请教“未将对象引用设置到对象的实例”如何解决??
private void Page_Load(object sender, System.EventArgs e)
{
SqlConnection conn=new SqlConnection("server=localhost;uid=sa;pwd=;database=dl;");
SqlDataAdapter da=new SqlDataAdapter("select * from dl",conn);
DataSet ds=new DataSet();
da.SelectCommand.CommandText="select * from dl";
SqlCommandBuilder cmd=new SqlCommandBuilder(da);
DataRow row=ds.Tables["dl"].NewRow();
row["yhm"]="66";
row["mm"]="66";
ds.Tables["dl"].Rows.Add(row);
da.Update(ds.Tables["dl"]);
}
运行时报错
异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。
源错误:
行 27: da.SelectCommand.CommandText="select * from dl";
行 28: SqlCommandBuilder cmd=new SqlCommandBuilder(da);
行 29: DataRow row=ds.Tables["dl"].NewRow();
行 30: row["yhm"]="66";
行 31: row["mm"]="66";