Android动画围绕其中心点旋转图像

Question

I am struggling with an android xml animation. I want to rotate an image anti clockwise around its central point.

Here is my xml for the animation:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:fillAfter="true" >

<rotate
    android:duration="1000"
    android:repeatCount="infinite"
    android:repeatMode="restart"
    android:fromDegrees="360"
    android:toDegrees="0"
    android:pivotX="0.5"
    android:pivotY="0.5"         
    android:interpolator="@android:anim/linear_interpolator"        
   />

No this current animation rotates the image around the point x=0 ; y=0 .

Answer 1

Answering on behalf of @Mahfa

You have to set pivotX and pivotY to "50%"

The important part is the percentage.

Answer 2

I think that you need to use a Matrix object. I did the same some time ago and I remember that I had the same issue than you:

Bitmap targetBitmap = Bitmap.createBitmap(targetWidth, targetHeight, config);
Canvas canvas = new Canvas(targetBitmap);
Matrix matrix = new Matrix();
matrix.setRotate(mRotation,source.getWidth()/2,source.getHeight()/2);
canvas.drawBitmap(source, matrix, new Paint());

Edit: use this function with a timer handler

public Bitmap rotateImage(int angle, Bitmap bitmapSrc) {
Matrix matrix = new Matrix();
matrix.postRotate(angle);
return Bitmap.createBitmap(bitmapSrc, 0, 0, 
        bitmapSrc.getWidth(), bitmapSrc.getHeight(), matrix, true);

}