Question

如果有人可以帮助我，我很好奇吗？

我有一个应用程序，假设上传/下载数据到表。将数据写入表格没问题。阅读就是问题所在。

这就是我所拥有的：

首先是我的班级：

Imports Microsoft.WindowsAzure.Storage.Table

Public Class TimeRecord
Inherits Microsoft.WindowsAzure.Storage.Table.TableEntity
Implements Microsoft.WindowsAzure.Storage.Table.ITableEntity

Private _Project1 As String

Public Property Project1 As String
    Get
        Return _Project1
    End Get
    Set(ByVal value As String)
        _Project1 = value
    End Set
End Property


Public Property Data As String
Public Property Category1 As String
Public Property Description1 As String
Public Property HRS1 As String
Public Property MINS1 As String

Public Property Project2 As String
Public Property Category2 As String
Public Property Description2 As String
Public Property HRS2 As String
Public Property MINS2 As String


end class

'next is the Upload, which is working fine and uploading all data to the table

Public NewRecord As New TimeRecord
Public CloudNewRecord As New TimeRecord

' Finishing and uploading
Private Sub Button_Finish_Click(sender As Object, e As EventArgs) Handles Button_Finish.Click

    Call VariableAssign() ' that is where we assigning data to NewRecord.xxx="blah blah" etc

    Dim accountname As String = "projects"
    Dim accountkey As String = My.Settings.StorageKey
    Dim creds As StorageCredentials = New StorageCredentials(accountname, accountkey)
    Dim account As CloudStorageAccount = New CloudStorageAccount(creds, useHttps:=True)
    Dim client As CloudTableClient = account.CreateCloudTableClient()
    Dim table As CloudTable = client.GetTableReference("tdb")

    table.CreateIfNotExists()

    NewRecord.Data = _date
    NewRecord.PartitionKey = ComboBox1.SelectedItem 
    NewRecord.RowKey = NewRecord.Data

    ' Magically we write data to the cloud in Minesota
    Dim insertoperation As TableOperation
    insertoperation = TableOperation.InsertOrReplace(NewRecord)
    table.Execute(insertoperation)

    Call TimeCounter()
    exSubUpload = False
End Sub


' **here is where I do have a problem casting**.... **I think I`m missing something in the Class declaration** 

 ' Retrieve from cloud
Private Sub RetrieveFromCloud()
    'Try

    Dim accountname As String = "projects"
    Dim accountkey As String = My.Settings.StorageKey
    Dim creds As StorageCredentials = New StorageCredentials(accountname, accountkey)
    Dim account As CloudStorageAccount = New CloudStorageAccount(creds, useHttps:=True)
    Dim client As CloudTableClient = account.CreateCloudTableClient()
    Dim table As CloudTable = client.GetTableReference("tdb")

    Dim retrieveOperation As TableOperation
    Dim retrievedResult As TableResult

    retrieveOperation = TableOperation.Retrieve(ComboBox1.SelectedItem, _date)
    ' it does retrieve all data and keep it in retrievedResult 

    retrievedResult = table.Execute(retrieveOperation)

    **' that is I`m having problems - probably lack of knowledge/understanding - of how to cast all the data back to the class.**
    CloudNewRecord = retrievedResult.Result
    Debug.Print(CloudNewRecord.Project1)


End Sub

我只是不明白，为什么我可以将NewRecord写入表中，但是我无法从表中读取它到同一个CloudNewRecord类？我在VB.net中找不到任何好的例子。

感谢任何帮助。

Answer 1

GOT IT !!!!

    Dim retrieveOperation As TableOperation
    Dim retrievedResult As TableResult

    retrieveOperation = TableOperation.Retrieve(Of TimeRecord)(ComboBox1.SelectedItem, _date)
    retrievedResult = table.Execute(retrieveOperation)

    Debug.Print(DirectCast(retrievedResult.Result, TimeRecord).Project1)

Azure表检索/转换数据问题

1 个答案: