Question

我可以从手机中检索图片并将其存储在一个阵列中。之后我在屏幕上显示它们。但它们都有不同的形状和大小。我想以相同的尺寸和形状显示它们。有什么想法吗？

photoPaths = new ArrayList<String>();   
     getAllPhotos(Environment.getExternalStorageDirectory(), photoPaths);
     images = new Bitmap[photoPaths.size()];


         apa = (AnimationPhotoView)findViewById(R.id.animation_view);
        for(int i=0;i<photoPaths.size();i++)
        {
            File imgFile = new  File(photoPaths.get(0));

            if(imgFile.exists())
            {

                images[0] = decodeFile(imgFile);}

Answer 1

    Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),R.drawable.tedd);

    int width = bitmapOrg.getWidth();

    int height = bitmapOrg.getHeight();


    int newWidth = 200;

    int newHeight  = 200;

    // calculate the scale - in this case = 0.4f

     float scaleWidth = ((float) newWidth) / width;

     float scaleHeight = ((float) newHeight) / height;

     Matrix matrix = new Matrix();

     matrix.postScale(scaleWidth, scaleHeight);
     matrix.postRotate(x);
     // this will create image with new size
     Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,width, height, matrix, true);

     iv.setScaleType(ScaleType.CENTER);
     iv.setImageBitmap(resizedBitmap);

Answer 2

我正在使用：

Bitmap bitmap = //Your source

int newWidth = //compute new width
int newHeight = //compute new height

bitmap = Bitmap.createScaledBitmap(bitmap, scaleWidth, scaleHeight, true);

最后boolean为filter，可让您的图片更流畅。

上面MAC提出的解决方案给了我一个IllegalArgumentException: bitmap size exceeds 32bits。

这只会缩放位图，但不会旋转它。

Answer 3

如果您只想显示由android“知道”的jpg图像或图像格式，您可以简单地使用MediaStore.Images并检索缩略图，这样更快且需要更少的内存，图像应该已经全部相同的格式（宽度+高度）。

http://developer.android.com/reference/android/provider/MediaStore.Images.html

Answer 4

我想你也可以尝试一下。

private Bitmap decodeFile(File f)
{
    try 
    {
        //decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f),null,o);
        //Find the correct scale value. It should be the power of 2.
        final int REQUIRED_SIZE=200;
        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;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {}
    return null;
}

在Android中以编程方式放大图片

4 个答案: