问题描述
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ImportsSystem.Data.SqlClientPublicClassForm1DimconAsNewSqlConnectionDimComAsSqlCommandDimdaAsSqlDataAdapterDimdsAsDataSet'查询按钮代码PrivateSubButton1_Click_1(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesButton1.Clickcon=NewSqlConnection("datasource=mypc;initialcatalog=xiaoshouxt;"&"integratedsecurity=false;user=sa;password=8348538620")con.Open()Com=NewSqlCommand(TextBox1.Text,con)DimdaAsSqlDataAdapterDimdsAsDataSetda=NewSqlDataAdapter(com)ds=NewDataSetda.Fill(ds,"ch")DataGridView1.DataSource=ds.Tables("ch")EndSub'修改datagridview1中数据保存按钮PrivateSubButton2_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesButton2.Clickcon=NewSqlConnection("datasource=mypc;initialcatalog=xiaoshouxt;"&"integratedsecurity=false;user=sa;password=8348538620")con.Open()'保存表身修改后的数据DimAAsNewSqlCommandBuilder(da)da.Update(ds,"ch")con.close()EndSubEndClass