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我想在 android 中实现它 在此处输入图像描述 为此，我必须从资产文件夹加载图像，我HorizontalScrollView在 xml 文件中制作两个并ImageView在其中动态加载。为了加载 ImageView 我正在使用此代码

LinearLayout myGallery = (LinearLayout) findViewById(R.id.mygallery);

try {
    String galleryDirectoryName = "gallery";
    String[] listImages = getAssets().list(galleryDirectoryName);
    for (String imageName : listImages) {
        InputStream is = getAssets().open(galleryDirectoryName + "/" + imageName);
        Bitmap bitmap = BitmapFactory.decodeStream(is);

        ImageView imageView = new ImageView(getApplicationContext());
        imageView.setLayoutParams(new ViewGroup.LayoutParams(100, 100));

        //   imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setImageBitmap(bitmap);

        LinearLayout.LayoutParams myGallery1=  new LinearLayout.LayoutParams(100, 100);
        myGallery1.setMargins(20, 0,  10, 0);

        //its is also working
        // imageView.setLayoutParams(myGallery1);       

        imageView.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                //   diplayImage.setImageBitmap(bitmap);
            }
        });

        Log.e("GalleryWithHorizontalScrollView", e.getMessage(), e);
    }

//重复上面的代码在第二个horizo​​ntalScrollView中加载imageView

LinearLayout myGallery2 = (LinearLayout) findViewById(R.id.mygallery2);

try {
    String galleryDirectoryName1 = "gallery2";
    String[] listImages2 = getAssets().list(galleryDirectoryName1);
    for (String imageName : listImages2) {
        InputStream is1 = getAssets().open(galleryDirectoryName1 + "/" + imageName);
        Bitmap bitmap1 = BitmapFactory.decodeStream(is1);

        ImageView imageView = new ImageView(getApplicationContext());
        imageView.setLayoutParams(new ViewGroup.LayoutParams(100, 100));

        //  imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setImageBitmap(bitmap1);

        LinearLayout.LayoutParams myGallery21=  new LinearLayout.LayoutParams(100, 100);
        myGallery21.setMargins(20, 40,  10, 0);

        //its is also working

        myGallery.addView(imageView,myGallery1);
    }
} catch (IOException e) {
    myGallery2.addView(imageView,myGallery21);
        }
} catch (IOException e) {
    Log.e("GalleryWithHorizontalScrollView", e.getMessage(), e);
}
}

如果我制作一个horizo​​ntalScrollView 并在其中加载图像视图，那么它可以正常工作，但是对于第二个horizo​​ntalScrollView，它会在第76行给我错误

Bitmap bitmap1 = BitmapFactory.decodeStream(is1);

我的日志猫就是这个

05-14 11:13:26.000: E/AndroidRuntime(8350): FATAL EXCEPTION: main
05-14 11:13:26.000: E/AndroidRuntime(8350): java.lang.OutOfMemoryError
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:577)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:643)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at com.example.gallery.MainActivity.onCreate(MainActivity.java:76)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.app.Activity.performCreate(Activity.java:4470)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.app.ActivityThread.access$600(ActivityThread.java:128)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.os.Looper.loop(Looper.java:137)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at android.app.ActivityThread.main(ActivityThread.java:4517)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at java.lang.reflect.Method.invokeNative(Native Method)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at java.lang.reflect.Method.invoke(Method.java:511)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
05-14 11:13:26.000: E/AndroidRuntime(8350):     at dalvik.system.NativeStart.main(Native Method)
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3 回答 3

1

你可以在这里找到你的答案，

您应该考虑的最重要的事情是优化您的缩略图的位图。尝试这个 ：

public static Bitmap decodeSampledBitmapFromInput(Context context,
        InputStream input, int reqWidth, int reqHeight) {

    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(input, null, options);

    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth,
            reqHeight);

    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    return BitmapFactory.decodeStream(input, null, options);
}

这里 reqWidth 是缩略图的宽度，与 reqHeight 相同。

并且对于 listView 尝试为您的位图实现缓存并尝试通过使用唯一键来获取它们可能是文件名（因为您不应该多次保存相同的图像）

于 2013-05-14T06:33:46.193 回答
0

简单，不要加载太多图像...

使用一些缓存，例如具有固定大小的 LRUCache。如果图像丢失，您必须先加载它们。应该提高性能并修复您的 OOME

http://developer.android.com/reference/android/util/LruCache.html

于 2013-05-14T06:23:34.783 回答
0

您需要使用BitmapFactory.Options访问图像

 BitmapFactory.Options options = new BitmapFactory.Options();
    options.inSampleSize =8;

然后

Bitmap bitmap1 = BitmapFactory.decodeStream(is1,null,options);

这样只有所需大小的位图才会加载到内存中

有关更多信息，请参阅有效加载大型位图

于 2013-05-14T06:32:00.730 回答