我们经常会用到下拉框dropdownlist
下面附上使用代码
前端(工具箱直接拖进来即可)
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged"></asp:DropDownList>
后端
代码一定要写在整体程序Page_Load
下,不要写在DropDownList1_SelectedIndexChanged
(我当时就是傻了写在后者里了,嘤嘤嘤)
protected void Page_Load(object sender, EventArgs e)
{
string constr = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
SqlConnection conn = new SqlConnection(constr);
conn.Open();
string queryRecord;
queryRecord = "SELECT hosname FROM hospital_log ";
SqlCommand com;
com = new SqlCommand(queryRecord, conn);
SqlDataReader sqlreader;
sqlreader = com.ExecuteReader();
this.DropDownList1.DataSource = sqlreader;
this.DropDownList1.DataTextField = "hosname";
this.DropDownList1.DataValueField = "hosname";
this.DropDownList1.DataBind();
this.DropDownList1.Items.Insert(0, new ListItem("<--请选择-->", ""));
sqlreader.Close();
}
前面的连接数据库代码可见之前博客
拜拜
如若要2个以上dropdownlist进行互联可见两个dropdownlist互联