问题
I have a paged ASP.NET ListView. The data shown is filtered, which can be controlled by a form. When the filter form changes, I create a new query, and perform a DataBind.
The problem however, when I go to the next page, and set a filter, the ListView shows "No data was returned". That is not weird, because after the filter is applied, there is only one page of data.
So what I want to do is reset the pager. Is that a correct solution to the problem? And how do I do that?
回答1:
I use this hack in my Load handler. It'll not reset the pager if the number of result items is the same, but the page index will still be valid so I can live with that for now.
if (IsPostBack)
{
DataPager pgr = MyListView.FindControl("MyPager") as DataPager;
if (pgr != null && MyListView.Items.Count != pgr.TotalRowCount)
{
pgr.SetPageProperties(0, pgr.MaximumRows, false);
}
}
回答2:
If you know how to do it, it is simple. I added the code below to my onchange
-events of my filter:
DataPager pager = ListViewReference.FindControl("DataPagerId") as DataPager;
if (pager != null)
{
pager.SetPageProperties(0, pager.PageSize, true);
}
回答3:
Either of the above solutions are correct as they both call the same method. I just think it should be pointed out that you should call yourPagerElement.SetPageProperties(...)
wherever you want your datasource (ie a list or an array, etc.) to be updated. For example, after applying some filtration or something that greatly changes the list size.
回答4:
You may have problems if your listview is automatically bounded (i.e. ObjectDataSource)
Load event handler doesn't work, because you haven't yet the new DataPager.TotalRowPage value, but you can handle Page_PreRenderComplete, like this:
protected void Page_PreRenderComplete(object sender, EventArgs e)
{
// PreRenderComplete occurs just after databindings page events
// And saves to viewstate
// Trick on search to avoid "No data" on results when old page is greater than actual row count
if (DataPager1.StartRowIndex > DataPager1.TotalRowCount )
DataPager1.SetPageProperties(0, DataPager1.MaximumRows, true);
}
This always leaves ListView in a page with data. If page is greater than TotalRow, switch to first page.
Notes: I'm using efective paging, and returning only the data to be displayed, so I need to rebind de datasource (last parameter (true))
Cons: Double databind if StartRowIndex is greater than TotalRowCount.
来源:https://stackoverflow.com/questions/2849449/how-to-force-listview-to-show-first-page-programmatically