Sqldatasource updating cancel
Binding a Grid View control can sometimes get tricky when using the Visual Studio editor, especially when working with Drop Down List controls within the grid. Today I was working on getting a row of the Grid View control to save the contents of a Drop Down List, and needed to add some custom code to set values passed to the Sql Data Source control on the update event. I found that simple data binding of my Drop Down List in my Grid View to my Sql Data Source was not going to be enough. I would need to set values passed to the Sql Data Source control on the update event, and as part of this I would need to reference the controls contained in the row being updated. The pre- and post-action event handlers are also quite helpful when debugging. These controls allow page developers to declaratively access and modify data without writing any code to perform the data access. This article is one in a series of articles on ASP. When retrieving or modifying data with the Sql Data Source or Object Data Source controls, pre- and post-action events fire.By creating event handlers for these events, we can examine the underlying workflow, massage the inputs, and examine the results.
Binding form controls is mostly a simple matter of attaching a Data Source and setting your controls to reference the correct field in the Data Source.
Many real-world scenarios require that the parameters being used for selecting, inserting, updating, or deleting be programmatically assigned or altered, which can be accomplished in the appropriate pre-action event.
Moreover, to gracefully handle database- or object library-level exceptions in the page, the post-action event handlers should be used.
NET 2.0 introduced a number of new Web controls designed for accessing and modifying data. NET 2.0 provide a simple, declarative approach for accessing and modifying data.
These controls allow page developers to declaratively access and modify data without writing any code to perform the data access. The Data Source Control Basics article that kicked off this article series examined how to add data source controls to a page, specify the data to retrieve and/or modify, and bind that data to a data Web control (such as a Grid View, Details View, or Form View).
The events are aptly named in the past and present tenses of the methods. While the concepts are the same for the Sql Data Source and Object Data Source controls, the implementation details differ.