Android：如何在设置图像视图时检测从图库中选择的图像方向（纵向或横向）？

Question

我正在从画廊（相机相册）挑选的图像视图上设置图像。如果选择的图像是横向的，它会完美显示，但如果图像是纵向模式（即图像是在纵向模式下单击的），它会以 90 度旋转显示图像。现在我试图在设置 imageview 之前找出方向，但所有图像都给出相同的方向和相同的宽度高度。这是我的代码：

Uri selectedImage = intent.getData();
if (selectedImage != null) {
    Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), selectedImage);

    int str = new ExifInterface(selectedImage.getPath()).getAttributeInt("Orientation", 1000);
    Toast.makeText(this, "value:" + str, Toast.LENGTH_LONG).show();
    Toast.makeText(this, "width:" + bitmap.getWidth() + "height:" + bitmap.getHeight(), Toast.LENGTH_LONG).show();

Answer 1

使用ExifInterface 旋转图像。使用此方法获取正确的值以从相机旋转捕获的图像。

public int getCameraPhotoOrientation(Context context, Uri imageUri, String imagePath){
    int rotate = 0;
    try {
        context.getContentResolver().notifyChange(imageUri, null);
        File imageFile = new File(imagePath);

        ExifInterface exif = new ExifInterface(imageFile.getAbsolutePath());
        int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

        switch (orientation) {
        case ExifInterface.ORIENTATION_ROTATE_270:
            rotate = 270;
            break;
        case ExifInterface.ORIENTATION_ROTATE_180:
            rotate = 180;
            break;
        case ExifInterface.ORIENTATION_ROTATE_90:
            rotate = 90;
            break;
        }

        Log.i("RotateImage", "Exif orientation: " + orientation);
        Log.i("RotateImage", "Rotate value: " + rotate);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return rotate;
}

并将这段代码放入Activity结果方法并获取旋转图像的值...

String selectedImage = data.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};

Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
cursor.moveToFirst();

int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
filePath = cursor.getString(columnIndex);
cursor.close();

int rotateImage = getCameraPhotoOrientation(MyActivity.this, selectedImage, filePath);

希望这会有所帮助..

Answer 2

这也对我有用：

String[] orientationColumn = {MediaStore.Images.Media.ORIENTATION};
Cursor cur = getContentResolver().query(imageUri, orientationColumn, null, null, null);
int orientation = -1;
if (cur != null && cur.moveToFirst()) {
    orientation = cur.getInt(cur.getColumnIndex(orientationColumn[0]));
}
Matrix matrix = new Matrix();
matrix.postRotate(orientation);

Answer 3

                      if(bm.getWidth() > bm.getHeight())
                        {
                            Bitmap bMapRotate=null;
                            Matrix mat=new Matrix();
                            mat.postRotate(90);
                        bMapRotate = Bitmap.createBitmap(bm, 0, 0,bm.getWidth(),bm.getHeight(), mat, true);
                        bm.recycle();
                        bm=null;
                        imageDisplayView.setImageBitmap(bMapRotate);
                        }else
                        imageDisplayView.setImageBitmap(bm);

Answer 4

这是我遇到的一个很好的解决方案：>https://stackoverflow.com/a/34241250/8033090

一线解决方案：

Picasso.with(context).load("http://i.imgur.com/DvpvklR.png").into(imageView);

或

Picasso.with(context).load("file:" + photoPath).into(imageView);

这将自动检测旋转并将图像放置在正确的方向

Picasso 是一个非常强大的库，用于在您的应用中处理图像，包括： 使用最少内存的复杂图像转换。加载可能需要一秒钟，但我只是在图像视图后面放了一些文本，上面写着“正在加载图像”，并且当图像加载时它会覆盖文本。

Answer 5

使用 kotlin 并考虑新 android 版本中 uri 和 exif 的变化：

 var exif: ExifInterface? = null;
 try {
    when (Build.VERSION.SDK_INT) {
        in Int.MIN_VALUE..24 -> exif = ExifInterface(imageUri.path)
        else -> exif = ExifInterface(getContentResolver().openInputStream(data.extras.get("data")))
     }
 } catch (e: IOException) {
     e.printStackTrace();
 }
 val orientation = exif?.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL)
 bmp = rotateBitmap(bmp, orientation ?: ExifInterface.ORIENTATION_NORMAL)

而rotateBitmap函数是：

un rotateBitmap(bitmap: Bitmap, orientation: Int): Bitmap {
val matrix = Matrix()
when (orientation) {
    ExifInterface.ORIENTATION_NORMAL -> return bitmap
    ExifInterface.ORIENTATION_FLIP_HORIZONTAL -> matrix.setScale(-1f, 1f)
    ExifInterface.ORIENTATION_ROTATE_180 -> matrix.setRotate(180f)
    ExifInterface.ORIENTATION_FLIP_VERTICAL -> {
        matrix.setRotate(180f)
        matrix.postScale(-1f, 1f)
    }
    ExifInterface.ORIENTATION_TRANSPOSE -> {
        matrix.setRotate(90f)
        matrix.postScale(-1f, 1f)
    }
    ExifInterface.ORIENTATION_ROTATE_90 -> matrix.setRotate(90f)
    ExifInterface.ORIENTATION_TRANSVERSE -> {
        matrix.setRotate(-90f)
        matrix.postScale(-1f, 1f)
    }
    ExifInterface.ORIENTATION_ROTATE_270 -> matrix.setRotate(-90f)
    else -> return bitmap
}
try {
    val bmRotated = Bitmap.createBitmap(bitmap, 0, 0, bitmap.width, bitmap.height, matrix, true)
    bitmap.recycle()
    return bmRotated
} catch (e: OutOfMemoryError) {
    e.printStackTrace()
    return null
}

}

Answer 6

在某些安卓设备上使用 EXIF 信息不可靠。 (ExifInterface 方向总是返回 0)

这对我有用：

旋转位图

public static Bitmap rotateBitmap(Context context, Uri photoUri, Bitmap bitmap) 
{
    int orientation = getOrientation(context, photoUri);
    if (orientation <= 0) {
        return bitmap;
    }

    Matrix matrix = new Matrix();
    matrix.postRotate(orientation);
    bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, false);
    return bitmap;
}

从 MediaStore 获取方向

private static int getOrientation(Context context, Uri photoUri) 
{
    Cursor cursor = context.getContentResolver().query(photoUri,
            new String[]{MediaStore.Images.ImageColumns.ORIENTATION}, null, null, null);

    if (cursor.getCount() != 1) {
        cursor.close();
        return -1;
    }

    cursor.moveToFirst();
    int orientation = cursor.getInt(0);
    cursor.close();
    cursor = null;
    return orientation;
}

Answer 7

另一种解决方案是使用支持库中的 ExifInterface： ExifInterface from support library

Answer 8

这对我有用：

private String getOrientation(Uri uri){
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    String orientation = "landscape";
    try{
        String image = new File(uri.getPath()).getAbsolutePath();
        BitmapFactory.decodeFile(image, options);
        int imageHeight = options.outHeight;
        int imageWidth = options.outWidth;
        if (imageHeight > imageWidth){
            orientation = "portrait";
        }
    }catch (Exception e){
        //Do nothing
    }
    return orientation;
}