Public myda As SqlClient.SqlDataAdapter
Public dset As New DataSet
Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim sqlstr As String
sqlstr = "select * from t_user"
myda = New SqlClient.SqlDataAdapter(sqlstr, mycon)
myda.Fill(dset, "用户表")
DataGrid1.DataSource = dset.Tables("用户表")
End Sub

Private Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
myda.Update(dset.GetChanges)
dset.AcceptChanges()
End Sub
我想在datagrid1修改一条记录
代码执行button1_click事件可以正常执行
但是执行button2_clikc就有错误
不知道我这两句代码有什么问题，麻烦大家帮看一下
myda.Update(dset.GetChanges)
dset.AcceptChanges()

Public myda As SqlClient.SqlDataAdapter
Public dset As New DataSet

Dim sqlstr As String
sqlstr = "select * from t_user"
myda = New SqlClient.SqlDataAdapter(sqlstr, mycon)

Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
myda.Fill(dset, "用户表")
DataGrid1.DataSource = dset.Tables("用户表")
End Sub

Private Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
myda.Update(dset.GetChanges)
dset.AcceptChanges()
End Sub
只是改变了一段代码的顺序。你原先的程序中触发myda.Update(dset.GetChanges)时myda的构造还没有完成。Button1_Click和Button2_Click是并列的对象，Button1_Click中的动作一般不能影响Button2_Click的动作。