Android 位图解码流OutOfMemory异常
我正在我的应用程序中使用自己的Android 位图解码流OutOfMemory异常,android,bitmap,out-of-memory,Android,Bitmap,Out Of Memory,我正在我的应用程序中使用自己的ViewFlowAndroid示例实现。我正在从web服务下载加密图像,然后将它们保存在SD卡上。我正在使用viewflow动态解密图像并显示它们。但问题是,当用户开始太快地更改图像时,它会向我抛出一个OutOfMemoryException,而我发现/测试的所有信息都不适用于我的情况。以下是我正在使用的: @Override public View getView(int position, View convertView, ViewGroup parent)
ViewFlow
Android示例实现。我正在从web服务下载加密图像,然后将它们保存在SD卡上。我正在使用viewflow动态解密图像并显示它们。但问题是,当用户开始太快地更改图像时,它会向我抛出一个OutOfMemoryException
,而我发现/测试的所有信息都不适用于我的情况。以下是我正在使用的:
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = mInflater.inflate(R.layout.image_item, null);
}
try {
File bufferFile = new File(ids.get(position));
FileInputStream fis = new FileInputStream(bufferFile);
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
SecretKeySpec keySpec = new SecretKeySpec("01234567890abcde".getBytes(), "AES");
IvParameterSpec ivSpec = new IvParameterSpec("fedcba9876543210".getBytes());
cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);
CipherInputStream cis = new CipherInputStream(fis, cipher);
BitmapFactory.Options o = new BitmapFactory.Options();
final int REQUIRED_SIZE=300*1024;
//Find the correct scale value. It should be the power of 2.
int width_tmp= o.outWidth, height_tmp= o.outHeight;
int scale=1;
while(true){
if(width_tmp/2<REQUIRED_SIZE || height_tmp/2<REQUIRED_SIZE)
break;
width_tmp/=2;
height_tmp/=2;
scale*=2;
}
//Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
Bitmap ops = BitmapFactory.decodeStream(cis,null,o2);
((ImageView) convertView.findViewById(R.id.imgView)).setImageBitmap(ops);
cis.close();
fis.close();
System.gc();
} catch (Exception e) {
e.printStackTrace();
((ImageView) convertView.findViewById(R.id.imgView)).setImageResource(R.drawable.image_unavailablee);
}
return convertView;
}
有什么办法解决这个问题吗?摘自此处:
试试这个:
BitmapFactory.Options o = new BitmapFactory.Options();
options.inTempStorage = new byte[16*1024];
Bitmap bitmapImage = BitmapFactory.decodeFile(path, options);
而不是:
BitmapFactory.Options o = new BitmapFactory.Options();
final int REQUIRED_SIZE=300*1024;
所以,在使用BitmapFactory.decodeFile()之前,创建一个16kb的字节数组,并在解码过程中将其传递给临时存储器
希望有帮助!
引用:使用回收()。它将释放与此位图关联的本机对象,并清除对像素数据的引用
Bitmap ops = BitmapFactory.decodeStream(cis,null,o2);
((ImageView) convertView.findViewById(R.id.imgView)).setImageBitmap(ops);
cis.close();
fis.close();
ops.recycle();
System.gc();
REQUIRED_SIZE
应包含最大尺寸(宽度、高度,以像素为单位),如
在计算比例因子之前,您还错过了几行将图像边界获取到BitmapFactory.Options o
//Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(cis, null, o);
//The new size we want to scale to
final int REQUIRED_SIZE = 1024;
然后使用o.outWidth
和o.outHeight
计算比例因子。您可能需要再次获取cis
,以便对流进行实际解码
更新:
此外,您还可以将以下变量作为适配器的成员,并在构造函数中进行初始化
SecretKeySpec keySpec = new SecretKeySpec("01234567890abcde".getBytes(), "AES");
IvParameterSpec ivSpec = new IvParameterSpec("fedcba9876543210".getBytes());
这应该没有问题。我一次又一次地遇到同样的问题 这是我的代码,可能有点过火,但我不得不解释这一点,因为不同的相机尺寸,分辨率等,但你必须调整它,以满足你的需要
BitmapFactory.Options imageOptions = new BitmapFactory.Options();
imageOptions.inJustDecodeBounds = true;
ByteArrayInputStream imageByteArrayInputStream = new ByteArrayInputStream(data);
BitmapFactory.decodeStream(imageByteArrayInputStream, null, imageOptions);
System.gc();
// Decode frame size
BitmapFactory.Options frameOptions = new BitmapFactory.Options();
frameOptions.inJustDecodeBounds = true;
BitmapFactory.decodeResource(getResources(), selectedFrameResourceID, frameOptions);
System.gc();
// Scale factor for pre scaling
int preScaleFactor = 1;
if (imageOptions.outWidth > frameOptions.outWidth || imageOptions.outHeight > frameOptions.outHeight) {
preScaleFactor = Math.max(imageOptions.outWidth / frameOptions.outWidth, imageOptions.outHeight / frameOptions.outHeight);
}
// Decode with inSampleSize
BitmapFactory.Options scaleOptions = new BitmapFactory.Options();
scaleOptions.inSampleSize = preScaleFactor;
imageByteArrayInputStream = new ByteArrayInputStream(data);
Bitmap preScaledBitmap = BitmapFactory.decodeStream(imageByteArrayInputStream, null, scaleOptions);
System.gc();
Bitmap finalBitmap;
// Scale factor for precise scaling
// If the scaled image is not exactly the same size as the frame than resize it precisely
if (preScaledBitmap.getWidth() != frameOptions.outWidth || preScaledBitmap.getHeight() != frameOptions.outHeight) {
float scaleFactor = Math.max((float)((float)preScaledBitmap.getWidth() / (float)frameOptions.outWidth), (float)((float)preScaledBitmap.getHeight() / (float)frameOptions.outHeight));
float scalePercentage = Math.min((float)((float)frameOptions.outWidth / (float)preScaledBitmap.getWidth()), (float)((float)frameOptions.outHeight / (float)preScaledBitmap.getHeight()));
Matrix matrix = new Matrix();
matrix.preScale(scalePercentage, scalePercentage);
// If the capture width for the source is bigger than the actual width of the source, then set is to the max of the actual source width
int sourceCaptureWidth = (int)(frameOptions.outWidth * scaleFactor);
if (sourceCaptureWidth > preScaledBitmap.getWidth()) {
sourceCaptureWidth = preScaledBitmap.getWidth();
}
// Same as above but than for the height
int sourceCaptureHeight = (int)(frameOptions.outHeight * scaleFactor);
if (sourceCaptureHeight > preScaledBitmap.getHeight()) {
sourceCaptureHeight = preScaledBitmap.getHeight();
}
finalBitmap = Bitmap.createBitmap(preScaledBitmap, 0, 0, sourceCaptureWidth, sourceCaptureHeight, matrix, true);
preScaledBitmap.recycle();
preScaledBitmap = null;
希望这有帮助你在哪个版本的Android上运行这个?如果您在Honeycom或更高版本上运行它,您应该能够使用Eclipse内存分析器查看内存的使用位置 也就是说,一旦不再需要或显示位图,就需要对其调用recycle()(这是Sujit答案的问题)。换句话说,如果位图从屏幕上消失,最好将其循环使用(),然后在返回视图时重新加载。否则,该位图就是usi 为此,在ImageView上调用getDrawable(),在ImageView上调用setImageDrawable(null),然后将drawable强制转换为BitmapDrawable,并在其中循环使用位图
有关Android 3.0之前位图内存如何工作的更多信息,您可以看到我在这个问题上的一篇帖子:仅供处理大型位图的人员参考,有一篇文章介绍了如何处理此类问题以避免内存不足的最佳方法
希望有帮助 当我尝试使用recycle时,它抛出了一个异常:java.lang.RuntimeException:Canvas:尝试使用一个回收的位图android.graphics。Bitmap@40627090,640x960您可以在finally块中使用recycle()。尝试这样做。事实上,我在getView函数中实现了延迟加载,目前它运行正常,没有任何错误。我想整个问题在于我在getView函数中解码流,它分配了太多内存。无论如何,谢谢你的回答!如果它仍然给我一个错误,我会尝试你的解决方案。没问题,我很高兴你能解决它。我想向你致敬,先生。几年前,我发明了自己的例行程序来做同样的事情,但我更喜欢你的。非常令人印象深刻。虽然我最终偷了机器人提供的“提示”,从莱昂纳多·阿兰戈·巴埃纳的答案,这几乎像是作弊!这是我见过的最好、最干净、最重要、最快的方法。非常感谢您的分享。有时,最好的信息是安卓小组创建的或写的博客,但这是我最后一次看到的地方。
SecretKeySpec keySpec = new SecretKeySpec("01234567890abcde".getBytes(), "AES");
IvParameterSpec ivSpec = new IvParameterSpec("fedcba9876543210".getBytes());
BitmapFactory.Options imageOptions = new BitmapFactory.Options();
imageOptions.inJustDecodeBounds = true;
ByteArrayInputStream imageByteArrayInputStream = new ByteArrayInputStream(data);
BitmapFactory.decodeStream(imageByteArrayInputStream, null, imageOptions);
System.gc();
// Decode frame size
BitmapFactory.Options frameOptions = new BitmapFactory.Options();
frameOptions.inJustDecodeBounds = true;
BitmapFactory.decodeResource(getResources(), selectedFrameResourceID, frameOptions);
System.gc();
// Scale factor for pre scaling
int preScaleFactor = 1;
if (imageOptions.outWidth > frameOptions.outWidth || imageOptions.outHeight > frameOptions.outHeight) {
preScaleFactor = Math.max(imageOptions.outWidth / frameOptions.outWidth, imageOptions.outHeight / frameOptions.outHeight);
}
// Decode with inSampleSize
BitmapFactory.Options scaleOptions = new BitmapFactory.Options();
scaleOptions.inSampleSize = preScaleFactor;
imageByteArrayInputStream = new ByteArrayInputStream(data);
Bitmap preScaledBitmap = BitmapFactory.decodeStream(imageByteArrayInputStream, null, scaleOptions);
System.gc();
Bitmap finalBitmap;
// Scale factor for precise scaling
// If the scaled image is not exactly the same size as the frame than resize it precisely
if (preScaledBitmap.getWidth() != frameOptions.outWidth || preScaledBitmap.getHeight() != frameOptions.outHeight) {
float scaleFactor = Math.max((float)((float)preScaledBitmap.getWidth() / (float)frameOptions.outWidth), (float)((float)preScaledBitmap.getHeight() / (float)frameOptions.outHeight));
float scalePercentage = Math.min((float)((float)frameOptions.outWidth / (float)preScaledBitmap.getWidth()), (float)((float)frameOptions.outHeight / (float)preScaledBitmap.getHeight()));
Matrix matrix = new Matrix();
matrix.preScale(scalePercentage, scalePercentage);
// If the capture width for the source is bigger than the actual width of the source, then set is to the max of the actual source width
int sourceCaptureWidth = (int)(frameOptions.outWidth * scaleFactor);
if (sourceCaptureWidth > preScaledBitmap.getWidth()) {
sourceCaptureWidth = preScaledBitmap.getWidth();
}
// Same as above but than for the height
int sourceCaptureHeight = (int)(frameOptions.outHeight * scaleFactor);
if (sourceCaptureHeight > preScaledBitmap.getHeight()) {
sourceCaptureHeight = preScaledBitmap.getHeight();
}
finalBitmap = Bitmap.createBitmap(preScaledBitmap, 0, 0, sourceCaptureWidth, sourceCaptureHeight, matrix, true);
preScaledBitmap.recycle();
preScaledBitmap = null;