public async override void Execute(object parameter)
{
base.Execute(parameter);
LoadMoreDataContext context = (LoadMoreDataContext)parameter;
LoadOnDemandCommand.ViewModel viewModel = (LoadOnDemandCommand.ViewModel)context.DataContext;
this.lodCounter++;
if (this.lodCounter % 3 == 0)
{
// If we do not need to get new data asynchronously, we can add the new items right away.
viewModel.AddItems(15);
}
else
{
// If we need to get new data asynchronously, we must manually update the loading status.
this.Owner.ChangeDataLoadingStatus(BatchLoadingStatus.ItemsRequested);
// Mimic getting data from server asynchronously.
await Task.Delay(2000);
viewModel.AddItems(15);
this.Owner.ChangeDataLoadingStatus(BatchLoadingStatus.ItemsLoaded);
}
}
/// <summary>
/// Defines the method to be called when the command is invoked.
/// </summary>
/// <param name="parameter">
/// The parameter used by the command.
/// </param>
public void Execute(object parameter)
{
RadListView listView = this.LoadDataControl.Owner;
LoadMoreDataContext context = new LoadMoreDataContext {
View = listView, DataContext = listView.DataContext
};
listView.CommandService.ExecuteCommand(Commands.CommandId.LoadMoreData, context);
}
public override bool CanExecute(object parameter)
{
LoadMoreDataContext context = (LoadMoreDataContext)parameter;
LoadOnDemandCommand.ViewModel viewModel = (LoadOnDemandCommand.ViewModel)context.DataContext;
bool canExecute = viewModel.Items.Count < 100;
return(canExecute);
}
internal RadSize MeasureContent(RadSize newAvailableSize)
{
var size = this.layoutController.MeasureContent(newAvailableSize);
if (this.ShouldAutoRequestItems(null))
{
LoadMoreDataContext context = new LoadMoreDataContext {
View = this.View, DataContext = this.View.GetDataContext()
};
this.View.CommandService.ExecuteCommand(CommandId.LoadMoreData, context);
}
// NOTE: If we decide that we won't zero the length of collapsed rows then this 'TotalLineCount - 1' will be incorrect.
// this.desiredSize = new RadSize(this.columnLayout.RenderInfo.OffsetFromIndex(this.columnLayout.TotalLineCount - 1), this.rowLayout.RenderInfo.OffsetFromIndex(this.rowLayout.TotalLineCount - 1));
// return this.desiredSize;
return(size);
}
