例如，在上面的示例中，我搜索了文件名。我可以为filename属性创建一个索引，如下所示：

new LiteDatabase("myDatabase.db")
    .GetCollection<_files>()
    .EnsureIndex(files => files.filename); //Create an index for filename

Answer 2

我设法解决了问题....如果对其他人有用，我会分享。

 listView1.Items.Clear();
        try
        {
    //"" is a blank search which will return all files. 
    //But could easily be a value from a textbox. It is loaded into the Array Files

            var files = db.FileStorage.Find("").ToArray();

    //go through each obj in the array and abstract FileName, ID and 
    //Created date, adding them each to a new array (mylist, mylist1 etc.)
foreach (object obj in files)
            {

                mylist = files.Select(I => Convert.ToString(I.Filename)).ToArray();
                mylist1 = files.Select(I => Convert.ToString(I.UploadDate)).ToArray();
                mylist2 = files.Select(I => Convert.ToString(I.Id)).ToArray();


            }

 //loop through the mylist arrays an create usable strings for each value.
            for (int i = 0; i < mylist.Length; i++)
            {
                name = mylist[i].ToString();
                datecreated = mylist1[i].ToString();
                id = mylist2[i].ToString();
 //add each value to a listview
                listView1.Items.Add(new ListViewItem(new string[] { name, datecreated,id }));

            }

Answer 3

我有一种更简单的上传文件的方式，例如，如果要将用户的个人资料照片上传到LiteDB，则我为文档和文件使用相同的ID。为此，我首先创建一个新的ObjectID。然后，我得到图片并以fileId作为我刚创建的ID上载。为了验证我是否确实上传了文件，我将其下载到特殊目录文件夹中的本地文件夹中。然后，我获取本地文件夹的filePath并将其保存为“用户配置文件”文档的一部分。因此，一旦用用户填充了视图，就可以使用ID从本地目录或直接从LiteDB中检索文件。

您可以访问我的YouTube频道，以获取有关LiteDB的完整教程：https://www.youtube.com/watch?v=fiwJ0XkHIZg 或

您可以从我的GitHub存储库中获取完整的源代码：https://github.com/Parables/CMS。

以下是一些可以从LiteDB上传，查找和删除文件的功能：

    #Region "Set Profile Picture"
    Private Sub pbxPicture_Click(sender As Object, e As EventArgs) Handles pbxPicture.Click
        With OpenFileDialog1
            .AddExtension = True
            .CheckFileExists = True
            .CheckPathExists = True
            .Multiselect = False
            .ShowDialog()
            .Title = "Select a picture for the Member"
        End With
    End Sub

    Private Sub OpenFileDialog1_FileOk(sender As Object, e As System.ComponentModel.CancelEventArgs) Handles OpenFileDialog1.FileOk
        Dim ofdFileName As String = OpenFileDialog1.FileName.ToString
        Try
            FindPhoto(UploadImage(ofdFileName))
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try

        ' DeleteUploadedImage(picName)
    End Sub

#End Region

#Region "Picture Upload, Find and Delete"
    Dim uploadURL As String = ""
    Dim downloadURL As String = ""
    Private Function UploadImage(fileName) As String
        Try
            Dim db As New LiteDatabase(CMSDB)
            uploadURL = $"{MembersPhotoStorage}{ID}"
            db.FileStorage.Upload(uploadURL, fileName)
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        Return uploadURL
    End Function

    Private Function FindPhoto(FileID As String) As String
        Dim File As LiteFileInfo = Nothing
Try
            Dim db As New LiteDatabase(CMSDB)
            File = db.FileStorage.FindById(FileID)
            My.Computer.FileSystem.CreateDirectory(MembersPhotoDir)
            downloadURL = $"{MembersPhotoDir}{ID}.png"
            File.SaveAs(downloadURL, True)
            pbxPicture.ImageLocation = downloadURL
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        Return downloadURL
    End Function

    Private Sub DeleteUploadedImage()
        Try
            Dim db As New LiteDatabase(CMSDB)
            db.FileStorage.Delete($"{MembersPhotoStorage}{ID}")
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub
#End Region

LiteDb - 文件存储搜索

3 个答案: