如何通过网络加载多个图片到ImageView并提升性能

huangapple
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英文:

How to boost to load multiple images from web to ImageViews

问题

以下是您要求的翻译内容：

要从网站加载多个图像，编写了以下代码。

  1. public void connectImgtoView(final int max) {
  3.     new Thread(new Runnable() {
  4.         @Override
  5.         public void run() {
  6.             URL url = null;
  7.             for (int i = 0; i < max; i++) {
  8.                 try {
  9.                     url = new URL(postImgUrl.get(i));
  10.                 } catch (MalformedURLException e) {
  11.                     e.printStackTrace();
  12.                 }
  14.                 try {
  15.                     final BufferedInputStream bufferedInputStream
  16.                             = new BufferedInputStream(url.openStream());
  17.                     Bitmap bitmap = BitmapFactory.decodeStream(bufferedInputStream);
  18.                     bufferedInputStream.close();
  20.                     final Bitmap scaledBitmap = Bitmap.createScaledBitmap(
  21.                             bitmap,
  22.                             (int) (992),
  23.                             (int) (1403),
  24.                             true
  25.                     );
  27.                     final int finalI = i;
  28.                     runOnUiThread(new Runnable() {
  29.                         @Override
  30.                         public void run() {
  31.                             postImg[finalI].setImageBitmap(scaledBitmap);
  32.                         }
  33.                     });
  34.                 } catch (IOException e) {
  35.                     e.printStackTrace();
  36.                 }
  37.             }
  38.             progressOFF();
  39.         }
  40.     }).start();
  41. }

尽管这种方法执行成功，但存在性能速度过慢的问题。

因此，我想知道有什么方法比这个更快。

请帮忙。

变量说明

postImgUrl：类型为 ArrayList，这是我想要的图像的 URL。

postImg：类型为 ImageView 数组，这是布局中存在的 ImageView。

英文:

To load several images from a website, the following code was written.

  1.     public void connectImgtoView(final int max) {
  3.         new Thread(new Runnable() {
  4.             @Override
  5.             public void run() {
  6.                 URL url = null;
  7.                 for (int i = 0; i &lt; max; i++) {
  8.                     try {
  9.                         url = new URL(postImgUrl.get(i));
  10.                     } catch (MalformedURLException e) {
  11.                         e.printStackTrace();
  12.                     }
  14.                     try {
  15.                         final BufferedInputStream bufferedInputStream
  16.                                 = new BufferedInputStream(url.openStream());
  17.                         Bitmap bitmap = BitmapFactory.decodeStream(bufferedInputStream);
  18.                         bufferedInputStream.close();
  20.                         final Bitmap scaledBitmap = Bitmap.createScaledBitmap(
  21.                                 bitmap,
  22.                                 (int) (992),
  23.                                 (int) (1403),
  24.                                 true
  25.                         );
  27.                         final int finalI = i;
  28.                         runOnUiThread(new Runnable() {
  29.                             @Override
  30.                             public void run() {
  31.                                 postImg[finalI].setImageBitmap(scaledBitmap);
  32.                             }
  33.                         });
  34.                     } catch (IOException e) {
  35.                         e.printStackTrace();
  36.                     }
  37.                 }
  38.                 progressOFF();
  39.             }
  40.         }).start();
  41.     }

Although this method is performed successfully, there is a problem that the performance speed is too slow.

So I want to know what is faster than this method.

Please help me.

Variable description

postImgUrl : type is ArrayList<String>, this is url that has image i want

postImg : type is ImageView Array, this is ImageView that exists in the layout.

答案1

得分: 1

尝试将for循环放在Thread之外，以便可以同时实例化和处理多个Thread。

  1. public void connectImgtoView(final int max) {
  2.     for (int i = 0; i < max; i++) {
  3.         new Thread(new Runnable() {
  4.             @Override
  5.             public void run() {
  6.                 URL url = null;
  7.                     try {
  8.                         url = new URL(postImgUrl.get(i));
  9.                     } catch (MalformedURLException e) {
  10.                         e.printStackTrace();
  11.                     }
  13.                     try {
  14.                         final BufferedInputStream bufferedInputStream
  15.                                 = new BufferedInputStream(url.openStream());
  16.                         Bitmap bitmap = BitmapFactory.decodeStream(bufferedInputStream);
  17.                         bufferedInputStream.close();
  19.                         final Bitmap scaledBitmap = Bitmap.createScaledBitmap(
  20.                                 bitmap,
  21.                                 (int) (992),
  22.                                 (int) (1403),
  23.                                 true
  24.                         );
  26.                         final int finalI = i;
  27.                         runOnUiThread(new Runnable() {
  28.                             @Override
  29.                             public void run() {
  30.                                 postImg[finalI].setImageBitmap(scaledBitmap);
  31.                             }
  32.                         });
  33.                     } catch (IOException e) {
  34.                         e.printStackTrace();
  35.                     }
  36.                 progressOFF();
  37.             }
  38.         }).start();
  39.     }
  40. }
英文:

Try placing the for loop out side of Thread so that you can instantiate and work multiple Threads simultaneously.

  1. public void connectImgtoView(final int max) {
  2.     for (int i = 0; i &lt; max; i++) {
  3.         new Thread(new Runnable() {
  4.             @Override
  5.             public void run() {
  6.                 URL url = null;
  7.                     try {
  8.                         url = new URL(postImgUrl.get(i));
  9.                     } catch (MalformedURLException e) {
  10.                         e.printStackTrace();
  11.                     }
  13.                     try {
  14.                         final BufferedInputStream bufferedInputStream
  15.                                 = new BufferedInputStream(url.openStream());
  16.                         Bitmap bitmap = BitmapFactory.decodeStream(bufferedInputStream);
  17.                         bufferedInputStream.close();
  19.                         final Bitmap scaledBitmap = Bitmap.createScaledBitmap(
  20.                                 bitmap,
  21.                                 (int) (992),
  22.                                 (int) (1403),
  23.                                 true
  24.                         );
  26.                         final int finalI = i;
  27.                         runOnUiThread(new Runnable() {
  28.                             @Override
  29.                             public void run() {
  30.                                 postImg[finalI].setImageBitmap(scaledBitmap);
  31.                             }
  32.                         });
  33.                     } catch (IOException e) {
  34.                         e.printStackTrace();
  35.                     }
  36.                 progressOFF();
  37.             }
  38.         }).start();
  39.     }
  40. }

huangapple
  • 本文由 发表于 2020年5月2日 14:39:09
  • 转载请务必保留本文链接：https://go.coder-hub.com/61555441.html
  • android
  • android-networking
  • android-threading
  • java
  • performance
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