在DataGrid中搜索（过滤器）VB.Net

Question

我有这个程序，让用户/管理员通过DataGrid搜索某个学生。要搜索学生，他们需要通过ComboBox（分别具有年份级别，ID号码，姓氏和程序名称）进行选择，并在文本框中键入相应的搜索关键字。 DataGrid将根据ComboBox中的选定项和关键字进行过滤，并且只有少数记录会显示在数据网格中。

下面是搜索代码：

If cmbSearch.SelectedItem = "Year Level" Then 
      Dim records = From STUDENT In StudentDB2DataSet.STUDENT Where STUDENT.YEARLEVEL Like txtKeyword.Text & "*" Select STUDENT 
      STUDENTBindingSource.DataSource = records.AsDataView 
     ElseIf cmbSearch.SelectedItem = "ID Number" Then 
      Dim records = From STUDENT In StudentDB2DataSet.STUDENT Where STUDENT.IDNUMBER Like txtKeyword.Text & "*" Select STUDENT 
      STUDENTBindingSource.DataSource = records.AsDataView 
     ElseIf cmbSearch.SelectedItem = "Last Name" Then 
      Dim records = From STUDENT In StudentDB2DataSet.STUDENT Where STUDENT.LNAME Like txtKeyword.Text & "*" Select STUDENT 
      STUDENTBindingSource.DataSource = records.AsDataView 
     ElseIf cmbSearch.SelectedItem = "Program Code" Then 
      Dim records = From STUDENT In StudentDB2DataSet.STUDENT Where STUDENT.PROGCODE Like txtKeyword.Text & "*" Select STUDENT 
      STUDENTBindingSource.DataSource = records.AsDataView 
     End If 

虽然声明的BindingSources等等是正确的，将DataGrid并根据组合框，并在关键字文本值设置的条件不过滤框。在添加有关以其他形式查看这些数据的其他代码块之前，它曾经工作过。当我删除我添加的代码块时，它仍然不起作用。有谁知道什么可能是错的？我想我需要添加一些东西，但我实际上并不那么流利地使用VB.Net。提前致谢！

编辑：这是我对frmSearch_Load事件的代码。这将使用MS Access数据库文件中的精确值和记录刷新DataGrid。

Dim myConString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\StudentDirectory2\StudentDB2.accdb" 
    con.ConnectionString = myConString 
    con.Open() 
    da = New OleDbDataAdapter("select * from STUDENT", con) 
    ds = New DataSet 
    da.Fill(ds, "STUDENT") 
    DataGridView1.DataSource = ds.Tables("STUDENT") 
    DataGridView1.DataSource = dt 
    dtTableGrd = dt 

    con.Close() 

    DataGridView1.DataSource = ds.Tables("STUDENT") 
    con.Close() 

这里是填充的DataGridView代码：

Imports System.Data.OleDb 
Imports System.Data 
Imports System.Collections 
Imports System.IO 

Public Class frmSearch 

    Dim con1 As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\StudentDirectory2\StudentDB2.accdb") 
    Dim con As New OleDbConnection 
    Dim ds As New DataSet 
    Dim ds2 As New DataSet 
    Dim dt As New DataTable 
    Dim da As New OleDbDataAdapter 
    Dim da2 As New OleDbDataAdapter 

    Dim provider As String 
    Dim dataFile As String 
    Dim connString As String 
    Public myConnection As OleDbConnection = New OleDbConnection 
    Public dr As OleDbDataReader 
    Public dr2 As OleDbDataReader 

Private Sub frmSearch_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
     'TODO: This line of code loads data into the 'StudentDB2DataSet.STUDENT' table. You can move, or remove it, as needed. 
     Me.STUDENTTableAdapter.Fill(Me.StudentDB2DataSet.STUDENT) 
     'TODO: This line of code loads data into the 'StudentDB2DataSet.STUDENT' table. You can move, or remove it, as needed. 
     Me.STUDENTTableAdapter.Fill(Me.StudentDB2DataSet.STUDENT) 
     'TODO: This line of code loads data into the 'StudentDB2DataSet.STUDENT' table. You can move, or remove it, as needed. 
     Me.STUDENTTableAdapter.Fill(Me.StudentDB2DataSet.STUDENT) 
     'TODO: This line of code loads data into the 'StudentDB2DataSet.STUDENT' table. You can move, or remove it, as needed. 
     Me.STUDENTTableAdapter.Fill(Me.StudentDB2DataSet.STUDENT) 
     'TODO: This line of code loads data into the 'UserDBDataSet.tblUser' table. You can move, or remove it, as needed. 




     Dim myConString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\StudentDirectory2\StudentDB2.accdb" 
     con.ConnectionString = myConString 
     con.Open() 
     da = New OleDbDataAdapter("select * from STUDENT", con) 
     ds = New DataSet 
     da.Fill(ds, "STUDENT") 
     DataGridView1.DataSource = ds.Tables("STUDENT") 
     DataGridView1.DataSource = dt 


     con.Close() 

     DataGridView1.DataSource = ds.Tables("STUDENT") 
     con.Close() 
     'DataGridView.ColumnCount = 6 
     'DataGridView.Columns(0).Name = "IDNumber" 
     'DataGridView.Columns(1).Name = "LastName" 
     'DataGridView.Columns(2).Name = "FirstName" 
     'DataGridView.Columns(3).Name = "MiddleInitial" 
     'DataGridView.Columns(4).Name = "YearLevel" 
     'DataGridView.Columns(5).Name = "Program" 

     'STUDENTBindingSource1.Sort = "IDNUMBER" 
     'TODO: This line of code loads data into the 'StudDirDBDataSet.tblStudent' table. You can move, or remove it, as needed. 

     Me.STUDENTTableAdapter.Fill(Me.StudentDB2DataSet.STUDENT) 
     DataGridView1.Refresh() 

     Dim user As String 

     user = frmLogin.cmbUsername.SelectedItem 

     If user = "User" Then 
      btnUpdate.Enabled = False 
      btnDelete.Enabled = False 
     End If 

     'Me.STUDENTTableAdapter1.Fill(Me.StudentDB2DataSet1.STUDENT) 
     'TODO: This line of code loads data into the 'StudDirDBDataSet.tblStudent' table. You can move, or remove it, as needed. 
     ' Me.STUDENTTableAdapter1.Fill(Me.StudentDB2DataSet1.STUDENT) 
     'TODO: This line of code loads data into the 'StudDirDBDataSet.tblStudent' table. You can move, or remove it, as needed. 
     ' Me.STUDENTTableAdapter1.Fill(Me.StudentDB2DataSet1.STUDENT) 
     'TODO: This line of code loads data into the 'StudDirDBDataSet.tblStudent' table. You can move, or remove it, as needed. 
     ' Me.STUDENTTableAdapter1.Fill(Me.StudentDB2DataSet1.STUDENT) 

End Sub 

Answer 1

多一点的代码将是有益的，特别是如果u有数据绑定.. 反正这可能工作：

Private dtTable As New DataTable 
Private dtTableGrd As DataTable 

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load 
DataGridView1.DataSource = dtTable 
    dtTableGrd = dtTable 
End Sub 

Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged 
    dtTableGrd.DefaultView.RowFilter = "ID Number Like '%" & TextBox1.Text & "%'" 
End Sub