How to get DataGrid SelectionChanged trigger source component?

Question

I have a ComboBox binded to an object that is also binded to a DataGrid. When I change the ComboBox selection or the SelectedItem in the DataGrid the event SelecionChanged at the ComboBox is triggered.

Is there a way to know which component (DataGrid or ComboBox) has triggered the event?

Answer 1

In order for the ComboBox to post back, I'd imagine it's set to AutoPostBack? If this affects the data on the GridView at all, then all events will fire. When a full postback is triggered (such as with the ComboBox set to AutoPostBack=true), every event with new data is fired.

You should look into the control lifecycle: http://msdn.microsoft.com/en-us/library/aa719775(v=vs.71).aspx (this is just the msdn doc, it's not great, but it's a good starting point).

...You should also try and post some code with your question :) It's a little ambiguous what you're doing. What object are they both bound to? Or is the same dataset bound to both the GridView and ComboBox?

EDIT: This post might help a little: Two types of postback events

Answer 2

如果我是您，我会将断点放置在SelectedItem或SelectedChanged断点处，并尝试在调试模式下运行解决方案，并查看击中第一个断点的位置；）Callstack也会为您提供帮助。

Answer 3

Assuming you have them both hooked up to a object data source. You can just create a seperate data source for your drop down that uses the same SelectMethod. That way they both get updated with the same data after a postback.

Otherwise Use javascript for the onchange event of the drop down and set a hidden field with if was changed or not. Then check that value to see if it was from the drop down or not.

<asp:DropDownList runat="server" ID="drpOption"onchange="javascript:OptionChanged();"></asp:DropDownList>

function OptionChanged() {
    $('#hdnField').val = 'true';

    return false;
}

Answer 4

您可以通过应用首先执行的BreakPoint来使DAtaGRid和Combobox ANd检查选择更改事件。