'保存图片,将文件读到流中,对于怎么将pic的值写到库中略
Dim myfilestream As New System.IO.FileStream(OpenFile.FileName, IO.FileMode.Open)
Dim pic() As Byte
Dim pic as (myfilestream.Length - 1)
myfilestream.Read(pic, 0, myfilestream.Length)
myfilestream.Close()
return strWriter.ToString()
End Function
End Class
Sub btnCreate_Click(Src As Object, E As EventArgs)
If Convert.ToDouble( txtFileSize.Text ) > 10000 Then
lblOutput.Text = "可以指定的数目的上限为 10000"
Else
If Convert.ToDouble( txtFileSize.Text ) < 1
lblOutput.Text = "可以指定的数目的下限为 1"
Else
lblOutput.Text = ReadWrite.Go( Double.Parse(txtFileSize.Text) )
End If
End If
End Sub
添加一个SqlDataAdapter1,用向导设置联接数据库为Northwnd,SQL语句为SELECT [Category ID], [Category Name], Description, Picture FROM Categories.生成一个数据集为dataset1. 然后添加两个按钮分别表示写图片到数据库和读数据库,还有一个Image控件用于显示图片.
添加以下代码
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
SqlDataAdapter1.Fill(DataSet11)
End Sub
'从数据库读取图片暂时存储为monkey.bmp,然后加载到image控件里面.
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LoadPicFromDb.Click
Try
Dim data As Byte() = DataSet11.Tables(0).Rows(7).Item(3)
Dim myfilestream As New System.IO.FileStream(Application.StartupPath & "\monkey.bmp", IO.FileMode.Create)
myfilestream.Write(data, 0, data.Length)
myfilestream.Close()
PictureBox1.Image = New Bitmap(Application.StartupPath & "\monkey.bmp")
Catch
End Try
End Sub
'把C:\6.bmp写入库中,你可以改为自己的图片.
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles InsertPicToDb.Click
Dim myfilestream As New System.IO.FileStream("c:\6.bmp", IO.FileMode.Open)
Dim data() As Byte
ReDim data(myfilestream.Length - 1)
myfilestream.Read(data, 0, myfilestream.Length)
myfilestream.Close()
DataSet11.Tables(0).Rows(7).Item(3) = data
SqlDataAdapter1.Update(DataSet11.GetChanges())
End Sub