我有一个DropDown绑定到一个ObjectDataSource。在其数据绑定事件上,我在0索引上添加了“--select--”值。我有一个LinkButton在页面上和客户端点击,我选择不同的项目下拉(使用JavaScript)。假设有3个项目,如--select--,option1,option2和option3,现在链接按钮的客户端上单击我选择的选项3,现在如果我选择默认值“--select--”,它不会触发SelectedIndexChanged事件。如果我选择任何其他值,那么它会触发。为什么它不适用于默认值?为什么DropDownList.SelectedIndexChanged事件不会触发?
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack && !IsCallback)
{
this.FillDropDown("--Select--");
}
else
{
if (this.drp.SelectedItem != null)
this.FillDropDown(this.drp.SelectedItem.Text);
else
this.FillDropDown("--Select--");
}
}
protected void FillDropDown(string viewName)
{
this.obJectDataSource.Select();
this.drp.Items.Clear();
this.drp.SelectedIndex = -1;
this.drp.DataBind();
if (this.drp.Items.Count > 0)
{
ListItem item = this.drp.Items.FindByText(viewName);
if (item == null)
{
item = this.drp.Items.FindByText("--Select--");
}
if (item != null)
{
int selectedIndex = this.drp.Items.IndexOf(item);
this.drp.Items[selectedIndex].Selected = true;
this.drp.SelectedIndex = selectedIndex;
}
}
}
protected void drp_OnDataBound(object sender, EventArgs e)
{
if (this.drp.Items.Count > 0)
{
this.drp.Items.Insert(0, new ListItem("--Select--", "-1"));
}
}
protected void drp_SelectedIndexChanged(object sender, EventArgs e)
{
if (drp.SelectedValue != "-1")
{
Session["SelectedItem"] = this.drp.SelectedItem.Text;
}
}
/// The button which do callback not postback
<dx:ASPxCallback ID="ASPxCallback1" runat="server" ClientInstanceName="Callback1" OnCallback="SaveFilter_Click">
<ClientSideEvents CallbackComplete="function(s,e){Callback1Success(s,e);}" />
</dx:ASPxCallback>
<dx:ASPxButton ID="btn_Save" runat="server" CausesValidation="False" Height="20px" Text="Save" AutoPostBack="false" UseSubmitBehavior="false">
<ClientSideEvents Click="function(s, e) {
var isValid = Validate(this, txt1.GetText());
if(isValid==true) {
Callback1.PerformCallback('Save');
}
else {
e.processOnServer = false;
}}">
</ClientSideEvents>
</dx:ASPxButton>
protected void SaveFilter_Click(object sender, CallbackEventArgs e)
{
if (e.Parameter.ToString() == "Save")
{
if (!string.IsNullOrEmpty(txt_SaveSaveSearch.Text))
{
// saving data into data base.
this.FillDropDown(txt.Text);
e.Result = ASPxCallback.GetRenderResult(this.drp);
}
}
}
function Callback1Success(s,e) {
var ctrl = document.getElementById('ctl00_ContentHolder_drp');
ctrl.outerHTML = e.result;
}
你可以发布.net代码的下拉菜单吗? – Hawxby 2011-02-09 10:53:05
发布您的标记和代码隐藏。什么是负责添加 - 选择 - ? – 2011-02-09 11:03:04
检查自动回复并启用视图状态属性设置为真 – Dotnet 2011-02-09 12:57:11