從SQL數據庫將圖片檢索到Picturebox時，VB.NET中的“參數無效”錯誤

Question

Dim con As New SqlConnection
Dim cmd As New SqlCommand
Dim str As String
Dim dr As SqlDataReader

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    str = "select * from llr where llrno='" & TextBox1.Text & "'"
    cmd = New SqlCommand(str, con)
    con.Open()
    dr = cmd.ExecuteReader()
    If dr.HasRows Then
        dr.Read()
        Dim img As Byte() = DirectCast(dr("img"), Byte())
        Dim ms As New MemoryStream(img)
        PictureBox1.Image = Image.FromStream(ms)
    End If
    dr.Close()
    cmd.Dispose()
    con.Close()
End Sub

Answer 1

我認為問題可能出在前一行，請嘗試更改為：

Dim img As Byte() = dr("img") 

看看是否出現相同的錯誤。