vb.net datagridview数据修改同步到数据库

Textbox1输入查询命令（select语句后查询结果在datagridview中显示，在datagridview中修改数据按保存按钮数据更新到数据库）查询没有错误，但修改数据后保存出现错误，错误行在下面代码红色标出了，错误提示未将对象引用设置到对象的实例，我查询的表设置了主键Imports System.Data.SqlClientPublic Class Form1 Dim con As New SqlConnection Dim Com As SqlCommand Dim da As SqlDataAdapter Dim ds As DataSet ✀查询按钮代码 Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click con = New SqlConnection("data source=mypc;initial catalog=xiaoshouxt;" & "integrated security=false;user=sa;password=8348538620") con.Open() Com = New SqlCommand(TextBox1.Text, con) Dim da As SqlDataAdapter Dim ds As DataSet da = New SqlDataAdapter(com) ds = New DataSet da.Fill(ds, "ch") DataGridView1.DataSource = ds.Tables("ch") End Sub✀修改datagridview1中数据保存按钮 Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click con = New SqlConnection("data source=mypc;initial catalog=xiaoshouxt;" & "integrated security=false;user=sa;password=8348538620") con.Open() ✀保存表身修改后的数据 Dim A As New SqlCommandBuilder(da) da.Update(ds, "ch")con.close() End SubEnd Class更多 0

2026年09月27日 00:45

有1个网友回答

网友（1）：

变量的作用域的概念错误：
改用下面代码：

Imports System.Data.SqlClient
Public Class Form1

Dim con As New SqlConnection
Dim Com As SqlCommand
Dim da As SqlDataAdapter
Dim ds As DataSet

'查询按钮代码
Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
con = New SqlConnection("data source=mypc;initial catalog=xiaoshouxt;" & "integrated security=false;user=sa;password=8348538620")
con.Open()
Com = New SqlCommand(TextBox1.Text, con)
'Dim da As SqlDataAdapter '这行不要
'Dim ds As DataSet '这行不要

da = New SqlDataAdapter(com)
ds = New DataSet
da.Fill(ds, "ch")
DataGridView1.DataSource = ds.Tables("ch")
End Sub

'修改datagridview1中数据保存按钮
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
'下面两行也不要
'con = New SqlConnection("data source=mypc;initial catalog=xiaoshouxt;" & "integrated security=false;user=sa;password=8348538620")
'con.Open()

'保存表身修改后的数据
Dim A As New SqlCommandBuilder(da)
da.Update(ds, "ch")
con.close()
End Sub
End Class