What is trigger in UpdatePanel?
Triggers for a given UpdatePanel, by default, automatically include any child controls that invoke a postback, including (for example) TextBox controls that have their AutoPostBack property set to true.
What is an UpdatePanel control?
UpdatePanel controls work by specifying regions of a page that can be updated without refreshing the whole page. This process is coordinated by the ScriptManager server control and the client PageRequestManager class. When partial-page updates are enabled, controls can asynchronously post to the server.
How many types of triggers are present in UpdatePanel?
Answer: There are 2 types of triggers.
What is async postback trigger?
Converts postbacks into async callbacks Typically used to trigger updates when controls outside an UpdatePanel post back If ChildrenAsTriggers=”false”, can be used to specify which controls inside UpdatePanel should call back rather than post back.
What is postback trigger in UpdatePanel?
Remarks. Use the PostBackTrigger control to enable controls inside an UpdatePanel to cause a postback instead of performing an asynchronous postback. You can then call the Update method of the UpdatePanel control when the trigger control performs a postback.
How do I stop UpdatePanel from refreshing?
The only possible way is to place the DropDownList inside ASP.Net AJAX UpdatePanel so that, instead of Full PostBack which causes Page refresh (reload), a Partial PostBack will occur. The HTML Markup consists of an ASP.Net ScriptManager and a DropDownList placed inside AJAX UpdatePanel.
What is UpdateMode in UpdatePanel?
If the UpdateMode property is set to Always, the UpdatePanel control’s content is updated on every postback that originates from anywhere on the page. This includes asynchronous postbacks from controls inside other UpdatePanel controls and postbacks from controls that are not inside UpdatePanel controls.
What is ChildrenAsTriggers in UpdatePanel?
The ChildrenAsTriggers property determines whether postbacks from a child ontrol in an UpdatePanel result in its contents being refreshed. By default, this property is set to True and can be set to False only when the UpdateMode is set to conditional.
How do I stop the page refresh from selecting the DropDownList?
How to define triggers in the UpdatePanel control?
The Triggers property gets a collection of all the triggers that have been defined for the UpdatePanel control. (You can define triggers declaratively by using the UpdatePanelTrigger Collection Editor dialog box in the designer or by using the element of the UpdatePanel control.)
Which is the trigger element in Ajax UpdatePanel?
One of which is the Triggers element, which specifies the controls on the page (or the user control, if you are using one) that will trigger a partial render of the UpdatePanel control in which the element resides.
What are the child tags in Ajax UpdatePanel?
Ajax updatepanel control contains two child tags those are ContentTemplate and Triggers. Triggers we used in a situation like need to refresh updatepanel only whenever I click some button control in that situation I will define those controls with this Triggers child tag.
Where does the asyncpostbacktrigger reference the control?
The control that the AsyncPostBackTrigger references must be in the same naming container as the update panel for which it is a trigger. Triggers that are based on controls in other naming containers are not supported. The workaround is to use the UniqueID of the control that the trigger is referencing.