Searching in Datagridview using textbox VB.net

问题

Good day I am a beginner at vb.net programming and I'm having a problem about searching or filtering the datagridview using textbox. I have a one textbox for searching and a two button for retrieving values which is the student and vehicle. When the student button clicked the data for student is displayed and same for vehicle but when I move the "Dim dtaset As New DataTable" outside the events of students,vehicle and searchtxt the search is successfully filtering the data of the datavalues also theres a problem too after moving, when click the button it adds the data for that button in datagridview but when the other button is click after the first button the data not replaced the previous one, it will just add the columns that will extend the datagrid columns. Here is my code Thank you in advance

Private Sub searchtxt_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles searchtxt.TextChanged
    con.ConnectionString = "server=localhost;userid=root;password=1234;database=dat"


    Dim dtaset As New DataTable

    Dim DV As New DataView(dtaset)
    DV.RowFilter = String.Format("FirstName Like '%{0}%'", searchtxt.Text)
    DataGridView1.DataSource = DV
End Sub

Public Sub studattenprint()
    con.ConnectionString = "server=localhost;userid=root;password=1234;database=dat"

    Dim adpter As New MySqlDataAdapter
    Dim dtaset As New DataTable
    Dim bsource As New BindingSource


    Try
        con.Open()
        Dim query As String
        query = "select idno as 'Student_ID',lastxt as 'LastName',firstxt as 'FirstName',middletxt as 'MiddleName',log as 'Status',timein as 'Timein',crse as 'Course',dates as 'Date' from dat.studdailyhistory"
        cmd = New MySqlCommand(query, con)

        adpter.SelectCommand = cmd
        adpter.Fill(dtaset)
        If dtaset.Rows.Count >= 0 Then
            numlog.Text = dtaset.Rows.Count.ToString()
        End If
        bsource.DataSource = dtaset
        DataGridView1.DataSource = bsource

        ''DataGridView Design
        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
        DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.DisplayedCells
        DataGridView1.Sort(DataGridView1.Columns(7), System.ComponentModel.ListSortDirection.Descending)

        adpter.Update(dtaset)
        con.Close()

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

Public Sub vehicattenprint()
    con = New MySqlConnection
    con.ConnectionString = "server=localhost;userid=root;password=1234;database=dat"
    Dim SDA As New MySqlDataAdapter
    Dim dtaset As New DataTable
    Dim bSource As New BindingSource


    Try

        con.Open()
        Dim query As String

        query = "select tag_no as 'Tag_No.',platenum as 'Plate no.',ownername as 'Owner_name',log as 'Status',timelog as 'Time_log',dates as 'Date' from dat.vehicdailyhistory"
        cmd = New MySqlCommand(query, con)
        SDA.SelectCommand = cmd
        SDA.Fill(dtaset)
        bSource.DataSource = dtaset
        DataGridView1.DataSource = bSource

        If dtaset.Rows.Count > 0 Then
            numlog.Text = dtaset.Rows.Count.ToString()
        End If

        SDA.Update(dtaset)
        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
        DataGridView1.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.DisplayedCells
        DataGridView1.Sort(DataGridView1.Columns(5), System.ComponentModel.ListSortDirection.Descending)

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

Private Sub vehicatten_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles vehicatten.Click
    vehicattenprint()
End Sub

Private Sub studatten_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles studatten.Click
    studattenprint()
End Sub

回答1:

After binding your dataset to the datagrid, you can try the following code snippet:

Dim dv As DataView

dv = New DataView(yourDataset.Tables(0), "YourDataColumnName= '" & Me.txtSearchBox.Text & "' ", "YourDataColumnName", DataViewRowState.CurrentRows)
Me.YourDataGridView.DataSource = dv

来源：https://stackoverflow.com/questions/48257565/searching-in-datagridview-using-textbox-vb-net