c# - 数据未通过回发加载到页面加载中

Question

我有一个问题。页面加载后数据未加载。我必须在下拉列表中选择一个项目才能加载。在我选择下拉列表中的任何项目之前，我需要加载它。

这是我的代码。

 protected void ddlPeriodStamp_SelectedIndexChanged(object sender, System.EventArgs e)
{
    string selectedGroup = string.Empty;
    DropDownList ddlItemGroup = (DropDownList)sender;

    if (ddlItemGroup.SelectedValue != null)

        TreatmentGroup = ddlItemGroup.SelectedValue;
        ApplyGridFilter(ddlItemGroup.SelectedValue);


}

protected void ApplyGridFilter(string TreatmentGroup)
{
    string selectedGroup = string.Empty;
    DBDataSource1.State.BusinessObject.DataPump.FormFilters.Clear();
    DBDataSource1.State.BusinessObject.DataPump.FormFilters.Add("TreatmentGroup", TreatmentGroup);
    DBDataSource1.State.BusinessObject.Fill(null);
    MedicalSchemeDetailGrid.DataBind();
}
protected void Page_LoadComplete(object sender, System.EventArgs e)
{

    if (!this.IsPostBack)
            ApplyGridFilter(string.Empty);
}

Answer 1

当 ispostBack 为 false 时调用 ApplyGridFilter(string.Empty); 并在 ispostBack 时调用 ApplyGridFilter(ddlItemGroup.SelectedValue); 为真

protected void Page_LoadComplete(object sender, System.EventArgs e)
 {

   if (this.IsPostBack)
   {
     ApplyGridFilter(ddlItemGroup.SelectedValue);// it will hit on first time page load 
   }
   else
   {
     ApplyGridFilter(string.Empty);// it will hit while you change the dropdown items, But you should set true for **IsAutoPostBack** property on dropsownlist.    
   }
 }