Android: Rotate image in imageview by an angle
If you're supporting API 11 or higher, you can just use the following XML attribute:
android:rotation="90"
It might not display correctly in Android Studio xml preview, but it works as expected.
Another simple way to rotate an ImageView
:
UPDATE:
Required imports:
import android.graphics.Matrix;
import android.widget.ImageView;
Code: (Assuming imageView
, angle
, pivotX
& pivotY
are already defined)
Matrix matrix = new Matrix();
imageView.setScaleType(ImageView.ScaleType.MATRIX); //required
matrix.postRotate((float) angle, pivotX, pivotY);
imageView.setImageMatrix(matrix);
This method does not require creating a new bitmap each time.
NOTE: To rotate an
ImageView
on ontouch at runtime you can set onTouchListener onImageView
& rotate it by adding last two lines(i.e. postRotate matrix & set it on imageView) in above code section in your touch listener ACTION_MOVE part.
There are two ways to do that:
1 Using Matrix
to create a new bitmap:
imageView = (ImageView) findViewById(R.id.imageView);
Bitmap myImg = BitmapFactory.decodeResource(getResources(), R.drawable.image);
Matrix matrix = new Matrix();
matrix.postRotate(30);
Bitmap rotated = Bitmap.createBitmap(myImg, 0, 0, myImg.getWidth(), myImg.getHeight(),
matrix, true);
imageView.setImageBitmap(rotated);
2 use RotateAnimation
on the View
you want to Rotate, and make sure the Animation set to fillAfter=true
, duration=0
, and fromDegrees=toDgrees
<?xml version="1.0" encoding="utf-8"?>
<rotate
xmlns:android="http://schemas.android.com/apk/res/android"
android:fromDegrees="45"
android:toDegrees="45"
android:pivotX="50%"
android:pivotY="50%"
android:duration="0"
android:startOffset="0"
/>
and Inflate the Animation in code:
Animation rotation = AnimationUtils.loadAnimation(this, R.anim.rotation);
myView.startAnimation(rotation);
mImageView.setRotation(angle)
with API>=11