SQL 图片到 Crystal 报告

Question

我想从 SQL Server 2008 Express 中提取图像数据并直接在 Crystal 报告中显示。我正在使用 Visual Studio 2012 以及 Crystal Reports for Visual Studio（也是 SAP Crystal Reports 2013 的完整版本）。

我曾尝试使用 Google/SO 搜索中的样本，但我似乎至少遗漏了一个关键要素。在我的项目中，我有一个包含 System.Byte() 字段的数据集、一个 Crystal 报告和一个查看器。

这是查询数据库、读取内存流并将图像数据放入数据集中的代码片段。

 Dim ds As New DataSet1
   Dim row As DataRow

   Dim objConn As New SqlConnection(DatabaseConnection.CTLDataConnectionString)
   Dim objCommand As SqlCommand = objConn.CreateCommand
   objCommand.CommandText = "SELECT Content FROM Report WHERE HandlingUnitID = " & HandlingUID
   Dim dr As SqlDataReader = Nothing
   If objConn.State = ConnectionState.Closed Then objConn.Open()

   dr = objCommand.ExecuteReader

   If dr.HasRows Then
       dr.Read()
       Dim b() As Byte = DirectCast(dr("Content"), Byte())
       Using ms As New MemoryStream(b)
         ds.DataTable1.Rows.Add(b)
       End Using

   End If

   Dim rpt As New ShipLabel
   rpt.SetDataSource(ds.Tables("DataTable1"))

   Dim frm As New CRviewer
   frm.CRvwr.ReportSource = rpt
   frm.ShowDialog()

这将打开 Crystal 查看器，但它是一个空白报告。我想知道我获取数据的顺序是否正确，以及我是否将其正确存储在数据集中。

Answer 1

经过更多 reading/researching 我得到了以下代码片段，它们似乎具有正确的顺序，并且正确地将数据存储在数据集中。此片段来自 cellclick 事件。

 Dim ds As New DataSet1
   Dim row As DataRow

   Dim img As Bitmap

   Dim objConn As New SqlConnection(DatabaseConnection.CTLDataConnectionString)
   Dim objCommand As SqlCommand = objConn.CreateCommand
   objCommand.CommandText = "SELECT Content FROM Report WHERE HandlingUnitID = " & HandlingUID
   Dim dr As SqlDataReader = Nothing
   If objConn.State = ConnectionState.Closed Then objConn.Open()

   dr = objCommand.ExecuteReader

   If dr.HasRows Then
       dr.Read()
       Dim b() As Byte = dr("Content")

    Using ms As New MemoryStream(b)
        img = Image.FromStream(ms)
        b = ConvertImageToByte(img)
        ds.DataTable1.Rows.Add(b)
    End Using

   End If
   objConn.Close()

   Dim rpt As New ShipLabel
   rpt.SetDataSource(ds.Tables("DataTable1"))
   rpt.SetParameterValue("JobNumber", OrderNumber.ToString)

   Dim frm As New CRviewer
   frm.CRvwr.ReportSource = rpt
   frm.ShowDialog()

还有这个函数：

Public Shared Function ConvertImageToByte(ByVal Value As Image) As Byte()
If Value IsNot Nothing Then
    Dim fs As MemoryStream = New MemoryStream()
    CType(Value, Bitmap).Save(fs, ImageFormat.Jpeg)
    Dim retval As Byte() = fs.ToArray()
    fs.Dispose()
    Return retval
End If

Return Nothing

结束函数

SQL 图片到 Crystal 报告

SQL Image to Crystal Report

sql-server

crystal-reports

visual-studio-2012