C# 更新listView问题???

if(IsEdit==DialogResult.OK)
{
listView1.SelectedItems[0].Tag="ok";
listView1.SelectedItems[0].SubItems[1].Text="s1";
listView1.SelectedItems[0].SubItems[2].Text="s2";
listView1.SelectedItems[0].SubItems[3].Text="s3";
listView1.SelectedItems[0].SubItems[4].Text="s4";
}
listView1.Update();怎么没反应?
listView1.View==Details的.