Question

所以我一直试图让它异步下载images.my app运行缓慢，滞后和延迟

public override View GetView(int position, View convertView,ViewGroup parent)
    			{
    				View view = convertView ?? _inflater.Inflate (Resource.Layout.textViewItems, parent, false);

    				
    				if (track.artwork_url != null) {


    					var imageBitmap = GetImageBitmapFromUrl(track.artwork_url);
    					if (imageBitmap != null && imageBitmap.Length > 0) {
    						var converterImage = BitmapFactory.DecodeByteArray (imageBitmap, 0, imageBitmap.Length);
    						viewHolder.Image.SetImageBitmap(converterImage);
    					}

    				} else {
    					viewHolder.Image.SetImageResource(Resource.Drawable.img1);
    				}


    				return view;
    			}

public static byte[] GetImageBitmapFromUrl(string url)
		{
			byte [] imageBitmap = null;

			using (var webClient = new WebClient())
			{
				var imageBytes = webClient.DownloadData(url);

				imageBitmap = imageBytes;
			}


			return imageBitmap;
	}

所有图像都以listview（100px高度和宽度）加载。我也设置了ImageView.layout_width = 70dp和高度。但我不能在列表视图中向下或向上滚动。因为listview变得如此滞后和非常糟糕

我认为问题在于GetImageBitmapFromUrl。如何解决。

Answer 1

您可以使用MonoDroid.UrlImageViewHelper异步加载图片。

    if (track.artwork_url != null) {
            viewHolder.Image.SetUrlDrawable(track.artwork_url, Resource.Drawable.img1);
    }

您可以在Xamarin论坛上查看更多详细信息：ListView - Asynchronous Image Loading (from URL)

Listview在从互联网上加载20张图片时运行如此滞后

1 个答案: