在VB.NET中使用2个组合框填充数据网格视图

Imports System.Data.SqlClient

Public Class Form1
    Private connectionString As String = "YourConnectionString"
    Private dataTable As New DataTable()

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 初始化第一个组合框的数据源
        comboBox1.DataSource = GetComboBox1Data()
        comboBox1.DisplayMember = "CategoryName"
        comboBox1.ValueMember = "CategoryID"

        ' 初始化第二个组合框的数据源
        comboBox2.DataSource = GetComboBox2Data()
        comboBox2.DisplayMember = "ProductName"
        comboBox2.ValueMember = "ProductID"
    End Sub

    Private Sub comboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles comboBox1.SelectedIndexChanged
        ' 根据第一个组合框的选择值筛选数据
        Dim categoryId As Integer = CInt(comboBox1.SelectedValue)
        Dim filteredData = dataTable.AsEnumerable().Where(Function(row) row.Field(Of Integer)("CategoryID") = categoryId).CopyToDataTable()

        ' 更新数据网格视图的显示
        dataGridView1.DataSource = filteredData
    End Sub

    Private Sub comboBox2_SelectedIndexChanged(sender As Object, e As EventArgs) Handles comboBox2.SelectedIndexChanged
        ' 根据第二个组合框的选择值筛选数据
        Dim productId As Integer = CInt(comboBox2.SelectedValue)
        Dim filteredData = dataTable.AsEnumerable().Where(Function(row) row.Field(Of Integer)("ProductID") = productId).CopyToDataTable()

        ' 更新数据网格视图的显示
        dataGridView1.DataSource = filteredData
    End Sub

    Private Function GetComboBox1Data() As DataTable
        ' 获取第一个组合框的数据源
        Dim query As String = "SELECT DISTINCT CategoryID, CategoryName FROM Products"
        Dim adapter As New SqlDataAdapter(query, connectionString)
        adapter.Fill(dataTable)

        Return dataTable
    End Function

    Private Function GetComboBox2Data() As DataTable
        ' 获取第二个组合框的数据源
        Dim query As String = "SELECT DISTINCT ProductID, ProductName FROM Products"
        Dim adapter As New SqlDataAdapter(query, connectionString)
        adapter.Fill(dataTable)

        Return dataTable
    End Function
End Class