Vb.net 无法使用 ms.access 数据库保存图片

问题描述

好吧，如果这听起来很烦人，请原谅我，但是每当我尝试输入我的数据时，我总是收到一个错误 nullreference.. 如果我做错了，我很抱歉这是我第一次在这里发帖：

Imports System.IO
Imports System.Data.OleDb
Public Class halaman_daftar_anggota

Dim Conn As OleDbConnection
Dim da As OleDbDataAdapter
Dim ds As DataSet
Dim CMD As OleDbCommand

Dim bytimage As Byte()

Dim LokasiDB As String
Sub Koneksi()
    LokasiDB = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=perpustakaan.accdb"
    Conn = New OleDbConnection(LokasiDB)
    If Conn.State = ConnectionState.Closed Then Conn.open()
End Sub
Private Sub halaman_daftar_anggota_Load(sender As Object,e As EventArgs) Handles MyBase.Load
    Koneksi()
    da = New OleDbDataAdapter("Select * from data_anggota",Conn)
    ds = New DataSet
    ds.Clear()
    da.Fill(ds,"data_anggota")
End Sub

Private Sub Button2_Click(sender As Object,e As EventArgs) Handles Button2.Click
    Dim dialog As OpenFileDialog = New OpenFileDialog()

    dialog.Title = "browse Foto"
    dialog.Filter = "image files(*.png; *.bmp; *.jpg;*.jpeg; *.gif; |*.png; *.bmp; *.jpg;*.jpeg; *.gif;)"
    If dialog.ShowDialog() = Windows.Forms.DialogResult.OK Then
        PictureBox1.Image = Image.FromFile(dialog.FileName)
    End If

End Sub

Private Sub Button1_Click(sender As Object,e As EventArgs) Handles Button1.Click
    Try
        Dim ms As New System.IO.MemoryStream
        Dim bmpimage As New Bitmap(PictureBox1.Image)

        bmpimage.Save(ms,System.Drawing.Imaging.ImageFormat.Jpeg)
        bytimage = ms.ToArray()
    Catch ex As Exception
        MsgBox(ex.Message)
    End Try
    Call Koneksi()
    Dim simpan As String = "INSERT INTO data_buku (nomor_induk,nama_siswa,kelas_siswa,foto) values ('" & TextBox1.Text & "','" & TextBox2.Text & "','" & TextBox3.Text & "','" & TextBox4.Text & "',@image)"
    CMD.Parameters.AddWithValue("@image",bytimage) <-"Error object reference not set to an instance of an object"
    CMD = New OleDbCommand(simpan,Conn)
    CMD.ExecuteNonQuery()
    MsgBox("Berhasil")
End Sub
End Class

每当我试图在我的数据库中保存图片时，j 已经将 foto 设置为 ole 对象...对不起..

解决方法

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