从数据库检索照片到PictureBox
问题描述:
我有一个VB.NET项目与2 WinForms。现在在Form 1,我添加了一个PictureBox,一个Button,一个OpenFileDialog。我已经编码按钮来将图片从PictureBox添加到SQL数据库。现在我在Form 2有另一个picturebox。从数据库检索照片到PictureBox
所以我的问题是,如何从sql数据库检索图像并将其显示在图片框中?
连接字符串如下:
Dim con As New SqlConnection
con.ConnectionString = "Data source=" & My.Settings.sqlserver & "," & My.Settings.sqlport &
";Network Library=DBMSSOCN;initial catalog=" & My.Settings.dbname &
";User id=" & My.Settings.Username &
";Password=" & My.Settings.Password & ";"
Dim cmd As New SqlCommand("select * from userandadmins where Username = @username and Password = @password", con)
con.Open()
答
我使用Oracle存储照片。您需要使用与存储照片的字段类型相同的out参数来检索照片。我假设这是一个BLOB。在将照片存储在数据库中之前,您必须将其转换为字节数组。由于这不是问题,所以我会发布我用来从Oracle数据库检索照片的代码,转换为Sql Server代码应该是一件简单的事情。
我打开到数据库的连接并将其传递给检索函数。我返回包含一行数据,照片和其他识别信息的数据集。然后我将BLOB分配给一个变量,从那里做你需要的。我用它做的是把它分配给一个图像控件,它调用另一个aspx页面来检索照片(imageURL)。检索它的代码位于被调用的“Image.aspx”中,然后将照片返回给图像控件。该HTML是在GetPhoto函数下面。这样我就不需要将照片存储在硬盘上的任何地方并找回它。
Dim MyConnection As New OracleConnection
Dim MyDataSet As New DataSet
Dim MyPhoto() As Byte = {}
MyConnection = OpenConnection(Session("USERNAME"), Session("PASSWORD"))
MyDataSet = GetPhoto(MyConnection, pPhotoID)
myPhoto = MyDataSet.Tables("Data").Rows(0)("Photo")
Public Function GetPhoto(ByVal TheConnection As OracleConnection, ByVal pPhotoID As String) As DataSet
Dim myCommand As New OracleCommand
Dim DS As New DataSet
Try
With myCommand
.Connection = TheConnection
.CommandText = "Darlington.PlayerSignUps.GetPhoto"
.CommandType = CommandType.StoredProcedure
.Parameters.Clear()
.Parameters.Add(New OracleParameter("pPhotoID", OracleDbType.Varchar2, pPlayerID.Length)).Value = pPhotoID
.Parameters.Add(New OracleParameter("pDataOut", OracleDbType.RefCursor))
.Parameters(0).Direction = ParameterDirection.Input
.Parameters(1).Direction = ParameterDirection.Output
Dim DA As New OracleDataAdapter(myCommand)
DA.Fill(DS, "DATA")
GetPhoto = DS
End With
Catch exc As Exception
Throw New Exception("Error occured while retreiving photo from database, the error is: " & exc.Message)
End Try
myCommand = Nothing
End Function
<tr>
<td style="width: 372px; text-align: center">
<asp:Image ID="Image_Photo" runat="server" ImageUrl="Image.aspx" />
</td>
</tr>
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