protected async Task <LoadMoreItemsResult> LoadMoreItemsAsync(CancellationToken c, uint count)
{
try
{
OnLoadMoreStarted?.Invoke(count);
// 我们忽略了CancellationToken，因为我们暂时不需要取消，需要的可以加上
var result = await _dataFetchDelegate(count);
var items = result;
if (items != null)
{
foreach (var item in items)
{
Add(item);
}
}
// 加载完成事件
OnLoadMoreCompleted?.Invoke(items?.Count ?? 0);
return(new LoadMoreItemsResult {
Count = items == null ? 0 : (uint)items.Count
});
}
finally
{
Busy = false;
}
}
protected async Task <LoadMoreItemsResult> LoadMoreItemsAsync(CancellationToken c, uint count)
{
if (!HasMoreItems)
{
return new LoadMoreItemsResult {
Count = 0
}
}
;
if (_dataFetchDelegate == null)
{
throw new NotImplementedException("IncrementalCollection's delegate is null");
}
try {
OnLoadMoreStarted?.Invoke((int)count);
//忽略了CancellationToken
var result = await this._dataFetchDelegate(count);
var items = result.Item1;
if (items != null)
{
foreach (var item in items)
{
this.Add(item);
}
}
// 是否还有更多
this.HasMoreItems = result.Item2;
// 加载完成事件
OnLoadMoreCompleted?.Invoke(items == null ? 0 : items.Count);
return(new LoadMoreItemsResult {
Count = items == null ? 0 : (uint)items.Count
});
}
finally {
_busy = false;
}
}
}
protected async Task <LoadMoreItemsResult> LoadMoreItemsAsync(CancellationToken c, uint count)
{
var dispatcherQueue = Windows.System.DispatcherQueue.GetForCurrentThread();
try
{
OnLoadMoreStarted?.Invoke(count);
// 我们忽略了CancellationToken，因为我们暂时不需要取消，需要的可以加上
var result = await _dataFetchDelegate(count);
var items = result.Item1;
if (items != null)
{
await dispatcherQueue.EnqueueAsync(() =>
{
foreach (var item in items)
{
Add(item);
}
});
}
// 是否还有更多
HasMoreItems = result.Item2;
// 加载完成事件
OnLoadMoreCompleted?.Invoke(items == null ? 0 : items.Count);
return(new LoadMoreItemsResult {
Count = items == null ? 0 : (uint)items.Count
});
}
finally
{
await dispatcherQueue.EnqueueAsync(() =>
{
IsBusy = false;
});
}
}
private async Task <LoadMoreItemsResult> LoadMoreItemsInternal(CancellationToken c, uint count)
{
try
{
// 加载开始事件
OnLoadMoreStarted?.Invoke(this, count);
var items = await LoadMoreItemsAsync(c, count);
AddRange(items);
// 加载完成事件
OnLoadMoreCompleted?.Invoke(this, (uint)(items?.Count() ?? 0));
return(new LoadMoreItemsResult {
Count = (uint)(items?.Count() ?? 0)
});
}
finally
{
_busy = false;
}
}
