private async void tryStart()
{
if (processing < config.ThreadPoolSize)
{
if (queue.Count > 0)
{
processing++;
ImageLoaderQueueItem item = null;
if (config.QueueProcessingType == QueueProcessingType.FIFO)
{
item = queue[0];
}
else
{
item = queue[queue.Count - 1];
}
await doProcess(item);
queue.Remove(item);//处理完了后，再删除
processing--;
tryStart();//[触发2]每完成一个任务后尝试启动新任何
}
}
}
private void doShow(ImageLoaderQueueItem item, BitmapImage image)
{
if (item.View != null && image != null)
{
Util.call(() =>
{
item.View.Source = image;
});
}
if (item.Listener != null)
{
Util.call(() =>
{
if (image == null)
{
item.Listener(LoadingState.Failed, item.Url, item.View, image);
}
else
{
item.Listener(LoadingState.Completed, item.Url, item.View, image);
}
});
}
}
public ImageLoaderQueueItem DownloadImage(string url, DisplayImageOptions options, ImageLoadingListener listener) {
if (string.IsNullOrEmpty(url))
return null;
var item = new ImageLoaderQueueItem() { Url = url, Options = options, View = null, Listener = listener };
return add(item);
}
private async Task doSave(ImageLoaderQueueItem item, IBuffer buffer)
{
if (buffer == null)
{
return;
}
if (item.Options.CacheOnDisk)
{
await config.DiskCache.Save(item.Url, buffer);
}
}
public ImageLoaderQueueItem DownloadImage(string url, DisplayImageOptions options, ImageLoadingListener listener)
{
if (string.IsNullOrEmpty(url))
{
return(null);
}
var item = new ImageLoaderQueueItem()
{
Url = url, Options = options, View = null, Listener = listener
};
return(add(item));
}
private async Task doProcess(ImageLoaderQueueItem item)
{
IBuffer buffer = null;
BitmapImage image = null;
if (buffer == null)
{
item.Listener(LoadingState.Started, item.Url, item.View, null);
buffer = await config.ImageDownloader.download(item.Url, item.Options.ExtraForDownloader);
image = await doDecode(item, buffer);
await doSave(item, buffer);
}
doShow(item, image);
}
//---------
private ImageLoaderQueueItem add(ImageLoaderQueueItem item)
{
item.Code = item.Url.GetHashCode();
if (queue.FirstOrDefault(m => m.Code == item.Code) != null)
{
if (item.Listener != null)
{
item.Listener(LoadingState.Cancelled, item.Url, item.View, null);
}
return(item);
}
doTryAdd(item);
return(item);
}
private async Task <BitmapImage> doDecode(ImageLoaderQueueItem item, IBuffer buffer)
{
if (buffer != null)
{
try {
InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream();
DataWriter datawriter = new DataWriter(stream.GetOutputStreamAt(0));
datawriter.WriteBuffer(buffer, 0, buffer.Length);
await datawriter.StoreAsync();
BitmapImage image = new BitmapImage();
image.SetSource(stream);
return(image);
}
catch { }
}
return(null);
}
private async void doTryAdd(ImageLoaderQueueItem item)
{
if (item.Options.CacheOnDisk)
{
if (config.DiskCache != null)
{
var buffer = await config.DiskCache.Get(item.Url);
var image = await doDecode(item, buffer);
if (buffer != null)
{
doShow(item, image);
return;
}
}
}
queue.Add(item); //
tryStart(); //[触发1]每次添加都尝试启动任务
}
private void DoUpdateSourceAsync()
{
if (Src == null || Src.Scheme == null)
{
return;
}
if (Src.Scheme.IndexOf("http") < 0) //如果不是http地址
{
view.Source = new BitmapImage(Src);
}
else //如果是http地址
{
view.Source = null;
var loader = CurrentLoader();
loadingItem = loader.DownloadImage(Src.AbsoluteUri, (state, url, v, image) =>
{
if (_isLoaded && state == LoadingState.Completed)
{
view.Source = image;
}
});
}
}
private async Task<BitmapImage> doDecode(ImageLoaderQueueItem item, IBuffer buffer) {
if (buffer != null) {
try {
InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream();
DataWriter datawriter = new DataWriter(stream.GetOutputStreamAt(0));
datawriter.WriteBuffer(buffer, 0, buffer.Length);
await datawriter.StoreAsync();
BitmapImage image = new BitmapImage();
image.SetSource(stream);
return image;
}
catch { }
}
return null;
}
private async Task doSave(ImageLoaderQueueItem item, IBuffer buffer) {
if (buffer == null)
return;
if (item.Options.CacheOnDisk) {
await config.DiskCache.Save(item.Url, buffer);
}
}
private void doShow(ImageLoaderQueueItem item, BitmapImage image) {
if (item.View != null && image != null) {
Util.call(() =>
{
item.View.Source = image;
});
}
if (item.Listener != null) {
Util.call(() =>
{
if (image == null)
item.Listener(LoadingState.Failed, item.Url, item.View, image);
else
item.Listener(LoadingState.Completed, item.Url, item.View, image);
});
}
}
private async Task doProcess(ImageLoaderQueueItem item) {
IBuffer buffer = null;
BitmapImage image = null;
if (buffer == null) {
item.Listener(LoadingState.Started, item.Url, item.View, null);
buffer = await config.ImageDownloader.download(item.Url, item.Options.ExtraForDownloader);
image = await doDecode(item, buffer);
await doSave(item, buffer);
}
doShow(item, image);
}
private async void doTryAdd(ImageLoaderQueueItem item) {
if (item.Options.CacheOnDisk) {
if (config.DiskCache != null) {
var buffer = await config.DiskCache.Get(item.Url);
var image = await doDecode(item, buffer);
if (buffer != null) {
doShow(item, image);
return;
}
}
}
queue.Add(item); //
tryStart();//[触发1]每次添加都尝试启动任务
}
public void Remove(ImageLoaderQueueItem item)
{
queue.Remove(item);
}
public void Remove(ImageLoaderQueueItem item) {
queue.Remove(item);
}
//---------
private ImageLoaderQueueItem add(ImageLoaderQueueItem item) {
item.Code = item.Url.GetHashCode();
if (queue.FirstOrDefault(m => m.Code == item.Code) != null) {
if (item.Listener != null) {
item.Listener(LoadingState.Cancelled, item.Url, item.View, null);
}
return item;
}
doTryAdd(item);
return item;
}
private void DoUpdateSourceAsync() {
if (Src == null || Src.Scheme == null)
return;
if (Src.Scheme.IndexOf("http") < 0) {//如果不是http地址
view.Source = new BitmapImage(Src);
}
else {//如果是http地址
view.Source = null;
var loader = CurrentLoader();
loadingItem = loader.DownloadImage(Src.AbsoluteUri, (state, url, v, image) =>
{
if (_isLoaded && state == LoadingState.Completed) {
view.Source = image;
}
});
}
}
