如何传递没有得到OutOfMemory错误两项活动之间的图像路径？ [英] How do you pass an image path between two activities without getting outofMemory error?
问题描述
因此，基本上，用户点击一个按钮，它从库中抓取的图像。然后该图像被发送到要被显示另一个活动。这是我抢的形象我的第一个活动。
私人无效grabImage（）
{
意图imageGetter =新意图（Intent.ACTION_PICK，MediaStore.Images.Media.EXTERNAL_CONTENT_URI）;
startActivityForResult（imageGetter，RESULT_LOAD_IMAGE）;
}@覆盖
保护无效的onActivityResult（INT申请code，INT结果code，意图数据）
{
super.onActivityResult（要求code，结果code，数据）;
如果（要求code == RESULT_LOAD_IMAGE＆放大器;＆安培;结果code == RESULT_OK＆放大器;＆安培;！NULL =数据）
{
乌里selectedImage = data.getData（）;
的String [] = filePathColumn {MediaStore.Images.Media.DATA}; // 1数组大小，我们把在一个字符串
光标光标= getContentResolver（）查询（selectedImage，filePathColumn，NULL，NULL，NULL）;
cursor.moveToFirst（）;
INT参数：columnIndex = cursor.getColumnIndex（filePathColumn [0]）;
user_image_path = cursor.getString（参数：columnIndex）; //这里，我们有我们的形象路径。
cursor.close（）;
ImageView的ImageView的=（ImageView的）findViewById（R.id.imageView）;
imageView.setImageBitmap（BitmapFactory.de codeFILE（user_image_path））;
} 意图theIntent =新意图（这一点，CardModel.class）;
theIntent.putExtra（的ImagePath，user_image_path）;
}
现在这是一个尝试显示图像我的第二个活动。
@覆盖
公共无效的onCreate（捆绑savedInstanceState）
{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.card_model_layout）;
串grabImagePath = getIntent（）getStringExtra（的ImagePath）;
ImageView的IMG =（ImageView的）findViewById（R.id.userImage）;
img.setImageBitmap（BitmapFactory.de codeFILE（grabImagePath））; }
我不断收到的OutOfMemoryError错误，我不想加：
机器人：largeHeap =真来解决问题。
有人可以给我一个干净的切割为例（与所有code）对如何正确传递图像两项活动之间（使用它的字符串路径）。我敢肯定，很多开发者可以从中受益。谢谢！
另外有没有办法做到这一点，而无需调用的onActivityResult，反而只是让你自己的方法，并把code在那里，并呼吁，在onCreate（）方法。
事实是 -
既然你用有限的内存的工作，理想情况下，你只需要
在存储器加载较低分辨率版本。较低的分辨率
版本应该匹配其显示UI组件的大小。一个
具有较高分辨率的图像不提供任何可见的好处，
但是仍然占据precious内存并造成额外的性能
由于开销额外动态缩放。[参考链接： http://developer.android.com /training/displaying-bitmaps/load-bitmap.html]
这就是为什么你需要缩小图像。希望下面的code可以帮助你！
进口android.graphics.Bitmap;
进口android.graphics.BitmapFactory;公共类BitmapUtility { 公共静态位图德codeSampledBitmapFromResource（字符串路径，INT reqWidth，诠释reqHeight）{ //首先去code。与inJustDe codeBounds = true来检查尺寸
最后BitmapFactory.Options选项=新BitmapFactory.Options（）;
options.inJustDe codeBounds = TRUE;
BitmapFactory.de codeFILE（路径选择）; //计算inSampleSize
options.inSampleSize = calculateInSampleSize（选项，reqWidth，reqHeight）; //德code位与inSampleSize集
options.inJustDe codeBounds = FALSE;
返回BitmapFactory.de codeFILE（路径选择）;
}
私有静态诠释calculateInSampleSize（
BitmapFactory.Options选项，诠释reqWidth，诠释reqHeight）{
//原始高度和图像宽度
最终诠释身高= options.outHeight;
最终诠释宽度= options.outWidth;
INT inSampleSize = 1; 如果（高度＆GT; reqHeight ||宽度GT; reqWidth）{ 最终诠释halfHeight =身高/ 2;
最终诠释半宽度=宽度/ 2; //计算最大inSampleSize值是2的幂，并保持这两个
//高度和宽度大于所请求的高度和宽度。
而（（halfHeight / inSampleSize）GT; reqHeight
＆功放;＆安培; （半角/ inSampleSize）GT; reqWidth）{
inSampleSize * = 2;
}
} 返回inSampleSize;
}
}您可以使用上面code如下：
而不是使用的：imageView.setImageBitmap（BitmapFactory.de codeFILE（user_image_path））;您可以使用：
<$p$p><$c$c>imageView.setImageBitmap(BitmapUtilty.de$c$cSampledBitmapFromResource(\"path/to/image\",300,400)
So basically, a user click a button and it grabs an image from the gallery. Then that image is sent to another activity to be displayed. This is my first activity where I grab the image.
private void grabImage() { Intent imageGetter = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI); startActivityForResult(imageGetter, RESULT_LOAD_IMAGE); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if(requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) { Uri selectedImage = data.getData(); String[] filePathColumn = {MediaStore.Images.Media.DATA};//Array size of 1, and we put in a string Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null); cursor.moveToFirst(); int columnIndex = cursor.getColumnIndex(filePathColumn[0]); user_image_path = cursor.getString(columnIndex);//here we have our image path. cursor.close(); ImageView imageView = (ImageView) findViewById(R.id.imageView); imageView.setImageBitmap(BitmapFactory.decodeFile(user_image_path)); } Intent theIntent = new Intent(this,CardModel.class); theIntent.putExtra("imagePath", user_image_path); }Now this is my second activity that tries to display that image.
@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.card_model_layout); String grabImagePath = getIntent().getStringExtra("imagePath"); ImageView img = (ImageView) findViewById(R.id.userImage); img.setImageBitmap(BitmapFactory.decodeFile(grabImagePath)); }I keep getting OutOfMemoryError error and I don't wanna add: android:largeHeap="true" to solve the problem.
Can someone give me a clean cut example (with all the code) of how to properly pass an image (using its string path) between two activities. I'm sure a lot of developers could benefit from this. Thanks!
Also is there a way to do this without calling onActivityResult and instead just make you're own method and put the code in there and call that in the onCreate() method.
解决方案The fact is-
Given that you are working with limited memory, ideally you only want to load a lower resolution version in memory. The lower resolution version should match the size of the UI component that displays it. An image with a higher resolution does not provide any visible benefit, but still takes up precious memory and incurs additional performance overhead due to additional on the fly scaling.
[Reference Link : http://developer.android.com/training/displaying-bitmaps/load-bitmap.html]
That's why you need to scale down images . Hope, following code will help you !
import android.graphics.Bitmap; import android.graphics.BitmapFactory; public class BitmapUtility { public static Bitmap decodeSampledBitmapFromResource(String path,int reqWidth, int reqHeight) { // First decode with inJustDecodeBounds=true to check dimensions final BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; BitmapFactory.decodeFile(path,options); // Calculate inSampleSize options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); // Decode bitmap with inSampleSize set options.inJustDecodeBounds = false; return BitmapFactory.decodeFile(path, options); } private static int calculateInSampleSize( BitmapFactory.Options options, int reqWidth, int reqHeight) { // Raw height and width of image final int height = options.outHeight; final int width = options.outWidth; int inSampleSize = 1; if (height > reqHeight || width > reqWidth) { final int halfHeight = height / 2; final int halfWidth = width / 2; // Calculate the largest inSampleSize value that is a power of 2 and keeps both // height and width larger than the requested height and width. while ((halfHeight / inSampleSize) > reqHeight && (halfWidth / inSampleSize) > reqWidth) { inSampleSize *= 2; } } return inSampleSize; } }You can use above code as follows: Instead of using:
imageView.setImageBitmap(BitmapFactory.decodeFile(user_image_path));you can use:
imageView.setImageBitmap(BitmapUtilty.decodeSampledBitmapFromResource("path/to/image",300,400)
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