将 PNG 或 JPG 插入 MySQL 会损坏图像

Question

我在将一些 JPG 或 PNG 图像插入 MySQL 时遇到问题。其中一些图像已损坏。

损坏的 JPG 截图：

损坏的 PNG 的屏幕截图：

我的代码有什么问题？

代码：

Private Sub Button3_Click_1(sender As Object, e As EventArgs) Handles Button3.Click
    Dim cmd As New MySqlCommand
    Dim SQL As String
    Dim FileSize As UInt32
    Dim rawData() As Byte = IO.File.ReadAllBytes(ListBox1.SelectedItem)
    Dim fs As FileStream
    Try
        fs = New FileStream(ListBox1.SelectedItem.ToString, FileMode.Open, FileAccess.Read)
        FileSize = fs.Length
        rawData = New Byte(FileSize) {}
        fs.Read(rawData, 0, FileSize)
        'fs.Close()
        MysqlConn.Open()
        SQL = "INSERT INTO xcollectibles.foto (foto) VALUES(@foto)"
        cmd.Connection = MysqlConn
        cmd.CommandText = SQL
        cmd.Parameters.AddWithValue("@foto", rawData)
        cmd.ExecuteNonQuery()
        fs.Close()
        MessageBox.Show("File Inserted into database successfully!",
        "Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)
        MysqlConn.Close()
    Catch ex As Exception
        MessageBox.Show("There was an error: " & ex.Message, "Error",
                MessageBoxButtons.OK, MessageBoxIcon.Error)
    End Try
End Sub

我也试过了：

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

    MysqlConn.Open()
    Me.Cursor = Cursors.WaitCursor
    For i = 0 To Me.ListBox1.Items.Count - 1
        ProgressBar1.Maximum = Me.ListBox1.Items.Count - 1
        Me.ListBox1.SetSelected(i, True)
        Dim cmd As New MySqlCommand
        Dim SQL As String
        Dim filesize As UInt32
        Dim mstream As New System.IO.MemoryStream()
        If TextBox1.Text = ".jpg" Then
            PictureBox1.Image.Save(mstream, Imaging.ImageFormat.Jpeg)

        ElseIf TextBox1.Text = ".png" Then
            PictureBox1.Image.Save(mstream, Imaging.ImageFormat.Png)

        ElseIf TextBox1.Text = ".bmp" Then
            PictureBox1.Image.Save(mstream, Imaging.ImageFormat.Png)

        End If


        'Dim bmp As New Bitmap(Width, Height)
        'Dim g As Graphics = Graphics.FromImage(bmp)
        'g.Clear(Color.Transparent)
        'bmp.Save(mstream, System.Drawing.Imaging.ImageFormat.Png)


        'End If
        ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        Dim arrImage() As Byte = mstream.GetBuffer()
        filesize = mstream.Length
        mstream.Close()
        SQL = "INSERT INTO xcollectibles.foto (id_product,foto) VALUES ((Select id from xcollectibles.product where product.name='" & ComboBox1.Text & "'), @foto) "
        ProgressBar1.Value = i
        cmd.Connection = MysqlConn
        cmd.CommandText = SQL
        cmd.Parameters.AddWithValue("@foto", arrImage)
        cmd.ExecuteNonQuery()
    Next
    MessageBox.Show("File Inserted into database successfully!", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)
    MysqlConn.Dispose()
    ProgressBar1.Value = 0
    Me.Cursor = Cursors.Default
End Sub

---

我现在尝试一些不同的东西...... 将文件保存在电脑的某个路径中，并将路径保存在mysql中

我试试这个来添加文件

System.IO.Directory.CreateDirectory("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images" & "\" & ComboBox1.Text)
        Dim SaveFile As New System.IO.StreamWriter("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images" & "\" & ComboBox1.Text & "\" & TextBox3.Text)

        If TextBox1.Text = ".jpg" Then
            PictureBox1.Image.Save("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images\mypic.jpg", System.Drawing.Imaging.ImageFormat.Jpeg)
        ElseIf TextBox1.Text = ".bmp" Then
            PictureBox1.Image.Save("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images\mypic.bmp", System.Drawing.Imaging.ImageFormat.Bmp)
        ElseIf TextBox1.Text = ".png" Then
            PictureBox1.Image.Save("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images\mypic.png", System.Drawing.Imaging.ImageFormat.Png)
        End If

但我想用文件夹保存文件

System.IO.Directory.CreateDirectory("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images" & "\" & ComboBox1.Text)

并以TextBox3.Text的名称保存文件

Dim SaveFile As New System.IO.StreamWriter("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images" & "\" & ComboBox1.Text & "\" & TextBox3.Text)

因为在例子中

PictureBox1.Image.Save("C:\Users\Jamyz\Source\Repos\xCollectibles\xCollectibles\xCollectibles\Images\mypic.jpg", System.Drawing.Imaging.ImageFormat.Jpeg)

文件被覆盖........

非常感谢......

Answer 1

您必须先将图像转换为字节数组，然后才能将其存储到数据库中。我使用Oracle，但我想Sql Server 是一样的。我从上传中捕获照片，将图像缩放为缩略图，然后将其转换为字节数组以存储在数据库中。见以下代码：

    If Not file1.PostedFile Is Nothing And file1.PostedFile.ContentLength > 0 Then
        Session("ThePhoto") = ""
        Dim TheStream As Stream = file1.PostedFile.InputStream
        Dim origimage As System.Drawing.Image
        origimage = System.Drawing.Image.FromStream(TheStream)

        Dim ms2 As New System.IO.MemoryStream
        origimage = ScaleImage(origimage, 320, 200) ' Thumbnail
        origimage.Save(ms2, Imaging.ImageFormat.Jpeg)
        Dim MyPhoto() As Byte = ms2.GetBuffer ' The scaled image is now stored in memory as a byte array
        Session("ThePhoto") = MyPhoto ' put it into the session to retreive later
        ms2.Dispose()
        origimage.Dispose()
    End If

我将图像存储在会话对象中，因为还有其他事情正在进行，并且在用户单击保存按钮之前，我还无法将图像保存到数据库中。将字节数组传递给存储过程以保存到数据库非常简单。

Answer 2

感谢我使用它的帮助。问题解决了

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

    Me.Cursor = Cursors.WaitCursor
    For i = 0 To Me.ListBox1.Items.Count - 1
        ProgressBar1.Maximum = Me.ListBox1.Items.Count - 1
        Me.ListBox1.SetSelected(i, True)
        Dim cmd As New MySqlCommand
        Dim SQL As String
        'Dim FileSize As UInt32
        Dim rawData() As Byte = IO.File.ReadAllBytes(ListBox1.SelectedItem)


        Dim mstream As New System.IO.MemoryStream()
        Dim arrImage() As Byte = mstream.GetBuffer()
        mstream.Close()

        'Save Image in Folder
        Dim strBasePath As String
        Dim strFileName As String
        strFileName = TextBox3.Text
        strBasePath = Application.StartupPath & "\Images" & ComboBox1.Text & "\"
        ' >> Check if Folder Exists 
        If Directory.Exists(strBasePath) = False Then
                Call Directory.CreateDirectory(strBasePath)
            End If
        ' >> Save Picture 
        If TextBox1.Text = ".jpg" Then
            Call PictureBox1.Image.Save(strBasePath & "\" & strFileName, System.Drawing.Imaging.ImageFormat.Jpeg)
        ElseIf TextBox1.Text = ".png" Then
            Call PictureBox1.Image.Save(strBasePath & "\" & strFileName, System.Drawing.Imaging.ImageFormat.Png)
        ElseIf TextBox1.Text = ".bmp" Then
            Call PictureBox1.Image.Save(strBasePath & "\" & strFileName, System.Drawing.Imaging.ImageFormat.Bmp)
        End If
        'Save Image in Folder

        MysqlConn.Close()
        MysqlConn.Open()
        SQL = "INSERT INTO xcollectibles.foto (id_product,name,path) VALUES ((Select id from xcollectibles.product where product.name='" & ComboBox1.Text & "'), @name, @path) "
        ProgressBar1.Value = i
        cmd.Connection = MysqlConn
        cmd.CommandText = SQL
        cmd.Parameters.AddWithValue("@name", TextBox3.Text)
        cmd.Parameters.AddWithValue("@path", strBasePath)
        cmd.ExecuteNonQuery()
    Next
    MessageBox.Show("File Inserted into database successfully!", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk)
    MysqlConn.Dispose()
    ProgressBar1.Value = 0
    Me.Cursor = Cursors.Default
End Sub