Web Controls Dynamisch Erzeugen / Web Page Lebenszyklus

Controls immer in PreInit erzeugen (vorher werden die durch den aspx html angegebenen controls erzeugt), dannach werden sie in Init initialisiert (also z.b. Viewstate=Value reingeschrieben ...)


Ein Beispiel mit DropDowns:

public partial class _Default : System.Web.UI.Page
{
//Lebenszyklus: http://msdn.microsoft.com/en-us/library/ms178472.aspx
//Page_PreInit
//Page_Init
//Page_InitComplete
//Page_Load

const int ddlMax=9;
DropDownList[] ddls = new DropDownList[ddlMax];

protected void Page_PreInit(object sender, EventArgs e)
{
/*
Raised after the start stage is complete and before the initialization stage begins.
Use this event for the following:
Check the IsPostBack property to determine whether this is the first time the page is being processed. The IsCallback and IsCrossPagePostBack properties have also been set at this time.
Create or re-create dynamic controls.
Set a master page dynamically.
Set the Theme property dynamically.
Read or set profile property values.

Note
If the request is a postback, the values of the controls have not yet been restored from view state. If you set a control property at this stage, its value might be overwritten in the next event.
*/

for (int i = 0; i < ddlMax; i++)
{
DropDownList ddlx = new DropDownList();
ddlx.ID = "ddl"+i.ToString();
for (int item = 0; item < i; item++)
{
ddlx.Items.Add(ddlx.ID + item.ToString());
}
form1.Controls.Add(ddlx);
ddls[i] = ddlx;
//panDDLs.Controls.Add(ddlx);

}
}
protected void Page_Init(object sender, EventArgs e)
{
/*
* Raised after all controls have been initialized and any skin settings have been applied. The Init event of individual controls occurs before the Init event of the page.
Use this event to read or initialize control properties.
*/
}
protected void Page_InitComplete(object sender, EventArgs e)
{
}
protected void Page_PreLoad(object sender, EventArgs e)
{
}
protected void Page_Load(object sender, EventArgs e)
{

Response.Write("

---

DropDownValues
");
for (int i = 0; i < ddlMax; i++)
{
Response.Write("ddl Nr.:" + i.ToString() + " value=" + ddls[i].SelectedValue+"
");
}
}
// ------------------ Control Events -------------------
protected void Page_LoadComplete(object sender, EventArgs e)
{
}
protected void Page_PreRender(object sender, EventArgs e)
{
}
protected void Page_PreRenderComplete(object sender, EventArgs e)
{
}
protected void Page_SaveStateComplete(object sender, EventArgs e)
{
}
protected void Page_Render(object sender, EventArgs e)
{
}
protected void Page_Unload(object sender, EventArgs e)
{
}

}