![](/img/trans.png)
[英]how to retrieve data from dynamically added label,drop down list in dynamically added div tag in asp.net c#
[英]fill drop down list from database dynamically in asp.net c#
我用c#在asp.net应用程序中下拉列表。 下拉列表的元素来自数据库(用户名)。 默认情况下,我的下拉列表显示我选择的名字作为名字。 即当我打开页面时,我看到该名称已被选择。 我希望选择的名称应类似于“ nworks用户”。 我尝试通过使用代码:
<asp:DropDownList ID="DropDownListSelectEmployee" runat="server" AutoPostBack="true"
OnSelectedIndexChanged="DropDownListSelectEmployee_SelectedIndexChanged"
OnTextChanged="DropDownListSelectEmployee_TextChanged" Height="30px" Width="250px">
<asp:ListItem Selected="True">nWorks Employee</asp:ListItem>
</asp:DropDownList>
但没有用。 我尝试的下一个选项是: DropDownListSelectEmployee.Selecteditem.Text="nWorks User";
再次没有用。 我正在使用代码从数据库中获取项目:
public void
DropDownListSelectEmployee_Fill()
{
if (!Page.IsPostBack)
{
DropDownListSelectEmployee.Items.Clear();
string q = "select username from nworksuser where _type='Employee';";
MySqlCommand cmd = new MySqlCommand(q, conn);
conn.Open();
string user = "";
MySqlDataReader rdr = cmd.ExecuteReader();
while (rdr.Read())
{
user = rdr.GetString("username");
DropDownListSelectEmployee.Items.Add(user);
}
conn.Close();
}
}
怎么可能?
假设您不想选择任何名称,请使用:
使用DropDownListSelectEmployee.SelectedIndex = -1;
但是,如果要在顶部放置一个命名框,只需将其添加为列表的第一项,并将其作为所选索引即可。
像这样:
DropDownListSelectEmployee.Items.Add("nWorks User");
while (rdr.Read())
{
user = rdr.GetString("username");
DropDownListSelectEmployee.Items.Add(user);
}
您需要将第一个项目添加到循环之外,然后默认情况下将选择该第一个项目。
DropDownListSelectEmployee.DataSource = table;
DropDownListSelectEmployee.DataTextField = "Name";
DropDownListSelectEmployee.DataValueField = "Id";
DropDownListSelectEmployee.DataBind();
DropDownListSelectEmployee.Items.Insert(0, new ListItem("--nworks User--", "0"));
<asp:DropDownList runat="server" ID="DropDownListSelectEmployee"OnSelectedIndexChanged="DropDownListSelectEmployee_SelectedIndexChanged" AutoPostBack="true"
OnTextChanged="DropDownListSelectEmployee_TextChanged" Height="30px" Width="250px">
</asp:DropDownList>
后面的代码:protected void Page_Load(object sender,EventArgs e){if(!Page.IsPostBack){BindDropdwon(); }}
protected void DropDownListSelectEmployee_SelectedIndexChanged(object sender, EventArgs e)
{
}
protected void DropDownListSelectEmployee_TextChanged(object sender, EventArgs e)
{
}
private void BindDropdwon()
{
DataTable table = new DataTable();
table.Columns.Add("Id", typeof(int));
table.Columns.Add("Name", typeof(string));
// Here we add three DataRows.
table.Rows.Add(25, "Indocin");
table.Rows.Add(50, "Enebrel");
table.Rows.Add(10, "Hydralazine");
DropDownListSelectEmployee.DataSource = table;
DropDownListSelectEmployee.DataTextField = "Name";
DropDownListSelectEmployee.DataValueField = "Id";
DropDownListSelectEmployee.DataBind();
***DropDownListSelectEmployee.Items.Insert(0, new ListItem("--nworks User--", "0"));***
}
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.