DropDownList控件绑定数据库后，下拉列表没有内容？？！！
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
Message get = new Message();
DataSet set = get.GetMessage();
this.DropDownList1.DataSource = set;
this.DropDownList1.DataValueField = "ID";
this.DropDownList1.DataTextField = "Title";
this.DropDownList1.DataBind();
}
}
-----------------------------------------------------------------
public DataSet GetMessage()
{
string connectionString = ConfigurationManager.ConnectionStrings["SQLCONNECTIONSTRING"].ConnectionString;
SqlConnection con = new SqlConnection(connectionString);
string cmdText = "select Title,ID from Message";
SqlDataAdapter sda = new SqlDataAdapter(cmdText,con);
DataSet ds = new DataSet();
try
{
con.Open();
sda.Fill(ds);
}
finally
{
con.Close();
}
return ds;
}
调试时，DropDownList下拉列表没有内容，请各位高手指点！！（数据库连接是没有问题的。）
[解决办法]
1.我想问，你加载的时候下拉根本没有绑定任何东西，那么 DropDownList1_SelectedIndexChanged 这个有什么用，无语
这样写：
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)//首次加载时绑定
{
Message get = new Message();
DataSet set = get.GetMessage();
this.DropDownList1.DataSource = set;
this.DropDownList1.DataValueField = "ID";
this.DropDownList1.DataTextField = "Title";
this.DropDownList1.DataBind();
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
//改变选择后，执行其他操作
}
[解决办法]
if (!Page.IsPostBack)
{
Message get = new Message();
DataSet set = get.GetMessage();
this.DropDownList1.DataSource = set;
this.DropDownList1.DataValueField = "ID";
this.DropDownList1.DataTextField = "Title";
this.DropDownList1.DataBind();
DropDownList1.Items.Insert(0, "请选择");
}
