显示先前在Picturebox中扫描或检索的图像 [英] Displaying a Image previous scanned or retrieved in Picturebox

问题描述

我只希望对我的RFID考勤系统项目有所帮助.应该扫描RFID标签以从数据库mysql检索信息和图像.第一位学生将扫描他的RFID标签以在picturebox1中显示他的照片，而另一位学生扫描时，picturebox1将被更新为新的学生照片和数据，并且先前的照片在所显示的picturebox2上.这里的问题是如何显示以前的照片学生的形象.仅图像，不包含数据.

I just want some help for my project which is RFID attendance system. The RFID tag should be scan to retrieve the information and Image from the database mysql. The first student will scan his RFID tag to display his picture in picturebox1 and when another student scan the picturebox1 will be updated to a new student picture and data and the previous one is on the picturebox2 displayed The issue here is how can I display the previous Image of the student. Just only the Image ,the data is not included.

我有2个图片框

Picturebox1适用于扫描的新学生 Picturebox2适用于上一个或在新版本之前扫描的学生.

Picturebox1 is for new student scanned Picturebox2 is for the previous one or the student who scan before the new.

谢谢..任何建议和评论将完全赞赏

Thank you guys ..Any suggestions and comment will totally appreciated

这是我的代码

Private Sub studtag_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles studtag.TextChanged
    If studtag.TextLength = 8 Then


        con = New MySqlConnection
        con.ConnectionString = "server=localhost;userid=root;password=1234;database=dat"
        Dim query As String

        query = "select * from dat.students"
        cmd = New MySqlCommand(query, con)



        Dim table As New DataTable

        Try
            con.Open()
            'Gets or sets an SQL statement or stored procedure used to select records in the database.
            With cmd
                .Connection = con
                .CommandText = "SELECT * from students where `studtags`='" & studtag.Text & "';"
            End With
            da.SelectCommand = cmd
            da.Fill(table)
            'it gets the data from specific column and fill it into textbox
            studtag.Text = table.Rows(0).Item(0)
            idno.Text = table.Rows(0).Item(1)
            lastxt.Text = table.Rows(0).Item(2)
            firstxt.Text = table.Rows(0).Item(3)
            middletxt.Text = table.Rows(0).Item(4)
            dob.Text = table.Rows(0).Item(6)

            crsetxt.Text = table.Rows(0).Item(10)

            tagtxt.Text = studtag.Text
            timein.Text = times.Text

            dr = cmd.ExecuteReader()
            dr.Read()

            If dob.Text = datenow.Text Then
                greet.Text = "Happy Birthday To You"

            End If



            Dim img() As Byte = CType(dr("studpic"), Byte())


            Using ms As New IO.MemoryStream(img)
                PictureBox1.Image = Image.FromStream(ms)

            End Using
            insert()
            loadtable()

        Catch ex As Exception
            Notenrolled.Show()
        Finally

            con.Dispose()
            con.Close()
        End Try

    End If

End Sub

Public Sub loadtable()

    con = New MySqlConnection
    con.ConnectionString = "server=localhost;userid=root;password=1234;database=dat"
    Dim SDA As New MySqlDataAdapter
    Dim dbDataset As New DataTable
    Dim bSource As New BindingSource


    Try

        con.Open()
        Dim query3 As String

        query3 = "select studtags,idno,lastxt,firstxt,middletxt,dob,log,timein,crse from dat.studlogs"
        cmd = New MySqlCommand(query3, con)
        SDA.SelectCommand = cmd
        SDA.Fill(dbDataset)
        bSource.DataSource = dbDataset
        DataGridView1.DataSource = bSource
        SDA.Update(dbDataset)
        DataGridView1.Sort(DataGridView1.Columns(8), System.ComponentModel.ListSortDirection.Ascending)
        If dbDataset.Rows.Count > 0 Then
            logins.Text = table2.Rows.Count.ToString()
        End If


        con.Close()
    Catch ex As Exception
        MessageBox.Show(ex.Message)
    Finally
        con.Dispose()
    End Try
End Sub

 Private Sub Students_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


    loadtable()
    ''Date Now 
    Timer2.Start()


    Try
        DataGridView1.AllowUserToAddRows = False ' Disabled or hide (*) Symbol...

        DataGridView1.RowHeadersVisible = False 'To hide Left indicator..
        DataGridView1.DefaultCellStyle.SelectionBackColor = Color.SteelBlue  'Selection backcolor....
        DataGridView1.AlternatingRowsDefaultCellStyle.BackColor = Color.LightGoldenrodYellow 'Alternating Backcolor.
        DataGridView1.AllowUserToResizeRows = False 'Disabled  row resize...
        DataGridView1.ReadOnly = True
        DataGridView1.MultiSelect = False
        DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect
        DataGridView1.ShowRowErrors = False
        DataGridView1.ShowCellErrors = False


        table2.Columns.Add("Student Tag", Type.GetType("System.String"))
        table2.Columns.Add("Student ID", Type.GetType("System.Int32"))
        table2.Columns.Add("Last Name", Type.GetType("System.String"))
        table2.Columns.Add("First Name", Type.GetType("System.String"))
        table2.Columns.Add("Middle Name", Type.GetType("System.String"))

        table2.Columns.Add("Status", Type.GetType("System.String"))
        table2.Columns.Add("Birthday", Type.GetType("System.String"))
        table2.Columns.Add("Time in", Type.GetType("System.String"))
        table2.Columns.Add("Course/Sec", Type.GetType("System.String"))


    Catch ex As Exception

    End Try

推荐答案

很简单，您可以使用按钮显示上一张图片:

It's quiet easy,You can use a button to display the previous image :

  If datagridview1.CurrentRow.Index < datagridview1.Rows.Count Then
  datagridview1.Rows(datagridview1.SelectedRows(0).Index - 1).Selected 
             = True
 Dim pic As Byte()
 pic = datagridview1.CurrentRow.Cells(1).Value
 Dim ms As New MemoryStream(pic)
 pbox1.BackgroundImage = Image.FromStream(ms) 

这篇关于显示先前在Picturebox中扫描或检索的图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！