尝试将内容文件复制到lonelystorage时出现NullReferenceException [英] NullReferenceException when trying to copy content file to isolatedstorage

问题描述

我正在尝试将文件复制到IsolatedStorage的资源，我正在使用以下代码。但我得到一个错误NullRefernceException。请帮助找到错误。

I am trying to copy an file to the resource to the IsolatedStorage, for which i am using the following code. But i get an error an NullRefernceException. Please help in finding the error.

Private Sub Page1_Loaded(sender As Object, e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
        Try
            Me.CopyFromContentToStorage("DataFiles/Customers.xml")
        Catch ex As Exception
            MessageBox.Show("Could not gather the Customers List", "Order Entry System", MessageBoxButton.OK)
        End Try
    End Sub

    Private Sub CopyFromContentToStorage(fileName As [String])
        Try

            Using Store As IsolatedStorageFile = IsolatedStorageFile.GetUserStoreForApplication
                Using Src As Stream = Application.GetResourceStream(New Uri("/OrderEntrySystem;component/" + fileName, UriKind.Relative)).Stream
                    Using IsoStream As New IsolatedStorageFileStream("/OrderEntrySystem;component/" + fileName, FileMode.OpenOrCreate, FileAccess.Write, Store)
                        Src.Position = 0
                        CopyStream(Src, IsoStream)
                        IsoStream.Flush()
                    End Using
                End Using
            End Using

        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

    Private Shared Sub CopyStream(input As Stream, output As IsolatedStorageFileStream)
        Dim buffer As Byte() = New Byte(32767) {}
        Dim TempPos As Long = input.Position
        Dim readCount As Integer
        Do
            readCount = input.Read(buffer, 0, buffer.Length)
            If readCount > 0 Then
                output.Write(buffer, 0, readCount)
            End If
        Loop While readCount > 0
        input.Position = TempPos
    End Sub

我认为路径存在一些问题。

I think there is some problem with the path.

我的项目名称是"OrderEntrySystem_WP"但我已将程序集名称处理为"OrderEntrySystem"

My Project Name Is "OrderEntrySystem_WP" but i have chagned the assembly name to "OrderEntrySystem"

推荐答案

您有"构建行动"作为内容。因此，您不必编写"/ OrderEntrySystem; component /"

You have "Build Action" as Content. So you don't have to write "/OrderEntrySystem;component/"

请参阅以下链接了解详细信息

Refer following link for detail

http://msdn.microsoft.com/en-us/library/windowsphone/develop /ms596994(v=vs.105).aspx

您在IsolatedStorageFileStream中的文件路径不正确。尝试以下代码

Your file path in IsolatedStorageFileStream is not correct. Try following code

 Using Src As Stream = Application.GetResourceStream(fileName, UriKind.Relative)).Stream
                    Using IsoStream As New IsolatedStorageFileStream(fileName,FileMode.OpenOrCreate, FileAccess.Write, Store)
                        Src.Position = 0
                        CopyStream(Src, IsoStream)
                        IsoStream.Flush()
                    End Using
                End Using

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