asp.net - 下拉列表中的第一项为空白

Question

如何将 DropDownList 上的第一项设为空白？在 VB 中类似于，DropDownList.index[0] = ""; 我这样做了:

string StrConn = ConfigurationManager.ConnectionStrings["connSql"].ConnectionString;
    SqlConnection conn = new SqlConnection(StrConn);

    conn.Open();

    SqlDataReader dr;

    string sql;
    sql = @"Select Nome From DanielPessoas";

    SqlCommand cmd = new SqlCommand(sql, conn);
    dr = cmd.ExecuteReader();

    DropDownList1.DataSource = dr;
    DropDownList1.DataTextField = "Nome";
    DropDownList1.DataValueField = "Nome";
    DropDownList1.DataBind(); 

Answer 1

在 DataBind 调用之后，添加此代码。

DropDownList1.Items.Insert(0, new ListItem(string.Empty, string.Empty));