简单的通过连接数据库给下拉菜单赋值(DropDownList)

最新推荐文章于 2021-05-21 02:09:57 发布

shenghui188

最新推荐文章于 2021-05-21 02:09:57 发布

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文章标签：数据库 database server object cmd class

本文介绍了一个使用ASP.NET实现的省份与城市下拉框联动的示例代码。该示例通过两个DropDownList控件展示从数据库中获取的省份和对应城市数据，当选择省份时会动态更新显示对应的城市。

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protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
SqlConnection con = new SqlConnection("server=;database=province;uid=sa;pwd=sa;");
con.Open();
SqlCommand cmd = new SqlCommand("select * from province", con);
SqlDataReader sdr = cmd.ExecuteReader();
DropDownList1.DataSource = sdr;
DropDownList1.DataTextField = "proname";
DropDownList1.DataValueField = "proid";
DropDownList1.DataBind();
con.Close();
sdr.Close();
}


}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{

SqlConnection con = new SqlConnection("server=;database=province;uid=sa;pwd=sa;");
con.Open();
SqlCommand cmd2 = new SqlCommand("select * from city where proid=" + DropDownList1.SelectedValue, con);
SqlDataReader sdr2 = cmd2.ExecuteReader();
DropDownList2.DataSource = sdr2;
DropDownList2.DataTextField = "cityname";
DropDownList2.DataValueField = "cityid";
DropDownList2.DataBind();
DropDownList2.Visible = true;
sdr2.Close();
con.Close();

}

前台:
<td class="td_page">新闻类型:</td>
<td><asp:DropDownList ID="dropNewType" runat="server"></asp:DropDownList></td>

后台:
DataTable dt = CDB.FillTable("select TypeId, TypeContent from [newsTypeTable]");
dropNewType.DataSource = dt;
dropNewType.DataTextField = "typeContent";
dropNewType.DataValueField = "TypeId";
dropNewType.DataBind();