GridView控件選擇行

自己寫模板實現選擇行並讀取相應數據，試了很多，但是都出現一個問題，兩行數據，打開的鏈接新窗口爲同一個數據。
用selectedIndexchanged簡單也不出錯

OnSelectedIndexChanged="_SelectedIndexChanged" 

<asp:CommandField runat="server" ShowSelectButton="true" ButtonType="Link" HeaderText="查看" SelectText="詳細信息" />

GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
int index = GridView1.SelectedIndex;
string ID = GridView1.SelectedDataKey.Values["UserId"].ToString();
lblRegionCaption.Text = ID;
GridViewRow row = GridView1.SelectedRow;
string url="";
...
}