/// <summary>
/// Called when the dialog is started and pushed onto the dialog stack.
/// </summary>
/// <param name="dc">The <see cref="DialogContext"/> for the current turn of conversation.</param>
/// <param name="options">Optional, initial information to pass to the dialog.</param>
/// <param name="cancellationToken">A cancellation token that can be used by other objects
/// or threads to receive notice of cancellation.</param>
/// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
public override async Task <DialogTurnResult> BeginDialogAsync(DialogContext dc, object options = null, CancellationToken cancellationToken = default(CancellationToken))
{
if (options is CancellationToken)
{
throw new ArgumentException($"{nameof(options)} cannot be a cancellation token");
}
if (Disabled != null && Disabled.GetValue(dc.State))
{
return(await dc.EndDialogAsync(cancellationToken : cancellationToken).ConfigureAwait(false));
}
dc.State.SetValue(PageIndex.GetValue(dc.State), 0);
return(await NextPageAsync(dc, cancellationToken).ConfigureAwait(false));
}
private async Task <DialogTurnResult> NextPageAsync(DialogContext dc, CancellationToken cancellationToken)
{
int pageIndex = dc.State.GetIntValue(PageIndex.GetValue(dc.State), 0);
int pageSize = this.PageSize.GetValue(dc.State);
int itemOffset = pageSize * pageIndex;
var itemsProperty = this.ItemsProperty.GetValue(dc.State);
if (dc.State.TryGetValue <object>(itemsProperty, out object items))
{
var page = this.GetPage(items, itemOffset, pageSize);
if (page.Any())
{
dc.State.SetValue(Page.GetValue(dc.State), page);
dc.State.SetValue(PageIndex.GetValue(dc.State), ++pageIndex);
return(await this.BeginActionAsync(dc, 0, cancellationToken).ConfigureAwait(false));
}
}
// End of list has been reached
return(await dc.EndDialogAsync(cancellationToken : cancellationToken).ConfigureAwait(false));
}
